在 laravel 中使用多个条件查询数据库的有效方法

Question

是否可以将其设为单个查询？

$yl_min = DB::connection($this->db2)->table('historical')
    ->where([['slug','=',$crypto_id],['low_usd','!=', null]])
    ->whereBetween('created_time',[$this->range_1y,$this->hislatest])
    ->min('low_usd');

$yl = DB::connection($this->db2)->table('historical')
    ->select('id','coin','low_usd','created_time','created_at')
    ->where([['slug','=',$crypto_id],['low_usd',$yl_min]])
    ->whereBetween('created_time',[$this->range_1y,$this->hislatest])
    ->first();

我试过了，但没有成功：

$yl = DB::connection($this->db2)->table('historical')
    ->select('id','coin','created_time','created_at',DB::raw('SELECT MIN(low_usd) as low_usd'))
    ->where([['slug','=',$crypto_id],['low_usd','!=', null]])
    ->whereBetween('created_time',[$this->range_1y,$this->hislatest])
    ->first();

Answer 1

看了你的查询代码，我发现这两个查询条件是一样的，你只想得到min low_usd条记录，

我想你可以只使用多重条件和ORDER BY low_usd ASC，然后取第一个：

$yl = DB::connection($this->db2)->table('historical')
                ->where([['slug','=',$crypto_id],['low_usd','!=', null]])
                ->whereBetween('created_time',[$this->range_1y,$this->hislatest])
                ->orderBy('low_usd','asc')
                ->select('id','coin','low_usd','created_time','created_at')
                ->first();

在此之后，如果你想让这个查询更有效率，

您需要 在 slug、low_usd、created_time

上添加索引

在 laravel 中使用多个条件查询数据库的有效方法

Efficient way to query database with multiple conditions in laravel

multiple-conditions

query-builder

laravel