update批量更新某一列成其它列对应的值
postgresql
标准sql语句
update AA set name = BB.name , AA.sex = BB.sex from BB where AA.id = BB.id ;
注意不要写成 from AA,BB ，即不要把自身的表写在from后，不然会报异常 ：table name specified more than once
update AA set name = BB.name from AA,BB where AA.id = BB.id
也不要在set 后的列名上加 别名 , 即不要有AA.name , 不然会报异常: column "name" of relation "AA" does not exist
update AA set AA.name = BB.name , AA.sex = BB.sex from BB where AA.id = BB.id ;
oracle
标准sql语句,可以同时更新多个列
UPDATE BB set (name,sex) = (select CC.name, CC.sex from CC where CC.id = BB.id) where BB.id = 1
SQL Server
update A SET A.COL1=B.COL1 FROM A,B where A.KEY=B.KEY where 其它条件限制