I would like using SELECT, inside SELECT to get some values (i allready done this).
Problem is, i would like to display this data in mysql, sum, and that's the problem.I won't post original code, but look at this example.
SELECT id, (SELECT COUNT(x) FROM xyz where id=usr.id) as value_1,
(SELECT COUNT(y) FROM zyx where id=usr.id) as value_2
FROM users AS usr
That's work correct, but i would like to sum value_1 and value_2.
When i do this
SELECT id,
(SELECT COUNT(x) FROM xyz where id=usr.id) as value_1,
(SELECT COUNT(y) FROM zyx where id=usr.id) as value_2,
(value_1+value_2) as my_sum_value
FROM users AS usr
i got information about "value_1" and "value_2" not found.
I figure out, that i can use
SELECT id,
(SELECT COUNT(x) FROM xyz where id=usr.id) as value_1,
(SELECT COUNT(y) FROM zyx where id=usr.id) as value_2,
((SELECT COUNT(x) FROM xyz where id=usr.id) as value_1,
(SEL开发者_运维问答ECT COUNT(y) FROM zyx where id=usr.id)+
(SELECT COUNT(y) FROM zyx where id=usr.id) as value_2) as my_sum_value
FROM users AS usr
But, i have to write "twice" all of my code. Why i can't use "alias" called "value_1" and "value_2" ? After query, this values are correct, how to access sum value?
try this
SELECT id,
SUM(
(SELECT COUNT(x) FROM xyz where id=usr.id),
(SELECT COUNT(y) FROM zyx where id=usr.id)
) as my_sum_value
FROM users AS usr
you can't use the variables because they're in a subquery...
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