MCPQL

Instructions

Implementation Reference

• src/tools/dataOperations.ts:71-90 (handler)

  The core handler function that performs permission validation using validateQueryPermission, executes the provided SQL query against the database pool, and returns the recordset or an error.

  export const mcp_execute_query = async (args: { query: string }): Promise<ToolResult<any[]>> => {
    const { query } = args;
    console.log('Executing mcp_execute_query with query:', query);
  
    // Security validation for SQL query execution
    const permission = validateQueryPermission(query);
    if (!permission.allowed) {
      return { success: false, error: permission.message || 'Query execution not allowed' };
    }
  
    try {
      const pool = getPool();
      const result = await pool.request().query(query);
      return { success: true, data: result.recordset };
    } catch (error: any) {
      // Only log the error message, not the full stack trace for cleaner output
      console.error(`Error in mcp_execute_query: ${error.message}`);
      return { success: false, error: error.message };
    }
  };

• src/tools.ts:102-116 (schema)

  Tool schema definition in the MCP_MSQL_TOOLS array, specifying the name, description, and inputSchema requiring a 'query' string parameter.

  {
    name: "mcp_execute_query",
    description: "Execute a raw SQL query and return the results",
    inputSchema: {
      type: "object",
      properties: {
        query: {
          type: "string",
          description: "The SQL query to execute. IMPORTANT: When referencing objects, use bracketed, schema-qualified names (e.g., SELECT * FROM [dbo].[Users])."
        }
      },
      required: ["query"]
    }
  },

• src/tools/index.ts:30-33 (registration)

  Re-exports the mcp_execute_query handler from dataOperations.js as part of the tools index module.

  export {
    mcp_execute_procedure, // Execute stored procedure
    mcp_execute_query       // Execute SQL query
  } from './dataOperations.js';