mysql_query
Execute SQL queries on MySQL databases to retrieve, update, or manage data through the MCP MySQL Server.
Instructions
Execute a SQL query on the connected MySQL database
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | SQL query to execute | |
| parameters | No | Parameters for prepared statement (optional) |
Implementation Reference
- src/index.ts:306-344 (handler)The primary handler function for the 'mysql_query' tool. It validates input, executes the SQL query using the MySQL pool with optional parameters, handles SELECT (returns rows) and other queries (returns affected rows/insert ID), and returns formatted results or errors.
private async handleQuery(args: any) { if (!this.pool) { throw new Error("Not connected to MySQL. Use mysql_connect first."); } const { query, parameters = [] } = args; if (!query || typeof query !== "string") { throw new Error("Query is required and must be a string"); } try { const [results, fields] = await this.pool.execute(query, parameters); // Handle different types of results if (Array.isArray(results)) { return { content: [ { type: "text", text: `Query executed successfully. ${results.length} rows affected.\n\nResults:\n${JSON.stringify(results, null, 2)}`, }, ], }; } else { const resultInfo = results as mysql.ResultSetHeader; return { content: [ { type: "text", text: `Query executed successfully.\nAffected rows: ${resultInfo.affectedRows}\nInserted ID: ${resultInfo.insertId || "N/A"}`, }, ], }; } } catch (error) { throw new Error(`Query execution failed: ${error instanceof Error ? error.message : String(error)}`); } } - src/index.ts:139-155 (schema)Defines the JSON Schema for input validation of the mysql_query tool, specifying the required 'query' string and optional 'parameters' array of strings.
inputSchema: { type: "object", properties: { query: { type: "string", description: "SQL query to execute", }, parameters: { type: "array", description: "Parameters for prepared statement (optional)", items: { type: "string", }, }, }, required: ["query"], }, - src/index.ts:136-156 (registration)Registration of the mysql_query tool in the ListTools handler response, including name, description, and input schema.
{ name: "mysql_query", description: "Execute a SQL query on the connected MySQL database", inputSchema: { type: "object", properties: { query: { type: "string", description: "SQL query to execute", }, parameters: { type: "array", description: "Parameters for prepared statement (optional)", items: { type: "string", }, }, }, required: ["query"], }, }, - src/index.ts:251-252 (registration)Switch case in the CallToolRequest handler that routes mysql_query invocations to the handleQuery method.
case "mysql_query": return await this.handleQuery(args);