feat(db): add SqlDialect interface and PostgreSQL type definitions

- Add 'postgresql' to DatabaseType union in database.types.ts
- Add PostgreSqlConfig interface extending DatabaseConfig
- Add postgresqlConfigSchema Zod schema with host, port, database,
  username, password, and maxPoolSize fields
- Add 'postgresql' to databaseConfigSchema and type exports
- Create SqlDialect interface with methods for quoteTableName,
  param, params, currentTimestamp, upsert, paginate, maxBatchRows

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main/types/config.schema.ts

@@ -12,7 +12,7 @@ import { z } from 'zod'
 /**
  * 数据库类型枚举
  */
-export const databaseTypeSchema = z.enum(['mysql', 'sqlserver'])
+export const databaseTypeSchema = z.enum(['mysql', 'sqlserver', 'postgresql'])
 export type DatabaseType = z.infer<typeof databaseTypeSchema>
 
 /**
@@ -57,13 +57,27 @@ export const sqlServerConfigSchema = z.object({
   trustServerCertificate: z.boolean().default(true)
 })
 
+/**
+ * PostgreSQL 配置 Schema
+ */
+export const postgresqlConfigSchema = z.object({
+  host: z.string().min(1, 'PostgreSQL host is required'),
+  port: z.number().int().min(1).max(65535).default(5432),
+  database: z.string().min(1, 'PostgreSQL database is required'),
+  username: z.string().min(1, 'PostgreSQL username is required'),
+  password: z.string(),
+  maxPoolSize: z.number().int().min(1).max(100).default(10)
+})
+export type PostgreSqlConfigSchema = z.infer<typeof postgresqlConfigSchema>
+
 /**
  * 数据库配置（包含两种数据库的完整配置）
  */
 export const databaseConfigSchema = z.object({
   activeType: databaseTypeSchema.default('mysql'),
   mysql: mysqlConfigSchema,
-  sqlserver: sqlServerConfigSchema
+  sqlserver: sqlServerConfigSchema,
+  postgresql: postgresqlConfigSchema
 })
 
 /**
@@ -199,6 +213,7 @@ export type FullConfig = z.infer<typeof fullConfigSchema>
 export type DatabaseConfig = z.infer<typeof databaseConfigSchema>
 export type MySqlConfig = z.infer<typeof mysqlConfigSchema>
 export type SqlServerConfig = z.infer<typeof sqlServerConfigSchema>
+export type PostgreSqlConfig = z.infer<typeof postgresqlConfigSchema>
 export type ErpSystemConfig = z.infer<typeof erpSystemConfigSchema>
 export type LoggingConfig = z.infer<typeof loggingConfigSchema>
 export type RustfsConfig = z.infer<typeof rustfsConfigSchema>

src/main/types/database.types.ts

@@ -8,7 +8,7 @@
 /**
  * Supported database types
  */
-export type DatabaseType = 'mysql' | 'sqlserver'
+export type DatabaseType = 'mysql' | 'sqlserver' | 'postgresql'
 
 /**
  * Standard query result interface
@@ -102,3 +102,15 @@ export interface SqlServerConfig extends DatabaseConfig {
     trustServerCertificate?: boolean
   }
 }
+
+/**
+ * PostgreSQL-specific configuration
+ */
+export interface PostgreSqlConfig extends DatabaseConfig {
+  host: string
+  port: number
+  user: string
+  password: string
+  database: string
+  maxPoolSize?: number
+}

src/main/types/sql-dialect.types.ts

@@ -0,0 +1,80 @@
+/**
+ * SQL Dialect Abstraction
+ *
+ * Provides a unified interface for database-specific SQL syntax differences.
+ * Each database type implements this interface to encapsulate:
+ * - Parameter placeholder format
+ * - Table name quoting
+ * - UPSERT syntax
+ * - Pagination syntax
+ * - Current timestamp function
+ * - Batch size limits
+ */
+
+import type { DatabaseType } from './database.types'
+
+export interface SqlDialect {
+  /** Database type identifier */
+  readonly dbType: DatabaseType
+
+  /**
+   * Quote a table name with schema prefix
+   * MySQL: dbo_TableName
+   * SQL Server: [dbo].[TableName]
+   * PostgreSQL: "dbo"."TableName"
+   */
+  quoteTableName(schema: string, table: string): string
+
+  /**
+   * Get placeholder for parameter at given index (0-based)
+   * MySQL: ?
+   * SQL Server: @p0
+   * PostgreSQL: $1
+   */
+  param(index: number): string
+
+  /**
+   * Get comma-separated placeholders for count parameters
+   */
+  params(count: number): string
+
+  /**
+   * Get current timestamp SQL function
+   * MySQL: NOW()
+   * SQL Server: GETDATE()
+   * PostgreSQL: CURRENT_TIMESTAMP
+   */
+  currentTimestamp(): string
+
+  /**
+   * Generate UPSERT SQL for a single row
+   * MySQL: INSERT ... ON DUPLICATE KEY UPDATE
+   * SQL Server: MERGE ... USING ...
+   * PostgreSQL: INSERT ... ON CONFLICT ... DO UPDATE SET
+   */
+  upsert(params: {
+    table: string
+    keyColumns: string[]
+    allColumns: string[]
+    startParamIndex: number
+  }): { sql: string; nextParamIndex: number }
+
+  /**
+   * Append pagination clause to SQL
+   * MySQL/PostgreSQL: LIMIT x OFFSET y
+   * SQL Server: OFFSET x ROWS FETCH NEXT y ROWS ONLY
+   */
+  paginate(params: {
+    sql: string
+    limit: number
+    offset?: number
+    paramIndex: number
+  }): { sql: string; nextParamIndex: number }
+
+  /**
+   * Maximum rows per batch given columns per row
+   * SQL Server: ~71 (due to 2100 param limit)
+   * MySQL/PostgreSQL: 1000
+   */
+  maxBatchRows(columnsPerRow: number): number
+}