MySQL returns NULL when it places SUM with no records

Question

MySQL returns NULL when it places SUM with no records

Navigation

#1 by (3 votes)

0

I have the code SQL

SELECT sum (r.quantidade_domingo) AS quantity_domingo FROM reports AS r INNER JOIN nodes AS n ON r.id_nucleo = n.id INNER JOIN users AS u ON n.id_user = u.id WHERE u.id_regiao = '1' AND MONTH (r.dia_domingo) = '11'

The problem is that in the reports table there is no record and in the phpmyadmin when I run the command, it returns me quantity_domain as NULL . When I hit Sum (amount_domain_domain) AS_quantity and replaced with r. * it returns me "No Registry" that would be right because in PHP it returns as if it had a line and I do not want it.

php mysql

asked by anonymous 30.11.2015 / 22:30

1 answer

Uncaught Error SyntaxError: Unexpected token = [closed] How to pass another parameter and value with another variable via post?

score 3 · Accepted Answer

This is the default behavior of the SUM function, if it does not have records it returns NULL or if it has no value as well.

You can use COALESCE + SUM to solve this problem:

SELECT COALESCE(SUM(QUANTIDADE), 0) FROM RELATORIO;

Example: SQL Fiddle