Question

如何在Query Builder中进行MySQL查询？

SELECT traction_instances.*, 
           (SELECT COUNT(station_id) 
              FROM traction_stations 
             WHERE traction_instances.instance_id = traction_stations.monitoring_instance) as `count stations`
FROM traction_instances

我迄今为止所做的尝试如下：

$instances = DB::connection('monitors')->table(DB::raw('traction_instances as ti, traction_stations as ts'))
            ->select(array('ti.instance_id', 'ti.status', 'ti.cpu_usage', DB::raw('count(ts.station_id) as station_count')))
            ->where(DB::raw('ti.instance_id'), '=', DB::raw('ts.monitoring_instance'))
            ->get();

有了这个，我得到了单一的实例＆＃39;行（并且其中有4个）具有＆＃39;站点＆＃39;实例正在监视，但我需要所有实例，如果没有该实例正在监视的站，则station_count应为0。

Answer 1

找到解决方案：

$instances = DB::connection('monitors')->table('traction_instances as ti')
            ->where('ti.instance_type', 'Audio Stream Processor')
            ->select(DB::raw('ti.*, (SELECT COUNT(*) FROM traction_stations AS ts WHERE ti.instance_id = ts.monitoring_instance) AS station_count'))
            ->get();

使用Query Builder的Laravel 4.2子查询

1 个答案: