caac411e17
This commit implements multi-database support, allowing the system to switch
between SQL Server and MySQL databases seamlessly.
## New Features
- Database type selection (SQL Server or MySQL) via configuration
- Automatic table name conversion between formats ([dbo].[table] → dbo_table)
- Automatic parameter placeholder handling (? for SQL Server, %s for MySQL)
- GUI settings tab now includes database type dropdown and MySQL configuration
## Database Abstraction Layer
- db/base_connection.py: Abstract base class for database connections
- db/sqlserver_connection.py: SQL Server implementation
- db/mysql_connection.py: MySQL implementation using mysql-connector-python
- db/connection_factory.py: Factory pattern for creating connections
- db/table_name_converter.py: Table name format conversion utility
## DAO Base Class
- db/base_dao.py: Base DAO with helper methods for SQL conversion and placeholders
## Updated Components
- config/schema.py: Extended with DatabaseType enum and MySQL/SQLServer config classes
- config/defaults.py: Added MySQL default configuration
- config/loader.py: Updated to handle new database structure
- db/connection.py: Refactored to use factory pattern and load user config
- All DAO files: Updated to inherit from BaseDAO with automatic conversion
## Dependencies
- Added mysql-connector-python>=8.0.0 to requirements.txt
## Configuration
To use MySQL, set db_type to "mysql" in config/user_settings.json:
{
"database": {
"db_type": "mysql",
"mysql": {
"host": "192.168.31.83",
"port": 3306,
"database": "BLD_DB",
"username": "remote_user",
"password": "3.1415926Beeke"
}
}
}
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
101 lines
2.7 KiB
Python
101 lines
2.7 KiB
Python
"""
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DAO 基类
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提供数据访问对象的通用方法和辅助函数
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"""
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from typing import Optional
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from config.schema import DatabaseType
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from db.base_connection import BaseDatabaseConnection
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from db.connection import get_connection
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from db.table_name_converter import TableNameConverter
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class BaseDAO:
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"""数据访问对象基类"""
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def __init__(self):
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"""初始化 DAO"""
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self.db: Optional[BaseDatabaseConnection] = None
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# 从配置文件加载数据库类型
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from config.loader import ConfigLoader
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app_config = ConfigLoader.load()
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self._db_type = app_config.database.db_type
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def __enter__(self):
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"""进入上下文管理器，建立数据库连接"""
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self.db = get_connection()
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self.db.connect()
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return self
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def __exit__(self, exc_type, exc_val, exc_tb):
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"""退出上下文管理器，关闭数据库连接"""
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if self.db:
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self.db.disconnect()
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def close(self):
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"""关闭数据库连接"""
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if self.db:
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self.db.disconnect()
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def _convert_sql(self, sql: str) -> str:
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"""
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根据当前数据库类型转换 SQL 语句中的表名
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Args:
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sql: 原始 SQL 语句（SQL Server 格式）
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Returns:
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转换后的 SQL 语句
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"""
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if self._db_type == DatabaseType.MYSQL:
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# SQL Server → MySQL
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return TableNameConverter.convert_sql(sql, 'mysql')
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return sql
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def _get_placeholder(self) -> str:
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"""
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获取当前数据库类型的参数占位符
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Returns:
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SQL Server 返回 "?"，MySQL 返回 "%s"
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"""
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if self._db_type == DatabaseType.MYSQL:
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return "%s"
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return "?"
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def _build_placeholders(self, count: int) -> str:
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"""
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构建参数占位符字符串
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Args:
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count: 占位符数量
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Returns:
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占位符字符串，如 "?, ?, ?" 或 "%s, %s, %s"
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"""
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placeholder = self._get_placeholder()
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return ", ".join([placeholder for _ in range(count)])
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def _build_in_clause_placeholders(self, count: int) -> str:
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"""
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构建 IN 子句的参数占位符字符串
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Args:
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count: 占位符数量
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Returns:
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IN 子句占位符字符串，如 "?, ?, ?" 或 "%s, %s, %s"
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"""
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placeholder = self._get_placeholder()
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return ", ".join([placeholder for _ in range(count)])
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def _get_connection(self):
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"""
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获取数据库连接
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Returns:
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数据库连接对象
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"""
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return get_connection()
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