MySQL MCP Server

Instructions

Implementation Reference

• src/server.ts:105-116 (schema)

  Defines the input schema, description, and registers the mysql_describe_table tool in the ListTools response.

  {
    name: 'mysql_describe_table',
    description: '查看表结构',
    inputSchema: {
      type: 'object',
      properties: {
        tableName: { type: 'string', description: '表名称' },
        database: { type: 'string', description: '数据库名称（可选）' },
      },
      required: ['tableName'],
    },
  },

• src/server.ts:356-367 (handler)

  MCP server handler for mysql_describe_table tool that calls DatabaseManager.describeTable and returns formatted response.

  private async handleDescribeTable(args: { tableName: string; database?: string }): Promise<any> {
    const columns = await this.dbManager.describeTable(args.tableName, args.database);
    
    return {
      content: [
        {
          type: 'text',
          text: `表 ${args.tableName} 结构:\n${JSON.stringify(columns, null, 2)}`,
        },
      ],
    };
  }

• src/database.ts:149-170 (handler)

  Core implementation in DatabaseManager that executes the SQL query against information_schema.COLUMNS to retrieve table structure.

  async describeTable(tableName: string, database?: string): Promise<ColumnInfo[]> {
    const dbName = database || this.config?.database;
    if (!dbName) {
      throw new Error('请指定数据库名称');
    }
  
    const result = await this.query(`
      SELECT 
        COLUMN_NAME as field,
        COLUMN_TYPE as type,
        IS_NULLABLE as \`null\`,
        COLUMN_KEY as \`key\`,
        COLUMN_DEFAULT as \`default\`,
        EXTRA as extra,
        COLUMN_COMMENT as comment
      FROM information_schema.COLUMNS
      WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?
      ORDER BY ORDINAL_POSITION
    `, [dbName, tableName]);
    
    return result.rows as ColumnInfo[];
  }

• src/types.ts:26-33 (schema)

  Type definition for ColumnInfo used in the describeTable output.

  export interface ColumnInfo {
    field: string;
    type: string;
    null: string;
    key: string;
    default: string | null;
    extra: string;
    comment: string;