是否有SQL语句可以返回表中列的类型?


当前回答

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

其他回答

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。

在TSQL/MSSQL中,它看起来像:

SELECT t.name, c.name 
FROM sys.tables t 
JOIN sys.columns c ON t.object_id = c.object_id
JOIN sys.types y ON y.user_type_id = c.user_type_id
WHERE t.name = ''

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]

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]');