使用MS SQL的另一个变体:

SELECT TYPE_NAME(system_type_id) 
FROM sys.columns 
WHERE name = 'column_name'
AND [object_id] = OBJECT_ID('[dbo].[table_name]');

要检索实际声明的数据类型，例如在动态SQL To ALTER COLUMNs中使用，可以使用这样的方法:

SELECT
    TABLE_NAME, 
    COLUMN_NAME,
    DATA_TYPE
        + CASE WHEN DATA_TYPE IN ('char','nchar','varchar','nvarchar','binary','varbinary')
                    AND CHARACTER_MAXIMUM_LENGTH > 0 THEN
                 COALESCE('('+CONVERT(varchar,CHARACTER_MAXIMUM_LENGTH)+')','')
            ELSE '' END
        + CASE WHEN DATA_TYPE IN ('decimal','numeric') THEN
                COALESCE('('+CONVERT(varchar,NUMERIC_PRECISION)+','+CONVERT(varchar,NUMERIC_SCALE)+')','')
            ELSE '' END
        AS Declaration_Type,
    CASE WHEN IS_NULLABLE='NO' THEN 'NOT ' ELSE '' END + 'NULL' AS Nullable
FROM INFORMATION_SCHEMA.COLUMNS
ORDER BY 1,2

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')

这同样适用于只选择列名及其各自的字符类型

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

使用SQL Server:

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

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`;