是否有SQL语句可以返回表中列的类型?


当前回答

使用此查询获取Schema, Table, Column,Type, max_length, is_nullable

SELECT QUOTENAME(SCHEMA_NAME(tb.[schema_id])) AS 'Schema'
    ,QUOTENAME(OBJECT_NAME(tb.[OBJECT_ID])) AS 'Table'
    ,C.NAME as 'Column'
    ,T.name AS 'Type'
    ,C.max_length
    ,C.is_nullable
FROM SYS.COLUMNS C INNER JOIN SYS.TABLES tb ON tb.[object_id] = C.[object_id]
    INNER JOIN SYS.TYPES T ON C.system_type_id = T.user_type_id
WHERE tb.[is_ms_shipped] = 0
ORDER BY tb.[Name]

其他回答

对于Spark SQL:

DESCRIBE [db_name.]table_name column_name

使用SQL Server:

SELECT DATA_TYPE 
FROM INFORMATION_SCHEMA.COLUMNS
WHERE 
     TABLE_SCHEMA = 'yourSchemaName' AND
     TABLE_NAME   = 'yourTableName' AND 
     COLUMN_NAME  = 'yourColumnName'

在TSQL中最简单的方法是:

SELECT COLUMN_NAME, DATA_TYPE 
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE TABLE_NAME = 'yourTableName'

如果你正在使用MySQL,你可以试试

SHOW COLUMNS FROM `tbl_name`;

在dev.mysql.com上显示列

否则你应该能做到

DESCRIBE `tbl_name`;

在vb60中,你可以这样做:

Public Cn As ADODB.Connection
'open connection
Dim Rs As ADODB.Recordset
 Set Rs = Cn.OpenSchema(adSchemaColumns, Array(Empty, Empty, UCase("Table"), UCase("field")))

'和sample (valRs是rs.fields("CHARACTER_MAXIMUM_LENGTH").value的函数):

 RT_Charactar_Maximum_Length = (ValRS(Rs, "CHARACTER_MAXIMUM_LENGTH"))
        rt_Tipo = (ValRS(Rs, "DATA_TYPE"))