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')

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);

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SQL Server，这个系统存储过程将返回所有表信息，包括列数据类型:

exec sp_help YOURTABLENAME

在oracle SQL中，你可以这样做:

SELECT
    DATA_TYPE
FROM
    all_tab_columns 
WHERE
    table_name = 'TABLE NAME' -- in uppercase
AND column_name = 'COLUMN NAME' -- in uppercase

使用TSQL /该软件

该查询将为您提供:表名、列名、数据类型、数据类型长度和允许的空值

SELECT TABLE_NAME,COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'your_table_name'

唯一需要更改的是your_table_name。