refactor: abstract database layer to support MySQL and SQL Server

- Add IDatabaseService interface with unified query(transaction) methods
- Create DatabaseFactory for centralized database service creation
- Modify MySqlService and SqlServerService to implement IDatabaseService
- Unify SqlServerService.query() to accept array params (internally converts to @p0, @p1...)
- Refactor OrderNumberResolver to use IDatabaseService
- Refactor DiscreteMaterialPlanDAO to use DatabaseFactory
- Refactor MaterialsToBeDeletedDAO to use DatabaseFactory
- Update IPC handlers to use DatabaseFactory.create()
- Add database.types.ts with shared type definitions

This enables switching between MySQL and SQL Server via DB_TYPE env variable.

Co-Authored-By: Claude (glm-5) <noreply@anthropic.com>

src/main/ipc/database-handler.ts

@@ -214,7 +214,18 @@ export function registerDatabaseHandlers(): void {
         }
 
         log.debug('Executing SQL Server query', { windowId, sql: sqlString.substring(0, 100) })
-        return await service.query(sqlString, params)
+
+        // Use queryWithParams for named parameters, or query for no params
+        if (params && Object.keys(params).length > 0) {
+          // Convert to the format expected by queryWithParams
+          const typedParams: Record<string, { value: unknown }> = {}
+          for (const [key, value] of Object.entries(params)) {
+            typedParams[key] = { value }
+          }
+          return await service.queryWithParams(sqlString, typedParams)
+        } else {
+          return await service.query(sqlString)
+        }
       } catch (error) {
         const message = error instanceof Error ? error.message : 'SQL Server query failed'
         log.error('SQL Server query failed', { error: message })

src/main/ipc/extractor-handler.ts

@@ -2,7 +2,7 @@ import { ipcMain } from 'electron'
 import { ErpAuthService } from '../services/erp/erp-auth'
 import { ExtractorService } from '../services/erp/extractor'
 import { OrderNumberResolver } from '../services/erp/order-resolver'
-import { MySqlService } from '../services/database/mysql'
+import { create, type IDatabaseService } from '../services/database'
 import { createLogger } from '../services/logger'
 import { withErrorHandling, type IpcResult } from './index'
 import { ErpConnectionError, ValidationError, DatabaseQueryError } from '../types/errors'
@@ -19,7 +19,7 @@ export function registerExtractorHandlers(): void {
     async (_event, input: ExtractorInput): Promise<IpcResult<ExtractorResult>> => {
       return withErrorHandling(async () => {
         let authService: ErpAuthService | null = null
-        let mysqlService: MySqlService | null = null
+        let dbService: IDatabaseService | null = null
 
         try {
           // Check environment variables
@@ -39,29 +39,20 @@ export function registerExtractorHandlers(): void {
             )
           }
 
-          // Resolve order numbers (convert productionIDs to 生产订单号)
+          // Create database service using factory
-          const mysqlConfig = {
+          log.info('Connecting to database for order resolution...')
-            host: process.env.DB_MYSQL_HOST || 'localhost',
-            port: parseInt(process.env.DB_MYSQL_PORT || '3306', 10),
-            user: process.env.DB_USERNAME || 'root',
-            password: process.env.DB_PASSWORD || '',
-            database: process.env.DB_NAME || ''
-          }
-
-          log.info('Connecting to MySQL for order resolution...')
-          mysqlService = new MySqlService(mysqlConfig)
-
           try {
-            await mysqlService.connect()
+            dbService = await create()
           } catch (error) {
             throw new DatabaseQueryError(
-              'MySQL 连接失败',
+              '数据库连接失败',
               'DB_CONNECTION_FAILED',
               error instanceof Error ? error : undefined
             )
           }
 
-          const resolver = new OrderNumberResolver(mysqlService)
+          // Resolve order numbers (convert productionIDs to 生产订单号)
+          const resolver = new OrderNumberResolver(dbService)
           const mappings = await resolver.resolve(input.orderNumbers)
 
           // Get valid order numbers and warnings
@@ -136,13 +127,13 @@ export function registerExtractorHandlers(): void {
             }
           }
 
-          // Clean up: disconnect MySQL
+          // Clean up: disconnect database
-          if (mysqlService) {
+          if (dbService) {
             try {
-              await mysqlService.disconnect()
+              await dbService.disconnect()
-              log.debug('MySQL disconnected')
+              log.debug('Database disconnected')
             } catch (closeError) {
-              log.warn('Error disconnecting MySQL', {
+              log.warn('Error disconnecting database', {
                 error: closeError instanceof Error ? closeError.message : String(closeError)
               })
             }

src/main/ipc/resolver-handler.ts

@@ -7,10 +7,9 @@
  */
 
 import { ipcMain } from 'electron'
-import { MySqlService } from '../services/database/mysql'
+import { create, type IDatabaseService } from '../services/database'
 import { OrderNumberResolver } from '../services/erp/order-resolver'
 import { createLogger } from '../services/logger'
-import { DatabaseQueryError } from '../types/errors'
 import type { OrderMapping, ResolutionStats } from '../services/erp/order-resolver'
 
 const log = createLogger('ResolverHandler')
@@ -21,14 +20,6 @@ const log = createLogger('ResolverHandler')
 export interface ResolverInput {
   /** List of order numbers/productionIDs to resolve */
   inputs: string[]
-  /** MySQL configuration (optional, uses default if not provided) */
-  mysqlConfig?: {
-    host: string
-    port: number
-    user: string
-    password: string
-    database: string
-  }
 }
 
 /**
@@ -60,25 +51,15 @@ export function registerResolverHandlers(): void {
   ipcMain.handle(
     'resolver:resolve',
     async (_event, input: ResolverInput): Promise<ResolverResponse> => {
-      let mysqlService: MySqlService | null = null
+      let dbService: IDatabaseService | null = null
 
       try {
-        // Use provided config or environment variables
+        // Create database service using factory
-        const mysqlConfig = input.mysqlConfig || {
+        log.info('Connecting to database for resolution', { inputCount: input.inputs.length })
-          host: process.env.DB_MYSQL_HOST || 'localhost',
+        dbService = await create()
-          port: parseInt(process.env.DB_MYSQL_PORT || '3306', 10),
-          user: process.env.DB_USERNAME || 'root',
-          password: process.env.DB_PASSWORD || '',
-          database: process.env.DB_NAME || ''
-        }
-
-        // Create MySQL service
-        log.info('Connecting to MySQL for resolution', { inputCount: input.inputs.length })
-        mysqlService = new MySqlService(mysqlConfig)
-        await mysqlService.connect()
 
         // Create resolver and resolve inputs
-        const resolver = new OrderNumberResolver(mysqlService)
+        const resolver = new OrderNumberResolver(dbService)
         const mappings = await resolver.resolve(input.inputs)
 
