Can't sum be used in two tables?

白日梦游

The total data is incorrect
SELECT SUM (a.a) AS AA, SUM (b.b) AS BB
FROM a, b

unkmass

SELECT SUM (a.a) AS AA, SUM (b.b) AS BB
FROM a, b
===============
You are the calculated Cartesian product, of course, it is wrong, you should add the associated conditions, namely:
SELECT SUM (a.a) AS AA, SUM (b.b) AS BB
FROM a, b
where a. primary key = b. primary key

johnseven

yes

我是杀人狂

ls positive solution ..

wgfxman

If you really want Cartesian multiplication, where 1 = 1 is fine

fanfan1980

--try

select
AA = (select sum (a) from a),
BB = (select sum (b) from b)