Laravel 3中的用户定义的MySQL变量? [英] User-defined MySQL variables in Laravel 3?

问题描述

我想使用用户定义的变量用顺序号更新一组MySQL记录的等级".以下查询可通过MySQL命令行正常运行:

I want to update the "rank" for a group of MySQL records with sequential numbers using a user-defined variable. The following query runs fine via the MySQL command line:

SET @rank:=0; UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=4 ORDER BY score DESC

但是，如果我尝试使用Laravel将其作为Fluent查询运行，则会失败.

But if I try and run it as a Fluent query using Laravel, it fails.

DB::query("SET @rank:=0; UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=4 ORDER BY score DESC");

错误消息:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL 
syntax; check the manual that corresponds to your MySQL server version for the right 
syntax to use near 'UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=4 ORDER BY' at line 1

SQL: SET @rank:=0; UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=4 ORDER BY score DESC

Bindings: array (
)

[已解决]

DB :: raw()来解救！以下作品:

DB::raw() to the rescue! The following works:

DB::query(DB::raw("SET @rank:=0"));
DB::query("UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=4 ORDER BY score DESC");

推荐答案

不可能在一个查询中执行多个语句. Laravel在引擎盖下使用了PDO，可以防止这种情况的发生.您可以尝试通过2个查询调用此方法，因为@rank在连接期间应该可用.

It is not possible to execute multiple statements in one query. Laravel uses PDO under the hood which prevents this. You could attempt to call this over 2 queries instead, since @rank should be available for the duration of the connection.

DB::query("SET @rank:=0");
DB::query("UPDATE scores SET rank=@rank:=@rank+1 WHERE game_id=? ORDER BY score DESC", array(4));

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