         // Get valid order numbers and warnings
@@ -107,13 +88,13 @@ export function registerResolverHandlers(): void {
           error: `解析失败：${message}`
         }
       } finally {
-        // Clean up MySQL connection
+        // Clean up database connection
-        if (mysqlService) {
+        if (dbService) {
           try {
-            await mysqlService.disconnect()
+            await dbService.disconnect()
-            log.debug('MySQL disconnected')
+            log.debug('Database disconnected')
           } catch (closeError) {
-            log.warn('Error disconnecting MySQL', {
+            log.warn('Error disconnecting database', {
               error: closeError instanceof Error ? closeError.message : String(closeError)
             })
           }
@@ -136,9 +117,11 @@ export function registerResolverHandlers(): void {
       error?: string
     }> => {
       try {
+        // Create a mock resolver without database connection
         const resolver = new OrderNumberResolver({
-          isConnected: () => false
+          isConnected: () => false,
-        } as MySqlService)
+          type: 'mysql'
+        } as IDatabaseService)
 
         const results = inputs.map((input) => ({
           input,

src/main/services/database/discrete-material-plan-dao.ts

@@ -8,9 +8,7 @@
  * - Statistics gathering
  */
 
-import { MySqlService } from './mysql'
+import { create, type IDatabaseService } from './index'
-import { SqlServerService } from './sql-server'
-import sql from 'mssql'
 import { createLogger } from '../logger'
 
 const log = createLogger('DiscreteMaterialPlanDAO')
@@ -95,70 +93,37 @@ export const DISCRETE_MATERIAL_PLAN_CONFIG = {
  * DiscreteMaterialPlanDAO Class
  */
 export class DiscreteMaterialPlanDAO {
-  private mysqlService: MySqlService | null = null
+  private dbService: IDatabaseService | null = null
-  private sqlServerService: SqlServerService | null = null
-  private dbType: 'mysql' | 'sqlserver' = 'mysql'
-
-  /**
-   * Constructor - determine database type from environment
-   */
-  constructor() {
-    const dbType = process.env.DB_TYPE?.toLowerCase()
-    if (dbType === 'sqlserver' || dbType === 'mssql') {
-      this.dbType = 'sqlserver'
-    } else {
-      this.dbType = 'mysql'
-    }
-  }
 
   /**
    * Get the appropriate table name based on database type
    */
   private getTableName(): string {
-    return this.dbType === 'sqlserver'
+    const isSqlServer = this.dbService?.type === 'sqlserver'
+    return isSqlServer
       ? DISCRETE_MATERIAL_PLAN_CONFIG.TABLE_NAME_SQLSERVER
       : DISCRETE_MATERIAL_PLAN_CONFIG.TABLE_NAME_MYSQL
   }
 
   /**
-   * Get database service instance (MySQL or SQL Server)
+   * Get database service instance using DatabaseFactory
    */
-  private async getDatabaseService(): Promise<MySqlService | SqlServerService> {
+  private async getDatabaseService(): Promise<IDatabaseService> {
-    if (this.dbType === 'sqlserver') {
+    if (this.dbService && this.dbService.isConnected()) {
-      if (this.sqlServerService && this.sqlServerService.isConnected()) {
+      return this.dbService
-        return this.sqlServerService
-      }
-
-      this.sqlServerService = new SqlServerService({
-        server: process.env.DB_SERVER || 'localhost',
-        port: parseInt(process.env.DB_SQLSERVER_PORT || '1433', 10),
-        user: process.env.DB_USERNAME || 'sa',
-        password: process.env.DB_PASSWORD || '',
-        database: process.env.DB_NAME || '',
-        options: {
-          encrypt: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes',
-          trustServerCertificate: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes'
-        }
-      })
-
-      await this.sqlServerService.connect()
-      return this.sqlServerService
-    } else {
-      if (this.mysqlService && this.mysqlService.isConnected()) {
-        return this.mysqlService
-      }
-
-      this.mysqlService = new MySqlService({
-        host: process.env.DB_MYSQL_HOST || 'localhost',
-        port: parseInt(process.env.DB_MYSQL_PORT || '3306', 10),
-        user: process.env.DB_USERNAME || 'root',
-        password: process.env.DB_PASSWORD || '',
-        database: process.env.DB_NAME || ''
-      })
-
-      await this.mysqlService.connect()
-      return this.mysqlService
     }
+
+    this.dbService = await create()
+    return this.dbService
+  }
+
+  /**
+   * Build placeholders for IN clause based on database type
+   */
+  private buildPlaceholders(count: number, isSqlServer: boolean): string {
+    return isSqlServer
+      ? Array.from({ length: count }, (_, idx) => `@p${idx}`).join(',')
+      : Array.from({ length: count }, () => '?').join(',')
   }
 
   // ==================== QUERY ALL ====================
@@ -173,11 +138,7 @@ export class DiscreteMaterialPlanDAO {
       const tableName = this.getTableName()
 
       const sqlString = `SELECT * FROM ${tableName}`
-
+      const result = await dbService.query(sqlString)
-      const result =
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
 
       return result.rows
     } catch (error) {
@@ -221,11 +182,7 @@ export class DiscreteMaterialPlanDAO {
         WHERE rn = 1
       `
 
-      const result =
+      const result = await dbService.query(sqlString)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return result.rows
     } catch (error) {
       log.error('Query all distinct by material code error', {
@@ -250,40 +207,22 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
       const batchSize = 2000
       const allResults: any[] = []
 
       for (let i = 0; i < sourceNumbers.length; i += batchSize) {
         const batch = sourceNumbers.slice(i, i + batchSize)
+        const placeholders = this.buildPlaceholders(batch.length, isSqlServer)
 
-        if (this.dbType === 'sqlserver') {
+        const sqlString = `
-          const placeholders = batch.map((_, idx) => `@p${idx}`).join(',')
+          SELECT *
-          const params: Record<string, { value: string; type: sql.ISqlType }> = {}
+          FROM ${tableName}
+          WHERE SourceNumber IN (${placeholders})
+        `
 
-          batch.forEach((num, idx) => {
+        const result = await dbService.query(sqlString, batch)
-            params[`p${idx}`] = { value: num, type: sql.NVarChar }
+        allResults.push(...result.rows)
-          })
-
-          const sqlString = `
-            SELECT *
-            FROM ${tableName}
-            WHERE SourceNumber IN (${placeholders})
-          `
-
-          const result = await (dbService as SqlServerService).queryWithParams(sqlString, params)
-          allResults.push(...result.rows)
-        } else {
-          const placeholders = batch.map(() => '?').join(',')
-
-          const sqlString = `
-            SELECT *
-            FROM ${tableName}
-            WHERE SourceNumber IN (${placeholders})
-          `
-
-          const result = await (dbService as MySqlService).query(sqlString, batch)
-          allResults.push(...result.rows)
-        }
       }
 
       return allResults
@@ -310,74 +249,39 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
       const batchSize = 2000
       const allResults: any[] = []
 
       for (let i = 0; i < sourceNumbers.length; i += batchSize) {
         const batch = sourceNumbers.slice(i, i + batchSize)
+        const placeholders = this.buildPlaceholders(batch.length, isSqlServer)
 
