如何从现有表中删除列?

我有一个Fname和Lname的table MEN

我需要删除Lname

怎么做呢?


当前回答

ALTER TABLE MEN DROP COLUMN Lname

其他回答

泛型:

ALTER TABLE table_name DROP COLUMN column_name;

在你的情况下:

ALTER TABLE MEN DROP COLUMN Lname;
ALTER TABLE MEN DROP COLUMN Lname

语法:

ALTER TABLE TABLE_NAME DROP COLUMN COLUMN_NAME;

例如:

alter table Employee drop column address;

问题是,你只能从一个不存在的表中删除一个列吗?

BEGIN TRANSACTION

IF exists (SELECT * FROM  sys.columns c 
INNER JOIN  sys.objects t ON (c.[object_id] = t.[object_id])
WHERE t.[object_id] = OBJECT_ID(N'[dbo].[MyTable]')
AND c.[name] = 'ColumnName')
    BEGIN TRY
        ALTER TABLE [dbo].[MyTable] DROP COLUMN ColumnName
    END TRY
    BEGIN CATCH
        print 'FAILED!'
    END CATCH
ELSE
    BEGIN 
        SELECT ERROR_NUMBER() AS ErrorNumber;
        print 'NO TABLE OR COLUMN FOUND !'
    END 

COMMIT  

在现有表中添加列:

ALTER TABLE table_name
 ADD
 column_name DATATYPE NULL  

删除现有表中的列。

ALTER TABLE table_name
DROP COLUMN column_name