是否有SQL语句可以返回表中列的类型?


当前回答

MS SQL的另一个选项是用你想要的类型的查询替换这里的选择查询:

declare @sql varchar(4000);

set @sql = 'select ''hi'' as greeting';

select * from master.sys.dm_exec_describe_first_result_set (@sql, Null, 0);

其他回答

在我的情况下,我需要获得动态SQL的数据类型(Shudder!)无论如何,这里是一个函数,我创建返回完整的数据类型。例如,它不会返回'decimal',而是返回decimal (18,4): dbo。GetLiteralDataType

MS SQL的另一个选项是用你想要的类型的查询替换这里的选择查询:

declare @sql varchar(4000);

set @sql = 'select ''hi'' as greeting';

select * from master.sys.dm_exec_describe_first_result_set (@sql, Null, 0);

对于Apache Derby,如下面的答案所示:

select columndatatype from sys.syscolumns
  where referenceid = (
    select tableid from sys.systables
    where tablename = 'YOUR_TABEL_NAME'
    and columnname= 'YOUR_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"))