-        if (this.dbType === 'sqlserver') {
+        const sqlString = `
-          const placeholders = batch.map((_, idx) => `@p${idx}`).join(',')
+          WITH RankedRecords AS (
-          const params: Record<string, { value: string; type: sql.ISqlType }> = {}
-
-          batch.forEach((num, idx) => {
-            params[`p${idx}`] = { value: num, type: sql.NVarChar }
-          })
-
-          const sqlString = `
-            WITH RankedRecords AS (
-              SELECT
-                *,
-                ROW_NUMBER() OVER (
-                  PARTITION BY MaterialCode
-                  ORDER BY CreateDate ASC, SequenceNumber ASC
-                ) AS rn
-              FROM ${tableName}
-              WHERE SourceNumber IN (${placeholders})
-                AND MaterialCode IS NOT NULL
-            )
             SELECT
-              Factory, MaterialStatus, PlanNumber, SourceNumber, MaterialType,
+              *,
-              ProductCode, ProductName, ProductUnit, ProductPlanQuantity,
+              ROW_NUMBER() OVER (
-              UseDepartment, Remark, Creator, CreateDate, Approver, ApproveDate,
+                PARTITION BY MaterialCode
-              SequenceNumber, MaterialCode, MaterialName, Specification, Model,
+                ORDER BY CreateDate ASC, SequenceNumber ASC
-              DrawingNumber, MaterialQuality, PlanQuantity, Unit, RequiredDate,
+              ) AS rn
-              Warehouse, UnitUsage, CumulativeOutputQuantity, BOMVersion
+            FROM ${tableName}
-            FROM RankedRecords
+            WHERE SourceNumber IN (${placeholders})
-            WHERE rn = 1
+              AND MaterialCode IS NOT NULL
-          `
+          )
+          SELECT
+            Factory, MaterialStatus, PlanNumber, SourceNumber, MaterialType,
+            ProductCode, ProductName, ProductUnit, ProductPlanQuantity,
+            UseDepartment, Remark, Creator, CreateDate, Approver, ApproveDate,
+            SequenceNumber, MaterialCode, MaterialName, Specification, Model,
+            DrawingNumber, MaterialQuality, PlanQuantity, Unit, RequiredDate,
+            Warehouse, UnitUsage, CumulativeOutputQuantity, BOMVersion
+          FROM RankedRecords
+          WHERE rn = 1
+        `
 
-          const result = await (dbService as SqlServerService).queryWithParams(sqlString, params)
+        const result = await dbService.query(sqlString, batch)
-          allResults.push(...result.rows)
+        allResults.push(...result.rows)
-        } else {
-          const placeholders = batch.map(() => '?').join(',')
-
-          const sqlString = `
-            WITH RankedRecords AS (
-              SELECT
-                *,
-                ROW_NUMBER() OVER (
-                  PARTITION BY MaterialCode
-                  ORDER BY CreateDate ASC, SequenceNumber ASC
-                ) AS rn
-              FROM ${tableName}
-              WHERE SourceNumber IN (${placeholders})
-                AND MaterialCode IS NOT NULL
-            )
-            SELECT
-              Factory, MaterialStatus, PlanNumber, SourceNumber, MaterialType,
-              ProductCode, ProductName, ProductUnit, ProductPlanQuantity,
-              UseDepartment, Remark, Creator, CreateDate, Approver, ApproveDate,
-              SequenceNumber, MaterialCode, MaterialName, Specification, Model,
-              DrawingNumber, MaterialQuality, PlanQuantity, Unit, RequiredDate,
-              Warehouse, UnitUsage, CumulativeOutputQuantity, BOMVersion
-            FROM RankedRecords
-            WHERE rn = 1
-          `
-
-          const result = await (dbService as MySqlService).query(sqlString, batch)
-          allResults.push(...result.rows)
-        }
       }
 
       return allResults
@@ -398,30 +302,17 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT *
+        SELECT *
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE SourceNumber = @sourceNumber
+        WHERE SourceNumber = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [sourceNumber])
-          sourceNumber: { value: sourceNumber, type: sql.NVarChar }
+      return result.rows
-        })
-
-        return result.rows
-      } else {
-        const sqlString = `
-          SELECT *
-          FROM ${tableName}
-          WHERE SourceNumber = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [sourceNumber])
-
-        return result.rows
-      }
     } catch (error) {
       log.error('Query by source number error', {
         error: error instanceof Error ? error.message : String(error)
@@ -441,30 +332,17 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT *
+        SELECT *
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE PlanNumber = @planNumber
+        WHERE PlanNumber = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [planNumber])
-          planNumber: { value: planNumber, type: sql.NVarChar }
+      return result.rows
-        })
-
-        return result.rows
-      } else {
-        const sqlString = `
-          SELECT *
-          FROM ${tableName}
-          WHERE PlanNumber = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [planNumber])
-
-        return result.rows
-      }
     } catch (error) {
       log.error('Query by plan number error', {
         error: error instanceof Error ? error.message : String(error)
@@ -486,35 +364,17 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
+      const placeholders = this.buildPlaceholders(planNumbers.length, isSqlServer)
 
-      if (this.dbType === 'sqlserver') {
+      const sqlString = `
-        const placeholders = planNumbers.map((_, idx) => `@p${idx}`).join(',')
+        SELECT *
-        const params: Record<string, { value: string; type: sql.ISqlType }> = {}
+        FROM ${tableName}
+        WHERE PlanNumber IN (${placeholders})
+      `
 
-        planNumbers.forEach((num, idx) => {
+      const result = await dbService.query(sqlString, planNumbers)
-          params[`p${idx}`] = { value: num, type: sql.NVarChar }
+      return result.rows
-        })
-
-        const sqlString = `
-          SELECT *
-          FROM ${tableName}
-          WHERE PlanNumber IN (${placeholders})
-        `
-
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, params)
-        return result.rows
-      } else {
-        const placeholders = planNumbers.map(() => '?').join(',')
-
-        const sqlString = `
-          SELECT *
-          FROM ${tableName}
-          WHERE PlanNumber IN (${placeholders})
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, planNumbers)
-        return result.rows
-      }
     } catch (error) {
       log.error('Query by plan numbers error', {
         error: error instanceof Error ? error.message : String(error)
@@ -535,11 +395,7 @@ export class DiscreteMaterialPlanDAO {
       const tableName = this.getTableName()
 
       const sqlString = `SELECT COUNT(*) as count FROM ${tableName}`
-
+      const result = await dbService.query(sqlString)
-      const result =
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
 
       return result.rows.length > 0 ? (result.rows[0].count as number) : 0
     } catch (error) {
@@ -559,30 +415,17 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT COUNT(*) as count
+        SELECT COUNT(*) as count
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE PlanNumber = @planNumber
+        WHERE PlanNumber = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [planNumber])
-          planNumber: { value: planNumber, type: sql.NVarChar }
+      return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-        })
-
-        return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-      } else {
-        const sqlString = `
-          SELECT COUNT(*) as count
-          FROM ${tableName}
-          WHERE PlanNumber = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [planNumber])
-
-        return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-      }
     } catch (error) {
       log.error('Count by plan number error', {
         error: error instanceof Error ? error.message : String(error)
@@ -600,38 +443,20 @@ export class DiscreteMaterialPlanDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
       if (sourceNumbers && sourceNumbers.length > 0) {
-        if (this.dbType === 'sqlserver') {
+        const placeholders = this.buildPlaceholders(sourceNumbers.length, isSqlServer)
-          const placeholders = sourceNumbers.map((_, idx) => `@p${idx}`).join(',')
-          const params: Record<string, { value: string; type: sql.ISqlType }> = {}
 
-          sourceNumbers.forEach((num, idx) => {
+        const sqlString = `
-            params[`p${idx}`] = { value: num, type: sql.NVarChar }
+          SELECT DISTINCT MaterialName
-          })
+          FROM ${tableName}
+          WHERE SourceNumber IN (${placeholders})
+            AND MaterialName IS NOT NULL
+        `
 
