declare @default sysname, @sql nvarchar(max)

BEGIN

??? IF? EXISTS(SELECT 1 FROM SYSCOLUMNS A,SYSOBJECTS B

????? WHERE A.id=B.id AND B.name='TableName' AND B.xtype='u' AND A.name='ColumnName')

??????????? BEGIN

????????????????? SELECT @default = name

????????????????? from sys.default_constraints

????????????????? WHERE parent_object_id = object_id(' TableName ')

????????????????? AND type = 'D'

????????????????? AND parent_column_id = (

??????????????????????? select column_id

??????????????????????? from sys.columns

??????????????????????? where object_id = object_id(' TableName ')

??????????????????????? and name = 'Accounts'

??????????????????????? )

?

????????????????? set @sql = N'alter table [ TableName ] ? drop constraint ' + @default

????????????????? exec sp_executesql @sql

?

????????????????? alter table [ TableName ] drop column [ ColumnName ]

??????????? END

END

刪除SQL表中的字段