[SQL Service]从一张表取值更新另一张表字段

1、

update table_A

set  table_A_column = ab.column

from table_A aa

        left join table_B ab on aa.xx = ab.xx

where aa.xx = xx

2、

update table_A

set  table_A_column = table_B.column

from table_A,table_B

where table_A.xx = table_B.xx