-          const sqlString = `
+        const result = await dbService.query(sqlString, sourceNumbers)
-            SELECT DISTINCT MaterialName
+        return result.rows.map((row) => row.MaterialName as string).filter(Boolean)
-            FROM ${tableName}
-            WHERE SourceNumber IN (${placeholders})
-              AND MaterialName IS NOT NULL
-          `
-
-          const result = await (dbService as SqlServerService).queryWithParams(sqlString, params)
-          return result.rows.map((row) => row.MaterialName as string).filter(Boolean)
-        } else {
-          const placeholders = sourceNumbers.map(() => '?').join(',')
-
-          const sqlString = `
-            SELECT DISTINCT MaterialName
-            FROM ${tableName}
-            WHERE SourceNumber IN (${placeholders})
-              AND MaterialName IS NOT NULL
-          `
-
-          const result = await (dbService as MySqlService).query(sqlString, sourceNumbers)
-          return result.rows.map((row) => row.MaterialName as string).filter(Boolean)
-        }
       } else {
         const sqlString = `
           SELECT DISTINCT MaterialName
@@ -639,11 +464,7 @@ export class DiscreteMaterialPlanDAO {
           WHERE MaterialName IS NOT NULL
         `
 
-        const result =
+        const result = await dbService.query(sqlString)
-          this.dbType === 'sqlserver'
-            ? await (dbService as SqlServerService).query(sqlString)
-            : await (dbService as MySqlService).query(sqlString)
-
         return result.rows.map((row) => row.MaterialName as string).filter(Boolean)
       }
     } catch (error) {
@@ -673,11 +494,7 @@ export class DiscreteMaterialPlanDAO {
         FROM ${tableName}
       `
 
-      const result =
+      const result = await dbService.query(sqlString)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return result.rows.length > 0 ? result.rows[0] : {}
     } catch (error) {
       log.error('Get statistics error', {
@@ -691,13 +508,9 @@ export class DiscreteMaterialPlanDAO {
    * Disconnect from database
    */
   async disconnect(): Promise<void> {
-    if (this.mysqlService) {
+    if (this.dbService) {
-      await this.mysqlService.disconnect()
+      await this.dbService.disconnect()
-      this.mysqlService = null
+      this.dbService = null
-    }
-    if (this.sqlServerService) {
-      await this.sqlServerService.disconnect()
-      this.sqlServerService = null
     }
   }
 }

src/main/services/database/index.ts

@@ -0,0 +1,182 @@
+/**
+ * Database Factory
+ *
+ * Creates and manages database service instances based on configuration.
+ * Supports both MySQL and SQL Server databases.
+ */
+
+import { MySqlService } from './mysql'
+import { SqlServerService } from './sql-server'
+import type {
+  IDatabaseService,
+  DatabaseType,
+  MySqlConfig,
+  SqlServerConfig
+} from '../../types/database.types'
+import { createLogger } from '../logger'
+
+const log = createLogger('DatabaseFactory')
+
+/**
+ * Cached database service instances
+ */
+const instances: Map<DatabaseType, IDatabaseService> = new Map()
+
+/**
+ * Get the current database type from environment
+ */
+export function getDatabaseType(): DatabaseType {
+  const dbType = process.env.DB_TYPE?.toLowerCase()
+  if (dbType === 'sqlserver' || dbType === 'mssql') {
+    return 'sqlserver'
+  }
+  return 'mysql'
+}
+
+/**
+ * Create MySQL configuration from environment variables
+ */
+export function createMySqlConfig(): MySqlConfig {
+  return {
+    host: process.env.DB_MYSQL_HOST || 'localhost',
+    port: parseInt(process.env.DB_MYSQL_PORT || '3306', 10),
+    user: process.env.DB_USERNAME || 'root',
+    password: process.env.DB_PASSWORD || '',
+    database: process.env.DB_NAME || ''
+  }
+}
+
+/**
+ * Create SQL Server configuration from environment variables
+ */
+export function createSqlServerConfig(): SqlServerConfig {
+  return {
+    server: process.env.DB_SERVER || 'localhost',
+    port: parseInt(process.env.DB_SQLSERVER_PORT || '1433', 10),
+    user: process.env.DB_USERNAME || 'sa',
+    password: process.env.DB_PASSWORD || '',
+    database: process.env.DB_NAME || '',
+    options: {
+      encrypt: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes',
+      trustServerCertificate: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes'
+    }
+  }
+}
+
+/**
+ * Create a database service instance
+ *
+ * Uses singleton pattern - returns cached instance if available.
+ *
+ * @param type - Optional database type override (defaults to DB_TYPE env var)
+ * @returns Database service instance
+ */
+export async function create(type?: DatabaseType): Promise<IDatabaseService> {
+  const dbType = type || getDatabaseType()
+
+  // Return cached instance if available and connected
+  const cached = instances.get(dbType)
+  if (cached && cached.isConnected()) {
+    log.debug('Returning cached database instance', { type: dbType })
+    return cached
+  }
+
+  // Create new instance
+  let service: IDatabaseService
+
+  if (dbType === 'sqlserver') {
+    log.info('Creating SQL Server database service')
+    service = new SqlServerService(createSqlServerConfig())
+  } else {
+    log.info('Creating MySQL database service')
+    service = new MySqlService(createMySqlConfig())
+  }
+
+  // Connect to database
+  await service.connect()
+  log.info('Database connected', { type: dbType })
+
+  // Cache the instance
+  instances.set(dbType, service)
+
+  return service
+}
+
+/**
+ * Get existing database service without creating new one
+ *
+ * @param type - Optional database type (defaults to DB_TYPE env var)
+ * @returns Database service instance or undefined
+ */
+export function get(type?: DatabaseType): IDatabaseService | undefined {
+  const dbType = type || getDatabaseType()
+  return instances.get(dbType)
+}
+
+/**
+ * Disconnect and remove a specific database service
+ *
+ * @param type - Optional database type (defaults to DB_TYPE env var)
+ */
+export async function disconnect(type?: DatabaseType): Promise<void> {
+  const dbType = type || getDatabaseType()
+  const service = instances.get(dbType)
+
+  if (service) {
+    try {
+      await service.disconnect()
+      log.info('Database disconnected', { type: dbType })
+    } catch (error) {
+      log.warn('Error disconnecting database', {
+        type: dbType,
+        error: error instanceof Error ? error.message : String(error)
+      })
+    }
+    instances.delete(dbType)
+  }
+}
+
+/**
+ * Disconnect all database services
+ */
+export async function disconnectAll(): Promise<void> {
+  log.info('Disconnecting all database services')
+
+  const disconnectPromises = Array.from(instances.entries()).map(async ([type, service]) => {
+    try {
+      await service.disconnect()
+      log.debug('Database disconnected', { type })
+    } catch (error) {
+      log.warn('Error disconnecting database', {
+        type,
+        error: error instanceof Error ? error.message : String(error)
+      })
+    }
+  })
+
+  await Promise.all(disconnectPromises)
+  instances.clear()
+  log.info('All database services disconnected')
+}
+
+/**
+ * Check if a database service is connected
+ *
+ * @param type - Optional database type (defaults to DB_TYPE env var)
+ */
+export function isConnected(type?: DatabaseType): boolean {
+  const dbType = type || getDatabaseType()
+  const service = instances.get(dbType)
+  return service?.isConnected() ?? false
+}
+
+// Re-export types and services
+export { MySqlService } from './mysql'
+export { SqlServerService } from './sql-server'
+export type {
+  IDatabaseService,
+  DatabaseType,
+  QueryResult,
+  MySqlConfig,
+  SqlServerConfig
+} from '../../types/database.types'

src/main/services/database/materials-to-be-deleted-dao.ts

@@ -8,9 +8,7 @@
  * - Statistics gathering
  */
 
-import { MySqlService } from './mysql'
+import { create, type IDatabaseService } from './index'
-import { SqlServerService } from './sql-server'
-import sql from 'mssql'
 import { createLogger } from '../logger'
 
 const log = createLogger('MaterialsToBeDeletedDAO')
@@ -59,70 +57,37 @@ export const MATERIALS_TO_BE_DELETED_CONFIG = {
  * MaterialsToBeDeleted DAO Class
  */
 export class MaterialsToBeDeletedDAO {
-  private mysqlService: MySqlService | null = null
+  private dbService: IDatabaseService | null = null
-  private sqlServerService: SqlServerService | null = null
-  private dbType: 'mysql' | 'sqlserver' = 'mysql'
-
-  /**
-   * Constructor - determine database type from environment
-   */
-  constructor() {
-    const dbType = process.env.DB_TYPE?.toLowerCase()
-    if (dbType === 'sqlserver' || dbType === 'mssql') {
-      this.dbType = 'sqlserver'
-    } else {
-      this.dbType = 'mysql'
-    }
-  }
 
