tab1(
fld int,
fld1 int
)
tab2
(
fld int ,
fld1 int
)我要将tab2中where tab1.fld = tab2.fld的都fld1字段值赋给tab1 fld1字段
用Update set 应怎么写啊
fld int,
fld1 int
)
tab2
(
fld int ,
fld1 int
)我要将tab2中where tab1.fld = tab2.fld的都fld1字段值赋给tab1 fld1字段
用Update set 应怎么写啊
fld1=tb2.fld1
from tb2
where tab1.fld = tab2.fld
到底是修改tb2还是tb1啊
from tb1,tb2
where tab1.fld = tab2.fld
update tab1 set
fld1=tb2.fld1
from tab2
where tab1.fld = tab2.fld
update tab1 set
fld1=tab2.fld1
from tab2
where tab1.fld = tab2.fld
update 单因子污染评价
set 背景值=无机背景值.背景值 from 单因子污染评价, 无机背景值
where 单因子评价.背景值 = 无机背景值.背景值
update tab1
set tab1.fld1=tab2.fld1
from tab2
where tab1.fld=tab2,fld
set a.背景值1=b.背景值1 --确认一下这里要什么
from 单因子污染评价 a, 无机背景值 b
where a.背景值 = b.背景值
set 单因子污染评价.背景值 = 无机背景值.背景值
where 单因子污染评价.指标= 无机背景值.指标
我要设置单因子污染评价与无机背景值中指标相同的记录中的背景值为无机背景值中的背景值
fld1=tb2.fld1
from tb2
where tab1.fld = tab2.fld