MSSQL MCP Server

Instructions

Implementation Reference

• src/index.ts:205-265 (handler)

  The handler function for the 'list-tables' MCP tool. It checks if connected to a database, verifies a current database is selected, calls mssqlManager.getTables() to fetch the list of tables, formats them as a bulleted list with schema, name, and type, and returns the result in MCP content format. Handles errors appropriately.

  async () => {
    try {
      if (!mssqlManager.isConnected()) {
        return {
          content: [
            {
              type: 'text' as const,
              text: '錯誤: 尚未連接到資料庫伺服器。請先使用 connect-database 工具建立 সংযোগ。'
            }
          ]
        }
      }
  
      const currentDb = mssqlManager.getCurrentDatabase()
      if (!currentDb) {
        return {
          content: [
            {
              type: 'text' as const,
              text: '錯誤: 尚未選擇資料庫。請先使用 switch-database 工具選擇資料庫。'
            }
          ]
        }
      }
  
      const tables = await mssqlManager.getTables()
  
      if (tables.length === 0) {
        return {
          content: [
            {
              type: 'text' as const,
              text: `資料庫 ${currentDb} 中沒有找到資料表。`
            }
          ]
        }
      }
  
      const tableList = tables.map(table =>
        `- ${table.table_schema}.${table.table_name} (${table.table_type})`
      ).join('\n')
  
      return {
        content: [
          {
            type: 'text' as const,
            text: `資料庫 ${currentDb} 中找到 ${tables.length} 個資料表:\n${tableList}`
          }
        ]
      }
    } catch (error) {
      return {
        content: [
          {
            type: 'text' as const,
            text: `列出資料表失敗: ${error instanceof Error ? error.message : String(error)}`
          }
        ]
      }
    }
  }

• src/types.ts:37-41 (schema)

  TableInfo interface defining the structure of table metadata returned by getTables(), used in the tool's output processing.

  export interface TableInfo {
    table_name: string
    table_schema: string
    table_type: string
  }

• src/index.ts:199-266 (registration)

  Registration of the 'list-tables' tool with the MCP server, including title, description (no input schema), and reference to the inline handler function.

  server.registerTool(
    'list-tables',
    {
      title: '列出資料表',
      description: '列出目前資料庫中的所有資料表'
    },
    async () => {
      try {
        if (!mssqlManager.isConnected()) {
          return {
            content: [
              {
                type: 'text' as const,
                text: '錯誤: 尚未連接到資料庫伺服器。請先使用 connect-database 工具建立 সংযোগ。'
              }
            ]
          }
        }
  
        const currentDb = mssqlManager.getCurrentDatabase()
        if (!currentDb) {
          return {
            content: [
              {
                type: 'text' as const,
                text: '錯誤: 尚未選擇資料庫。請先使用 switch-database 工具選擇資料庫。'
              }
            ]
          }
        }
  
        const tables = await mssqlManager.getTables()
  
        if (tables.length === 0) {
          return {
            content: [
              {
                type: 'text' as const,
                text: `資料庫 ${currentDb} 中沒有找到資料表。`
              }
            ]
          }
        }
  
        const tableList = tables.map(table =>
          `- ${table.table_schema}.${table.table_name} (${table.table_type})`
        ).join('\n')
  
        return {
          content: [
            {
              type: 'text' as const,
              text: `資料庫 ${currentDb} 中找到 ${tables.length} 個資料表:\n${tableList}`
            }
          ]
        }
      } catch (error) {
        return {
          content: [
            {
              type: 'text' as const,
              text: `列出資料表失敗: ${error instanceof Error ? error.message : String(error)}`
            }
          ]
        }
      }
    }
  )

• src/database.ts:137-153 (helper)

  Core helper method MSSQLManager.getTables() that executes a SQL query against INFORMATION_SCHEMA.TABLES to retrieve all tables (name, schema, type) in the current database, returning typed TableInfo[] array.

  async getTables(): Promise<TableInfo[]> {
    if (!this.currentDatabase) {
      throw new Error('尚未選擇資料庫')
    }
  
    const query = `
      SELECT 
        TABLE_NAME as table_name,
        TABLE_SCHEMA as table_schema,
        TABLE_TYPE as table_type
      FROM INFORMATION_SCHEMA.TABLES
      ORDER BY TABLE_SCHEMA, TABLE_NAME
    `
    
    const result = await this.executeQuery(query)
    return result.recordset as TableInfo[]
  }