   /**
    * Get the appropriate table name based on database type
    */
   private getTableName(): string {
-    return this.dbType === 'sqlserver'
+    const isSqlServer = this.dbService?.type === 'sqlserver'
+    return isSqlServer
       ? MATERIALS_TO_BE_DELETED_CONFIG.TABLE_NAME_SQLSERVER
       : MATERIALS_TO_BE_DELETED_CONFIG.TABLE_NAME_MYSQL
   }
 
   /**
-   * Get database service instance (MySQL or SQL Server)
+   * Get database service instance using DatabaseFactory
    */
-  private async getDatabaseService(): Promise<MySqlService | SqlServerService> {
+  private async getDatabaseService(): Promise<IDatabaseService> {
-    if (this.dbType === 'sqlserver') {
+    if (this.dbService && this.dbService.isConnected()) {
-      if (this.sqlServerService && this.sqlServerService.isConnected()) {
+      return this.dbService
-        return this.sqlServerService
-      }
-
-      this.sqlServerService = new SqlServerService({
-        server: process.env.DB_SERVER || 'localhost',
-        port: parseInt(process.env.DB_SQLSERVER_PORT || '1433', 10),
-        user: process.env.DB_USERNAME || 'sa',
-        password: process.env.DB_PASSWORD || '',
-        database: process.env.DB_NAME || '',
-        options: {
-          encrypt: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes',
-          trustServerCertificate: process.env.DB_TRUST_SERVER_CERTIFICATE === 'yes'
-        }
-      })
-
-      await this.sqlServerService.connect()
-      return this.sqlServerService
-    } else {
-      if (this.mysqlService && this.mysqlService.isConnected()) {
-        return this.mysqlService
-      }
-
-      this.mysqlService = new MySqlService({
-        host: process.env.DB_MYSQL_HOST || 'localhost',
-        port: parseInt(process.env.DB_MYSQL_PORT || '3306', 10),
-        user: process.env.DB_USERNAME || 'root',
-        password: process.env.DB_PASSWORD || '',
-        database: process.env.DB_NAME || ''
-      })
-
-      await this.mysqlService.connect()
-      return this.mysqlService
     }
+
+    this.dbService = await create()
+    return this.dbService
+  }
+
+  /**
+   * Build placeholders for IN clause based on database type
+   */
+  private buildPlaceholders(count: number, isSqlServer: boolean): string {
+    return isSqlServer
+      ? Array.from({ length: count }, (_, idx) => `@p${idx}`).join(',')
+      : Array.from({ length: count }, () => '?').join(',')
   }
 
   // ==================== UPSERT (MERGE) ====================
@@ -144,28 +109,28 @@ export class MaterialsToBeDeletedDAO {
       const tableName = this.getTableName()
       const code = materialCode.trim()
       const manager = managerName?.trim() || null
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      if (isSqlServer) {
+        // SQL Server MERGE statement
         const sqlString = `
           MERGE ${tableName} AS target
-          USING (VALUES (@materialCode, @managerName)) AS source (MaterialCode, ManagerName)
+          USING (VALUES (@p0, @p1)) AS source (MaterialCode, ManagerName)
           ON target.MaterialCode = source.MaterialCode
           WHEN MATCHED THEN UPDATE SET ManagerName = source.ManagerName
           WHEN NOT MATCHED THEN INSERT (MaterialCode, ManagerName) VALUES (source.MaterialCode, source.ManagerName);
         `
 
-        await (dbService as SqlServerService).queryWithParams(sqlString, {
+        await dbService.query(sqlString, [code, manager])
-          materialCode: { value: code, type: sql.NVarChar },
-          managerName: { value: manager, type: sql.NVarChar }
-        })
       } else {
+        // MySQL ON DUPLICATE KEY UPDATE
         const sqlString = `
           INSERT INTO ${tableName} (MaterialCode, ManagerName)
           VALUES (?, ?)
           ON DUPLICATE KEY UPDATE ManagerName = VALUES(ManagerName)
         `
 
-        await (dbService as MySqlService).query(sqlString, [code, manager])
+        await dbService.query(sqlString, [code, manager])
       }
 
       return true
@@ -198,6 +163,7 @@ export class MaterialsToBeDeletedDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
       for (const material of materials) {
         const materialCode = material.materialCode?.trim()
@@ -209,27 +175,26 @@ export class MaterialsToBeDeletedDAO {
         }
 
         try {
-          if (this.dbType === 'sqlserver') {
+          if (isSqlServer) {
+            // SQL Server MERGE statement
             const sqlString = `
               MERGE ${tableName} AS target
-              USING (VALUES (@materialCode, @managerName)) AS source (MaterialCode, ManagerName)
+              USING (VALUES (@p0, @p1)) AS source (MaterialCode, ManagerName)
               ON target.MaterialCode = source.MaterialCode
               WHEN MATCHED THEN UPDATE SET ManagerName = source.ManagerName
               WHEN NOT MATCHED THEN INSERT (MaterialCode, ManagerName) VALUES (source.MaterialCode, source.ManagerName);
             `
 
-            await (dbService as SqlServerService).queryWithParams(sqlString, {
+            await dbService.query(sqlString, [materialCode, managerName || null])
-              materialCode: { value: materialCode, type: sql.NVarChar },
-              managerName: { value: managerName || null, type: sql.NVarChar }
-            })
           } else {
+            // MySQL ON DUPLICATE KEY UPDATE
             const sqlString = `
               INSERT INTO ${tableName} (MaterialCode, ManagerName)
               VALUES (?, ?)
               ON DUPLICATE KEY UPDATE ManagerName = VALUES(ManagerName)
             `
 
-            await (dbService as MySqlService).query(sqlString, [materialCode, managerName || null])
+            await dbService.query(sqlString, [materialCode, managerName || null])
           }
 
           stats.success++
@@ -268,11 +233,7 @@ export class MaterialsToBeDeletedDAO {
         WHERE MaterialCode IS NOT NULL
       `
 
-      const result =
+      const result = await dbService.query(sqlString)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return new Set(result.rows.map((row) => row.MaterialCode as string).filter(Boolean))
     } catch (error) {
       log.error('Get all material codes error', {
@@ -298,11 +259,7 @@ export class MaterialsToBeDeletedDAO {
         ORDER BY ManagerName, MaterialCode
       `
 
