MSSQL MCP Server

Instructions

Implementation Reference

• src/tools/CreateTableTool.ts:28-48 (handler)

  The `run` method executes the tool: validates input, builds CREATE TABLE query from tableName and columns, executes it via mssql, returns success/error.

  async run(params: any) {
    try {
      const { tableName, columns } = params;
      if (!Array.isArray(columns) || columns.length === 0) {
        throw new Error("'columns' must be a non-empty array");
      }
      const columnDefs = columns.map((col: any) => `[${col.name}] ${col.type}`).join(", ");
      const query = `CREATE TABLE [${tableName}] (${columnDefs})`;
      await new sql.Request().query(query);
      return {
        success: true,
        message: `Table '${tableName}' created successfully.`
      };
    } catch (error) {
      console.error("Error creating table:", error);
      return {
        success: false,
        message: `Failed to create table: ${error}`
      };
    }
  }

• src/tools/CreateTableTool.ts:8-26 (schema)

  Input schema defining required parameters: `tableName` (string) and `columns` (array of {name, type} objects).

  inputSchema = {
    type: "object",
    properties: {
      tableName: { type: "string", description: "Name of the table to create" },
      columns: {
        type: "array",
        description: "Array of column definitions (e.g., [{ name: 'id', type: 'INT PRIMARY KEY' }, ...])",
        items: {
          type: "object",
          properties: {
            name: { type: "string", description: "Column name" },
            type: { type: "string", description: "SQL type and constraints (e.g., 'INT PRIMARY KEY', 'NVARCHAR(255) NOT NULL')" }
          },
          required: ["name", "type"]
        }
      }
    },
    required: ["tableName", "columns"],
  } as any;

• src/index.ts:115-119 (registration)

  In ListToolsRequestHandler, `createTableTool` is added to the list of available tools (in non-readonly mode).

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools: isReadOnly
      ? [listTableTool, readDataTool, describeTableTool] // todo: add searchDataTool to the list of tools available in readonly mode once implemented
      : [insertDataTool, readDataTool, describeTableTool, updateDataTool, createTableTool, createIndexTool, dropTableTool, listTableTool], // add all new tools here
  }));

• src/index.ts:135-137 (registration)

  In CallToolRequestHandler switch statement, dispatches to `createTableTool.run(args)` when name matches.

  case createTableTool.name:
    result = await createTableTool.run(args);
    break;

• src/index.ts:92-92 (registration)

  Instantiation of the CreateTableTool instance used throughout the server.

  const createTableTool = new CreateTableTool();