Laravel使用addSelect时报stripos()参数1需为字符串却传入对象错误怎么解决

• 核心错误是查询构造器的链式调用结构断裂：你将$mahasiswa=DB::table('MSMHS')->单独拆分到了代码块外部，尾部的->没有后续衔接的调用方法，导致Laravel解析查询参数时，将后续生成的查询对象错误传入要求字符串类型的stripos方法，触发类型报错。

将链式调用结构合并为完整连贯的代码即可，修复后完整代码如下：

$mahasiswa = DB::table('MSMHS')
    ->select('nimhsMSMHS','noktpMSMHS','nmmhsMSMHS','tahunMSMHS','kdfakMSMHS','kdjurMSMHS','kdjekMSMHS','tplhrMSMHS','tglhrMSMHS','telhpMSMHS','staklMSMHS','emailMSMHS')
    ->addSelect(['sksMSMHS' => function($query) {
        $query->select('SKSTTHSIPK')
            ->from('HSIPK')
            ->whereColumn('NIMHSHSIPK', 'nimhsMSMHS')
            ->orderBy('THSMSHSIPK', 'DESC')
            ->limit(1);
    }])
    ->where('MSMHS.staklMSMHS', 'A')
    ->where('MSMHS.nimhsMSMHS', '152017015')
    ->get();

如果使用的Laravel版本低于5.6，闭包形式的addSelect可能存在解析兼容问题，可替换为原生查询写法：

$mahasiswa = DB::table('MSMHS')
    ->select('nimhsMSMHS','noktpMSMHS','nmmhsMSMHS','tahunMSMHS','kdfakMSMHS','kdjurMSMHS','kdjekMSMHS','tplhrMSMHS','tglhrMSMHS','telhpMSMHS','staklMSMHS','emailMSMHS')
    ->selectRaw('(SELECT SKSTTHSIPK FROM HSIPK WHERE NIMHSHSIPK = MSMHS.nimhsMSMHS ORDER BY THSMSHSIPK DESC LIMIT 1) as sksMSMHS')
    ->where('MSMHS.staklMSMHS', 'A')
    ->where('MSMHS.nimhsMSMHS', '152017015')
    ->get();

内容的提问来源于stack exchange，提问作者Bachtiar