-      const result =
+      const result = await dbService.query(sqlString)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return result.rows.map((row) => ({
         id: row.ID as number,
         materialCode: row.MaterialCode as string,
@@ -325,40 +282,22 @@ export class MaterialsToBeDeletedDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT ID, MaterialCode, ManagerName
+        SELECT ID, MaterialCode, ManagerName
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE ManagerName = @managerName AND MaterialCode IS NOT NULL
+        WHERE ManagerName = ${placeholder} AND MaterialCode IS NOT NULL
-          ORDER BY MaterialCode
+        ORDER BY MaterialCode
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [managerName])
-          managerName: { value: managerName, type: sql.NVarChar }
+      return result.rows.map((row) => ({
-        })
+        id: row.ID as number,
-
+        materialCode: row.MaterialCode as string,
-        return result.rows.map((row) => ({
+        managerName: row.ManagerName as string
-          id: row.ID as number,
+      }))
-          materialCode: row.MaterialCode as string,
-          managerName: row.ManagerName as string
-        }))
-      } else {
-        const sqlString = `
-          SELECT ID, MaterialCode, ManagerName
-          FROM ${tableName}
-          WHERE ManagerName = ? AND MaterialCode IS NOT NULL
-          ORDER BY MaterialCode
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [managerName])
-
-        return result.rows.map((row) => ({
-          id: row.ID as number,
-          materialCode: row.MaterialCode as string,
-          managerName: row.ManagerName as string
-        }))
-      }
     } catch (error) {
       log.error('Get materials by manager error', {
         error: error instanceof Error ? error.message : String(error)
@@ -383,11 +322,7 @@ export class MaterialsToBeDeletedDAO {
         ORDER BY ManagerName
       `
 
-      const result =
+      const result = await dbService.query(sqlString)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return result.rows.map((row) => row.ManagerName as string).filter(Boolean)
     } catch (error) {
       log.error('Get managers error', {
@@ -407,47 +342,26 @@ export class MaterialsToBeDeletedDAO {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
       const code = materialCode.trim()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT ID, MaterialCode, ManagerName
+        SELECT ID, MaterialCode, ManagerName
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE MaterialCode = @materialCode
+        WHERE MaterialCode = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [code])
-          materialCode: { value: code, type: sql.NVarChar }
-        })
 
-        if (result.rows.length === 0) {
+      if (result.rows.length === 0) {
-          return null
+        return null
-        }
+      }
 
-        const row = result.rows[0]
+      const row = result.rows[0]
-        return {
+      return {
-          id: row.ID as number,
+        id: row.ID as number,
-          materialCode: row.MaterialCode as string,
+        materialCode: row.MaterialCode as string,
-          managerName: row.ManagerName as string
+        managerName: row.ManagerName as string
-        }
-      } else {
-        const sqlString = `
-          SELECT ID, MaterialCode, ManagerName
-          FROM ${tableName}
-          WHERE MaterialCode = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [code])
-
-        if (result.rows.length === 0) {
-          return null
-        }
-
-        const row = result.rows[0]
-        return {
-          id: row.ID as number,
-          materialCode: row.MaterialCode as string,
-          managerName: row.ManagerName as string
-        }
       }
     } catch (error) {
       log.error('Get record by material code error', {
@@ -469,28 +383,16 @@ export class MaterialsToBeDeletedDAO {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
       const code = materialCode.trim()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          DELETE FROM ${tableName}
+        DELETE FROM ${tableName}
-          WHERE MaterialCode = @materialCode
+        WHERE MaterialCode = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [code])
-          materialCode: { value: code, type: sql.NVarChar }
+      return result.rowCount > 0
-        })
-
-        return result.rowCount > 0
-      } else {
-        const sqlString = `
-          DELETE FROM ${tableName}
-          WHERE MaterialCode = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [code])
-
-        return result.rowCount > 0
-      }
     } catch (error) {
       log.error('Delete by material code error', {
         error: error instanceof Error ? error.message : String(error)
@@ -508,28 +410,16 @@ export class MaterialsToBeDeletedDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          DELETE FROM ${tableName}
+        DELETE FROM ${tableName}
-          WHERE ManagerName = @managerName
+        WHERE ManagerName = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [managerName])
-          managerName: { value: managerName, type: sql.NVarChar }
+      return result.rowCount
-        })
-
-        return result.rowCount
-      } else {
-        const sqlString = `
-          DELETE FROM ${tableName}
-          WHERE ManagerName = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [managerName])
-
-        return result.rowCount
-      }
     } catch (error) {
       log.error('Delete by manager error', {
         error: error instanceof Error ? error.message : String(error)
@@ -548,12 +438,7 @@ export class MaterialsToBeDeletedDAO {
       const tableName = this.getTableName()
 
       const sqlString = `DELETE FROM ${tableName}`
-
+      const result = await dbService.query(sqlString)
-      const result =
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
-
       return result.rowCount
     } catch (error) {
       log.error('Delete all materials error', {
@@ -579,36 +464,22 @@ export class MaterialsToBeDeletedDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
       for (let i = 0; i < materialCodes.length; i += batchSize) {
         const batch = materialCodes.slice(i, i + batchSize)
+        const placeholders = this.buildPlaceholders(batch.length, isSqlServer)
 
-        if (this.dbType === 'sqlserver') {
+        const sqlString = `
-          const placeholders = batch.map((_, idx) => `@p${idx}`).join(',')
+          DELETE FROM ${tableName}
-          const params: Record<string, { value: string; type: sql.ISqlType }> = {}
+          WHERE MaterialCode IN (${placeholders})
+        `
 
-          batch.forEach((code, idx) => {
+        const result = await dbService.query(
-            params[`p${idx}`] = { value: code.trim(), type: sql.NVarChar }
+          sqlString,
-          })
+          batch.map((c) => c.trim())
-
+        )
-          const sqlString = `
+        totalDeleted += result.rowCount
-            DELETE FROM ${tableName}
-            WHERE MaterialCode IN (${placeholders})
-          `
-
-          const result = await (dbService as SqlServerService).queryWithParams(sqlString, params)
-          totalDeleted += result.rowCount
-        } else {
-          const placeholders = batch.map(() => '?').join(',')
-
-          const sqlString = `
-            DELETE FROM ${tableName}
-            WHERE MaterialCode IN (${placeholders})
-          `
-
-          const result = await (dbService as MySqlService).query(sqlString, batch)
-          totalDeleted += result.rowCount
-        }
       }
     } catch (error) {
       log.error('Delete by material codes error', {
@@ -631,30 +502,17 @@ export class MaterialsToBeDeletedDAO {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
       const code = materialCode.trim()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT COUNT(*) as count
+        SELECT COUNT(*) as count
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE MaterialCode = @materialCode
+        WHERE MaterialCode = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [code])
-          materialCode: { value: code, type: sql.NVarChar }
+      return result.rows.length > 0 && (result.rows[0].count as number) > 0
-        })
-
-        return result.rows.length > 0 && (result.rows[0].count as number) > 0
-      } else {
-        const sqlString = `
-          SELECT COUNT(*) as count
-          FROM ${tableName}
-          WHERE MaterialCode = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [code])
-
-        return result.rows.length > 0 && (result.rows[0].count as number) > 0
-      }
     } catch (error) {
       log.error('Material exists error', {
         error: error instanceof Error ? error.message : String(error)
@@ -673,11 +531,7 @@ export class MaterialsToBeDeletedDAO {
       const tableName = this.getTableName()
 
       const sqlString = `SELECT COUNT(*) as count FROM ${tableName}`
-
+      const result = await dbService.query(sqlString)
-      const result =
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(sqlString)
-          : await (dbService as MySqlService).query(sqlString)
 
       return result.rows.length > 0 ? (result.rows[0].count as number) : 0
     } catch (error) {
@@ -697,30 +551,17 @@ export class MaterialsToBeDeletedDAO {
     try {
       const dbService = await this.getDatabaseService()
       const tableName = this.getTableName()
+      const isSqlServer = dbService.type === 'sqlserver'
 
