describe-table
Retrieve and analyze the structure of specified tables in Microsoft SQL Server, including column details and schema information, to streamline database management and query optimization.
Instructions
查看指定資料表的欄位結構
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| schemaName | No | 結構描述名稱 (預設: dbo) | dbo |
| tableName | Yes | 資料表名稱 |
Implementation Reference
- src/index.ts:279-350 (handler)Executes the 'describe-table' tool: validates connection and database, sanitizes input names, fetches columns via MSSQLManager, formats and returns the table structure as a text list.async ({ tableName, schemaName }) => { 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 工具建立連接。' } ] } } 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 sanitizedTableName = sanitizeTableName(tableName) const sanitizedSchemaName = sanitizeTableName(schemaName) const columns = await mssqlManager.getTableColumns(sanitizedTableName, sanitizedSchemaName) if (columns.length === 0) { return { content: [ { type: 'text' as const, text: `找不到資料表 ${sanitizedSchemaName}.${sanitizedTableName}。` } ] } } const columnList = columns.map(col => { let typeInfo = col.data_type if (col.character_maximum_length) { typeInfo += `(${col.character_maximum_length})` } else if (col.numeric_precision && col.numeric_scale !== null) { typeInfo += `(${col.numeric_precision},${col.numeric_scale})` } const nullable = col.is_nullable === 'YES' ? 'NULL' : 'NOT NULL' return `- ${col.column_name}: ${typeInfo} ${nullable}` }).join('\n') return { content: [ { type: 'text' as const, text: `資料表 ${sanitizedSchemaName}.${sanitizedTableName} 的欄位結構:\n${columnList}` } ] } } catch (error) { return { content: [ { type: 'text' as const, text: `查看資料表結構失敗: ${error instanceof Error ? error.message : String(error)}` } ] } } }
- src/index.ts:271-278 (schema)Zod input schema defining parameters for tableName (required string) and schemaName (optional string, default 'dbo').{ title: '查看表格結構', description: '查看指定資料表的欄位結構', inputSchema: { tableName: z.string().describe('資料表名稱'), schemaName: z.string().optional().default('dbo').describe('結構描述名稱 (預設: dbo)'), } },
- src/index.ts:269-351 (registration)Registers the 'describe-table' tool on the MCP server with title, description, input schema, and handler function.server.registerTool( 'describe-table', { title: '查看表格結構', description: '查看指定資料表的欄位結構', inputSchema: { tableName: z.string().describe('資料表名稱'), schemaName: z.string().optional().default('dbo').describe('結構描述名稱 (預設: dbo)'), } }, async ({ tableName, schemaName }) => { 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 工具建立連接。' } ] } } 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 sanitizedTableName = sanitizeTableName(tableName) const sanitizedSchemaName = sanitizeTableName(schemaName) const columns = await mssqlManager.getTableColumns(sanitizedTableName, sanitizedSchemaName) if (columns.length === 0) { return { content: [ { type: 'text' as const, text: `找不到資料表 ${sanitizedSchemaName}.${sanitizedTableName}。` } ] } } const columnList = columns.map(col => { let typeInfo = col.data_type if (col.character_maximum_length) { typeInfo += `(${col.character_maximum_length})` } else if (col.numeric_precision && col.numeric_scale !== null) { typeInfo += `(${col.numeric_precision},${col.numeric_scale})` } const nullable = col.is_nullable === 'YES' ? 'NULL' : 'NOT NULL' return `- ${col.column_name}: ${typeInfo} ${nullable}` }).join('\n') return { content: [ { type: 'text' as const, text: `資料表 ${sanitizedSchemaName}.${sanitizedTableName} 的欄位結構:\n${columnList}` } ] } } catch (error) { return { content: [ { type: 'text' as const, text: `查看資料表結構失敗: ${error instanceof Error ? error.message : String(error)}` } ] } } } )
- src/database.ts:158-178 (helper)MSSQLManager method that queries INFORMATION_SCHEMA.COLUMNS to retrieve column information for the specified table and schema.async getTableColumns(tableName: string, schemaName: string = 'dbo'): Promise<ColumnInfo[]> { if (!this.currentDatabase) { throw new Error('尚未選擇資料庫') } const query = ` SELECT COLUMN_NAME as column_name, DATA_TYPE as data_type, IS_NULLABLE as is_nullable, CHARACTER_MAXIMUM_LENGTH as character_maximum_length, NUMERIC_PRECISION as numeric_precision, NUMERIC_SCALE as numeric_scale FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = '${tableName}' AND TABLE_SCHEMA = '${schemaName}' ORDER BY ORDINAL_POSITION ` const result = await this.executeQuery(query) return result.recordset as ColumnInfo[] }
- src/types.ts:44-51 (schema)TypeScript interface defining the structure of column information returned by getTableColumns.export interface ColumnInfo { column_name: string data_type: string is_nullable: string character_maximum_length: number | null numeric_precision: number | null numeric_scale: number | null }