我不太擅长sql,并且已经尝试了一些方法。考虑到代码的性能,将这5条更新语句组合为一条语句的最佳方法是什么?将会有很大的帮助。非常感谢!
码:
----------------1
Update main_table
set a = (case
..some code.. end)
where condition_2;
----------------2
Update main_table
set b = (case
..some code.. end)
where condition_2
----------------3
Update main_table
set c = (select x from sec_table where conditon_1)
where condition_2
----------------4
Update main_table
set d = (select y from sec_table where conditon_1)
where condition_2
----------------5
Update main_table
set e = (select z from sec_table where conditon_1)
where condition_2
最佳答案
我想你可以这样写:
update main_table
set a = (case ..some code.. end),
b = (case ..some code.. end),
(c, d, e) = (select x, y, z from sec_table where conditon_1)
where condition_2