我們在做sql更新時，為防止sql重復執行報錯，需要對所需要執行的對象進行判斷是否存在；

常用判斷腳本如下：

判斷視圖是否存在

IF object_id(‘viewname‘) IS not NULL
begin
 --操作
 --drop view viewname
end

IF object_id(‘tablename‘) IS NULL
BEGIN
 --操作
END

IF NOT EXISTS (SELECT 1 FROM dbo.syscolumns WHERE [name]=‘columnname
 
‘ AND id=object_id(‘tablename‘))
begin

 --操作

end

IF exists (select 1 from sysobjects where xtype=‘fn‘ and name=‘funcname‘)
BEGIN
 --drop function funcname
end

IF exists (select 1 from sysobjects where xtype=‘p‘ and name=‘procname‘)
BEGIN
 --drop proc procname
 

end

IF exists (select * from sysobjects where id=object_id(N‘tr_es_Order_upd‘) and objectproperty(id,N‘IsTrigger‘)=1) 
begin
--DROP TRIGGER  tr_es_Order_upd ;
end

IF NOT EXISTS (select 1 from sys.indexes where name=‘index_cb_WarehouseInOutDtl_MaterialsGUID
 
‘)
begin
--操作
END

SQL 常用判斷語句