-      if (this.dbType === 'sqlserver') {
+      const placeholder = isSqlServer ? '@p0' : '?'
-        const sqlString = `
+      const sqlString = `
-          SELECT COUNT(*) as count
+        SELECT COUNT(*) as count
-          FROM ${tableName}
+        FROM ${tableName}
-          WHERE ManagerName = @managerName
+        WHERE ManagerName = ${placeholder}
-        `
+      `
 
-        const result = await (dbService as SqlServerService).queryWithParams(sqlString, {
+      const result = await dbService.query(sqlString, [managerName])
-          managerName: { value: managerName, type: sql.NVarChar }
+      return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-        })
-
-        return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-      } else {
-        const sqlString = `
-          SELECT COUNT(*) as count
-          FROM ${tableName}
-          WHERE ManagerName = ?
-        `
-
-        const result = await (dbService as MySqlService).query(sqlString, [managerName])
-
-        return result.rows.length > 0 ? (result.rows[0].count as number) : 0
-      }
     } catch (error) {
       log.error('Count by manager error', {
         error: error instanceof Error ? error.message : String(error)
@@ -747,11 +588,7 @@ export class MaterialsToBeDeletedDAO {
         WHERE MaterialCode IS NOT NULL
       `
 
-      const statsResult =
+      const statsResult = await dbService.query(statsSql)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(statsSql)
-          : await (dbService as MySqlService).query(statsSql)
-
       const stats = statsResult.rows[0] || {}
 
       // Get materials per manager
@@ -763,11 +600,7 @@ export class MaterialsToBeDeletedDAO {
         ORDER BY count DESC
       `
 
-      const managerResult =
+      const managerResult = await dbService.query(managerSql)
-        this.dbType === 'sqlserver'
-          ? await (dbService as SqlServerService).query(managerSql)
-          : await (dbService as MySqlService).query(managerSql)
-
       const materialsPerManager = managerResult.rows.map((row) => ({
         [row.ManagerName as string]: row.count as number
       }))
@@ -793,13 +626,9 @@ export class MaterialsToBeDeletedDAO {
    * Disconnect from database
    */
   async disconnect(): Promise<void> {
-    if (this.mysqlService) {
+    if (this.dbService) {
-      await this.mysqlService.disconnect()
+      await this.dbService.disconnect()
-      this.mysqlService = null
+      this.dbService = null
-    }
-    if (this.sqlServerService) {
-      await this.sqlServerService.disconnect()
-      this.sqlServerService = null
     }
   }
 }

src/main/services/database/mysql.ts

@@ -1,20 +1,17 @@
 import mysql from 'mysql2/promise'
+import type {
+  IDatabaseService,
+  DatabaseType,
+  QueryResult,
+  MySqlConfig
+} from '../../types/database.types'
 
-export interface MySqlConfig {
+export type { MySqlConfig } from '../../types/database.types'
-  host: string
-  port: number
-  user: string
-  password: string
-  database: string
-}
 
-export interface MySqlQueryResult {
+export class MySqlService implements IDatabaseService {
-  rows: Record<string, unknown>[]
+  /** Database type identifier */
-  columns: string[]
+  readonly type: DatabaseType = 'mysql'
-  rowCount: number
-}
 
-export class MySqlService {
   private connection: mysql.Connection | null = null
   private config: MySqlConfig
 
@@ -72,7 +69,7 @@ export class MySqlService {
   /**
    * Execute a query and return results
    */
-  async query(sql: string, params?: any[]): Promise<MySqlQueryResult> {
+  async query(sql: string, params?: any[]): Promise<QueryResult> {
     if (!this.connection) {
       throw new Error('Not connected to MySQL. Call connect() first.')
     }

src/main/services/database/sql-server.ts

@@ -1,24 +1,17 @@
 import sql from 'mssql'
+import type {
+  IDatabaseService,
+  DatabaseType,
+  QueryResult,
+  SqlServerConfig
+} from '../../types/database.types'
 
-export interface SqlServerConfig {
+export type { SqlServerConfig } from '../../types/database.types'
-  server: string
-  port: number
-  user: string
-  password: string
-  database: string
-  options?: {
-    encrypt?: boolean
-    trustServerCertificate?: boolean
-  }
-}
 
-export interface SqlServerQueryResult {
+export class SqlServerService implements IDatabaseService {
-  rows: Record<string, unknown>[]
+  /** Database type identifier */
-  columns: string[]
+  readonly type: DatabaseType = 'sqlserver'
-  rowCount: number
-}
 
-export class SqlServerService {
   private pool: sql.ConnectionPool | null = null
   private config: SqlServerConfig
 
@@ -79,8 +72,10 @@ export class SqlServerService {
 
   /**
    * Execute a query and return results
+   * @param sqlString - SQL query string with @p0, @p1, ... placeholders
+   * @param params - Query parameters as an array (converted to @p0, @p1, ...)
    */
-  async query(sqlString: string, params?: Record<string, unknown>): Promise<SqlServerQueryResult> {
+  async query(sqlString: string, params?: any[]): Promise<QueryResult> {
     if (!this.pool) {
       throw new Error('Not connected to SQL Server. Call connect() first.')
     }
@@ -88,11 +83,11 @@ export class SqlServerService {
     try {
       const request = this.pool.request()
 
-      // Add parameters if provided
+      // Add parameters if provided - convert array to @p0, @p1, ... format
-      if (params) {
+      if (params && params.length > 0) {
-        for (const [key, value] of Object.entries(params)) {
+        params.forEach((value, index) => {
-          request.input(key, value)
+          request.input(`p${index}`, value)
-        }
+        })
       }
 
       const result = await request.query(sqlString)
@@ -113,12 +108,14 @@ export class SqlServerService {
   }
 
   /**
-   * Execute a prepared statement with parameters
+   * Execute a prepared statement with named parameters
+   * @param sqlString - SQL query string with @paramName placeholders
+   * @param params - Parameters as an object with { value, type? } structure
    */
   async queryWithParams(
     sqlString: string,
     params: Record<string, { value: unknown; type?: sql.ISqlType }>
-  ): Promise<SqlServerQueryResult> {
+  ): Promise<QueryResult> {
     if (!this.pool) {
       throw new Error('Not connected to SQL Server. Call connect() first.')
     }
@@ -154,8 +151,9 @@ export class SqlServerService {
 
   /**
    * Execute multiple queries in a transaction
+   * @param queries - Array of queries with array-based parameters
    */
-  async transaction(queries: { sql: string; params?: Record<string, unknown> }[]): Promise<void> {
+  async transaction(queries: { sql: string; params?: any[] }[]): Promise<void> {
     if (!this.pool) {
       throw new Error('Not connected to SQL Server. Call connect() first.')
     }
@@ -168,10 +166,11 @@ export class SqlServerService {
       for (const { sql: sqlString, params } of queries) {
         const request = new sql.Request(transaction)
 
