不想用循环，这样的UPDate如何实现？

[my_yinger]

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两个表，表A有字段 bm,je,....，表B有字段 bm,je,dyear,.....，需要用B.bm = A.bm ，并且用B.dyear = 2009 的条件，从B表中找出相应的B.je的数据来替换A.je，A.bm和B.bm是交集的关系，A中有的bm记录B中不一定有，反之亦然。如果做循环，到是很容易实现，但如果A、B表的记录很多的话，循环用的时间就会太长了，如何不用循环来实现？

[my_yinger]

[Quote=引用 3 楼 llxlett 的回复:]
SQL codeupdate Aset A.je=B.jefrom A,Bwhere B.bm=A.bmand B.dyear=2009
[/Quote]

我试了，这个就可以，这个写的相对简单，其他的也应该行吧，不过就没在试。谢谢大家。

[liangCK]

UPDATE A SET
    je = B.je
FROM tb1 AS A
    JOIN tb2 AS B
ON A.bm = B.bm AND B.dyear = 2009

[张家可]

update A set A.je=B.je
where B.bm=A.bm and B.dyear=2009

[张家可]

update A set A.je=B.je
from A,B
where B.bm=A.bm and B.dyear=2009

[lihan6415151528]

UPDATE A SET
    je = B.je
FROM tb1 AS A
    JOIN tb2 AS B
ON A.bm = B.bm AND B.dyear = 2009

[guguda2008]

正解

[dawugui]

update a
set je = b.je
from a , b
where a.bm = b.bm and b.dyear = 2009

[13abyKnight]

UPDATE A SET
je = b.je
FROM tb1 AS a
JOIN B AS b
ON a.bm = b.bm AND b.dyear = 2009

[soft_wsx]

没得写了！

[北极之熊熊]

的确没得写了呵呵