多表关联删除,删除某张报表满足指定条件的记录:
写法1:
delete from ZWKMJE
from ZWKMZD
where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%' 写法2:
delete from ZWKMJE
where exists
(select 1 from ZWKMZD
where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%') 写法3:
delete from ZWKMJE
where ZWKMJE_KMBH in
(select ZWKMZD_KMBH from ZWKMZD
where ZWKMZD_KMMC like '%现金%')
这三种方法的效率是怎么样的?能解释下为什么吗?
写法1:
delete from ZWKMJE
from ZWKMZD
where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%' 写法2:
delete from ZWKMJE
where exists
(select 1 from ZWKMZD
where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%') 写法3:
delete from ZWKMJE
where ZWKMJE_KMBH in
(select ZWKMZD_KMBH from ZWKMZD
where ZWKMZD_KMMC like '%现金%')
这三种方法的效率是怎么样的?能解释下为什么吗?
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where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%'
支持不??
where ZWKMZD.ZWKMZD_KMBH =ZWKMJE.ZWKMJE_KMBH
and ZWKMZD.ZWKMZD_KMMC like '%现金%'
支持不??