-        if (params) {
+        // Add parameters if provided - convert array to @p0, @p1, ... format
-          for (const [key, value] of Object.entries(params)) {
+        if (params && params.length > 0) {
-            request.input(key, value)
+          params.forEach((value, index) => {
-          }
+            request.input(`p${index}`, value)
+          })
         }
 
         await request.query(sqlString)

src/main/services/erp/order-resolver.ts

@@ -2,7 +2,7 @@
  * Order Number Resolver Service
  *
  * Automatically recognizes productionID and 生产订单号 (production order number),
- * and converts them via MySQL database lookup.
+ * and converts them via database lookup.
  *
  * - productionID format: 2 digits + 1 letter + serial number (e.g., "22A1", "22A1234")
  * - 生产订单号 format: SC + 14 digits (e.g., "SC70202602120085")
@@ -11,7 +11,7 @@
  * Fields: 总排号 (productionID), 生产订单号 (production order number)
  */
 
-import { MySqlService } from '../database/mysql'
+import type { IDatabaseService } from '../database'
 
 /**
  * Order mapping result
@@ -71,10 +71,10 @@ export const DB_CONFIG = {
  * Order Number Resolver Service
  */
 export class OrderNumberResolver {
-  private mysqlService: MySqlService
+  private dbService: IDatabaseService
 
-  constructor(mysqlService: MySqlService) {
+  constructor(dbService: IDatabaseService) {
-    this.mysqlService = mysqlService
+    this.dbService = dbService
   }
 
   /**
@@ -202,7 +202,7 @@ export class OrderNumberResolver {
   private async resolveProductionIds(productionIds: string[]): Promise<OrderMapping[]> {
     const mappings: OrderMapping[] = []
 
-    if (!this.mysqlService.isConnected()) {
+    if (!this.dbService.isConnected()) {
       // Database not connected, return all as failed
       for (const pid of productionIds) {
         mappings.push({
@@ -217,15 +217,21 @@ export class OrderNumberResolver {
     }
 
     try {
-      // Build query with placeholders
+      // Build query - use different placeholder style based on database type
-      const placeholders = productionIds.map(() => '?').join(', ')
+      const isSqlServer = this.dbService.type === 'sqlserver'
+      const placeholders = isSqlServer
+        ? productionIds.map((_, idx) => `@p${idx}`).join(', ')
+        : productionIds.map(() => '?').join(', ')
+
+      // Use appropriate quoting for table/field names
+      const quote = isSqlServer ? '' : '`'
       const query = `
-        SELECT \`${DB_CONFIG.FIELD_PRODUCTION_ID}\`, \`${DB_CONFIG.FIELD_ORDER_NUMBER}\`
+        SELECT ${quote}${DB_CONFIG.FIELD_PRODUCTION_ID}${quote}, ${quote}${DB_CONFIG.FIELD_ORDER_NUMBER}${quote}
-        FROM \`${DB_CONFIG.TABLE_NAME}\`
+        FROM ${quote}${DB_CONFIG.TABLE_NAME}${quote}
-        WHERE \`${DB_CONFIG.FIELD_PRODUCTION_ID}\` IN (${placeholders})
+        WHERE ${quote}${DB_CONFIG.FIELD_PRODUCTION_ID}${quote} IN (${placeholders})
       `
 
-      const result = await this.mysqlService.query(query, productionIds)
+      const result = await this.dbService.query(query, productionIds)
 
       // Create a map for quick lookup
       const resultMap = new Map<string, string>()
@@ -281,19 +287,26 @@ export class OrderNumberResolver {
    * @returns List of valid order numbers
    */
   private async verifyOrderNumbers(orderNumbers: string[]): Promise<string[]> {
-    if (!this.mysqlService.isConnected()) {
+    if (!this.dbService.isConnected()) {
       return orderNumbers // Skip verification if not connected
     }
 
     try {
-      const placeholders = orderNumbers.map(() => '?').join(', ')
+      // Build query - use different placeholder style based on database type
+      const isSqlServer = this.dbService.type === 'sqlserver'
+      const placeholders = isSqlServer
+        ? orderNumbers.map((_, idx) => `@p${idx}`).join(', ')
+        : orderNumbers.map(() => '?').join(', ')
+
+      // Use appropriate quoting for table/field names
+      const quote = isSqlServer ? '' : '`'
       const query = `
-        SELECT \`${DB_CONFIG.FIELD_ORDER_NUMBER}\`
+        SELECT ${quote}${DB_CONFIG.FIELD_ORDER_NUMBER}${quote}
-        FROM \`${DB_CONFIG.TABLE_NAME}\`
+        FROM ${quote}${DB_CONFIG.TABLE_NAME}${quote}
-        WHERE \`${DB_CONFIG.FIELD_ORDER_NUMBER}\` IN (${placeholders})
+        WHERE ${quote}${DB_CONFIG.FIELD_ORDER_NUMBER}${quote} IN (${placeholders})
       `
 
-      const result = await this.mysqlService.query(query, orderNumbers)
+      const result = await this.dbService.query(query, orderNumbers)
       return result.rows.map((row) => row[DB_CONFIG.FIELD_ORDER_NUMBER] as string)
     } catch (error) {
       console.warn('[OrderResolver] Failed to verify order numbers:', error)

src/main/types/database.types.ts

@@ -0,0 +1,104 @@
+/**
+ * Database Type Definitions
+ *
+ * Provides abstract interfaces for database operations,
+ * supporting both MySQL and SQL Server databases.
+ */
+
+/**
+ * Supported database types
+ */
+export type DatabaseType = 'mysql' | 'sqlserver'
+
+/**
+ * Standard query result interface
+ */
+export interface QueryResult {
+  /** Query result rows */
+  rows: Record<string, unknown>[]
+  /** Column names from the query */
+  columns: string[]
+  /** Number of rows affected or returned */
+  rowCount: number
+}
+
+/**
+ * Database service interface
+ *
+ * Defines the common interface that all database services must implement.
+ * This allows for database-agnostic operations throughout the application.
+ */
+export interface IDatabaseService {
+  /** Database type identifier */
+  readonly type: DatabaseType
+
+  /**
+   * Connect to the database
+   */
+  connect(): Promise<void>
+
+  /**
+   * Disconnect from the database
+   */
+  disconnect(): Promise<void>
+
+  /**
+   * Check if connected to the database
+   */
+  isConnected(): boolean
+
+  /**
+   * Execute a query and return results
+   * @param sql - SQL query string
+   * @param params - Query parameters as an array
+   */
+  query(sql: string, params?: any[]): Promise<QueryResult>
+
+  /**
+   * Execute multiple queries in a transaction
+   * @param queries - Array of queries with optional parameters
+   */
+  transaction(queries: { sql: string; params?: any[] }[]): Promise<void>
+}
+
+/**
+ * Base database configuration interface
+ */
+export interface DatabaseConfig {
+  /** Database server host */
+  host?: string
+  /** Database server port */
+  port?: number
+  /** Database username */
+  user?: string
+  /** Database password */
+  password?: string
+  /** Database name */
+  database?: string
+}
+
+/**
+ * MySQL-specific configuration
+ */
+export interface MySqlConfig extends DatabaseConfig {
+  host: string
+  port: number
+  user: string
+  password: string
+  database: string
+}
+
+/**
+ * SQL Server-specific configuration
+ */
+export interface SqlServerConfig extends DatabaseConfig {
+  server: string
+  port: number
+  user: string
+  password: string
+  database: string
+  options?: {
+    encrypt?: boolean
+    trustServerCertificate?: boolean
+  }
+}