Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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5.5.37
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None
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OSX, CentOS
Description
There is a difference between MariaDB's behavior and MySQL 5.5 when a query is doing select @var := count(*). MySQL would return the number of rows matched while Maria returns 0.. Its unclear to me which behavior is actually correct.
While I personally wouldn't have used the := syntax here, someone else did and it broke our application a little bit..
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Minimal Example:
drop database if exists `test_example`; |
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create database test_example; |
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use test_example; |
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CREATE TABLE `blarg` ( |
`id` int(10) unsigned NOT NULL AUTO_INCREMENT, |
`v` varchar(10), |
PRIMARY KEY (`id`) |
) ENGINE=InnoDB;
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insert into blarg (`v`) values ('AAA'); |
insert into blarg (`v`) values ('AAA'); |
insert into blarg (`v`) values ('AAA'); |
insert into blarg (`v`) values ('BBB'); |
insert into blarg (`v`) values ('BBB'); |
insert into blarg (`v`) values ('CCC'); |
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MariaDB [test_example]> select count(*), @a := count(*), v from blarg group by v; |
+----------+----------------+------+ |
| count(*) | @a := count(*) | v | |
+----------+----------------+------+ |
| 3 | 0 | AAA |
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| 2 | 0 | BBB |
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| 1 | 0 | CCC |
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+----------+----------------+------+ |
3 rows in set (0.00 sec) |
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mysql> select count(*), @a := count(*), v from blarg group by v; |
+----------+----------------+------+ |
| count(*) | @a := count(*) | v | |
+----------+----------------+------+ |
| 3 | 3 | AAA |
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| 2 | 2 | BBB |
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| 1 | 1 | CCC |
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+----------+----------------+------+ |
3 rows in set (0.00 sec) |
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mysql>
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