只是两个使用例子，从别处摘来的，留着后面参考：

方式一：

1 $connection  = Yii::$app->db;2 $sql     = "select * from hd_article where aid<".$aid." order by aid desc limit 1";3 $command = $connection->createCommand($sql);4 $res     = $command->queryAll($sql);

 

方式二：

1  $query = new \yii\db\Query();2  $query->select('pa_call.id,pa_call.tableid,pa_call.time as msgtime,pa_table_area.id as areaid,pa_table_area.areaname as area,pa_table.tablename,pa_call.message as msg,pa_call.new as needoper,pa_call.status as isdone,pa_employee.username as oper')3             ->from(Call::tableName())4             ->join('LEFT JOIN',Table::tableName(),'pa_call.tableid=pa_table.id')5             ->join('LEFT JOIN',Area::tableName(),'pa_table_area.id=pa_table.areaid')6             ->join('LEFT JOIN',Employee::tableName(),'pa_call.employeeid=pa_employee.id')7             ->where($where);8         $command = $query->createCommand();9         $data = $command->queryAll();