如何以有效的方式合并来自多个表的结果 Laravel答案

【问题标题】：How to merge result from multiple tables in efficient way Laravel如何以有效的方式合并来自多个表的结果 Laravel
【发布时间】：2020-02-15 14:55:45
【问题描述】：

我必须合并 Laravel 中多个表的结果。目前我正在使用以下方式：

public function getMachines(Request $request) {
        $vendor_id = Auth::id();
        $ml_8_machine=ML8Machine::where('vendor_id','=',$vendor_id)->get();
        $ml_16_machine=ML16Machine::where('vendor_id','=',$vendor_id)->get();
        $ml_32_machine=ML32Machine::where('vendor_id','=',$vendor_id)->get();
        $ml_64_machine=ML64Machine::where('vendor_id','=',$vendor_id)->get();
        $ml_96_machine=ML96Machine::where('vendor_id','=',$vendor_id)->get();
        $ml_128_machine=ML128Machine::where('vendor_id','=',$vendor_id)->get();
        $machines = collect($ml_8_machine)
                        ->merge($ml_16_machine)
                        ->merge($ml_32_machine)
                        ->merge($ml_64_machine)
                        ->merge($ml_96_machine)
                        ->merge($ml_128_machine);
        return view('vendor.machines', compact('machines'));      
    }

我正在寻找一种有效的方法来执行查询并将结果合并到一个集合中。

【问题讨论】：

这些机器学习表有相同的列吗？

标签： mysql sql laravel laravel-5 eloquent

【解决方案1】：

如果您的列相同，您可以使用unionAll 来合并记录。这将降低 IO 成本：

public function getMachines(Request $request) {
        $vendor_id = Auth::id();
        $ml_8_machine=ML8Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $ml_16_machine=ML16Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $ml_32_machine=ML32Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $ml_64_machine=ML64Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $ml_96_machine=ML96Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $ml_128_machine=ML128Machine::where('vendor_id','=',$vendor_id)->select('column1', 'column2'...);
        $machines = $ml_8_machine->unionAll($ml_16_machine)
                        ->unionAll($ml_32_machine)
                        ->unionAll($ml_64_machine)
                        ->unionAll($ml_96_machine)
                        ->unionAll($ml_128_machine)
                        ->get();
        return view('vendor.machines', compact('machines'));      
    }

请记住，您需要保持每列与其他列的顺序相同。

您也可以在此查询中添加paginate()：

$machines = $ml_8_machine->unionAll($ml_16_machine)
                        ->unionAll($ml_32_machine)
                        ->unionAll($ml_64_machine)
                        ->unionAll($ml_96_machine)
                        ->unionAll($ml_128_machine)
                        ->paginate(10);

【讨论】：

【解决方案2】：

也许其中一种方法可以帮助你

$vendor_id = Auth::id();

$ml_8_machine=ML8Machine::where('vendor_id','=',$vendor_id)->get();
$ml_16_machine=ML16Machine::where('vendor_id','=',$vendor_id)->get();
$ml_32_machine=ML32Machine::where('vendor_id','=',$vendor_id)->get();
$ml_64_machine=ML64Machine::where('vendor_id','=',$vendor_id)->get();
$ml_96_machine=ML96Machine::where('vendor_id','=',$vendor_id)->get();
$machines = ML128Machine::where('vendor_id','=',$vendor_id)
        ->union($ml_8_machine)
        ->union($ml_16_machine)
        ->union($ml_32_machine)
        ->union($ml_64_machine)
        ->union($ml_96_machine)
        ->get();

return view('vendor.machines', compact('machines'));

或使用原始查询methods

(SELECT * from ml_8_machine where `vendor_id` = '?')
UNION
(SELECT * from ml_16_machine where `vendor_id` = '?')

或

SELECT * from ml_8_machine, ml_16_machine where `ml_8_machine.vendor_id` = '?' AND `ml_16_machine.vendor_id` = '?'

【讨论】：

【解决方案3】：

你可以使用collapse()方法

$collection = collect([$ml_8_machine, $ml_16_machine, $ml_32_machine, $ml_64_machine, $ml_96_machine, $ml_128_machine]);

$machines = $collection->collapse();

//dump($machines);

return view('vendor.machines', compact('machines'));

【讨论】：