MySQL MCP Server

Instructions

Implementation Reference

• src/index.ts:320-370 (handler)

  The main handler function for the insert_data tool. It validates the input arguments and ensures the query is an INSERT INTO statement, executes the query using the MySQL connection pool, logs the transaction, and returns a JSON-formatted response with the result or an error message.

  private async handleInsertData(request: any, transactionId: string) {
    if (!isValidSqlQueryArgs(request.params.arguments)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'SQL 查询参数无效。'
      );
    }
  
    const query = request.params.arguments.query;
  
    if (!isInsertQuery(query)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'insert_data 工具仅允许 INSERT INTO 查询。'
      );
    }
  
    console.error(`[${transactionId}] 执行 INSERT 查询: ${query}`);
  
    try {
      const [result] = await this.pool.query(query);
      console.error(`[${transactionId}] 数据插入成功`);
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify({
              success: true,
              message: '数据插入成功',
              result
            }, null, 2),
          },
        ],
      };
    } catch (error) {
      console.error(`[${transactionId}] 查询出错:`, error);
      if (error instanceof Error) {
        return {
          content: [
            {
              type: 'text',
              text: `MySQL 错误: ${error.message}`,
            },
          ],
          isError: true,
        };
      }
      throw error;
    }
  }

• src/index.ts:133-142 (schema)

  Input schema for the insert_data tool, defining a required 'query' property of type string for the SQL INSERT INTO statement.

  inputSchema: {
    type: 'object',
    properties: {
      query: {
        type: 'string',
        description: '要执行的 SQL INSERT INTO 语句',
      },
    },
    required: ['query'],
  },

• src/index.ts:130-143 (registration)

  Registration of the insert_data tool in the ListTools response, including name, description, and input schema.

  {
    name: 'insert_data',
    description: '向 MySQL 数据库表插入数据',
    inputSchema: {
      type: 'object',
      properties: {
        query: {
          type: 'string',
          description: '要执行的 SQL INSERT INTO 语句',
        },
      },
      required: ['query'],
    },
  },

• src/index.ts:200-201 (registration)

  Dispatch registration in the CallToolRequest handler switch statement, routing 'insert_data' calls to the handleInsertData method.

  case 'insert_data':
    return this.handleInsertData(request, transactionId);

• src/index.ts:40-41 (helper)

  Helper function that checks if a given SQL query starts with 'insert into' (case-insensitive, trimmed), used for validation in the handler.

  const isInsertQuery = (query: string): boolean =>
    query.trim().toLowerCase().startsWith('insert into');