php Laravel 如何使用查询生成器返回单列值

Laravel how to return single column value using Query Builder

提问by user3349495

I want to use the data from the SQL Query, to explain it further here is my code:

我想使用来自 SQL 查询的数据，进一步解释它，这是我的代码：

    $myquery = DB::table('attendances')->select('user_id')->where('date_only', '=', $newdate)->orderBy('logon','asc')->get();

    $myquery->user_id;

Now I want the value of my $myquery to be USER_ID's value, I get error if I used the Above code -$myquery->user_id;

现在我希望 $myquery 的值是 USER_ID 的值，如果我使用上面的代码 -$myquery->user_id;

回答by Jarek Tkaczyk

EDIT: As of version 5.1pluckis deprecated, since 5.2its meaning is completely different (as listsused to be), so use valuemethod instead.

编辑：不推荐使用5.1版pluck，因为5.2 版它的含义完全不同（和lists以前一样），所以改用value方法。

---

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You're trying to get property of the array, so obviously you're getting error.

您正在尝试获取数组的属性，因此显然您遇到了错误。

If you need single field only, then use pluck(which returns single value - string by default):

如果您只需要单个字段，则使用pluck（默认返回单个值 - 字符串）：

// let's assume user_id is 5

DB::table('attendances')
  ->where('date_only', '=', $newdate)
  ->orderBy('logon','asc')
  ->pluck('user_id');  // "5"

When you need whole row, then first(which returns stdObject):

当您需要整行时，则first（返回 stdObject）：

$att = DB::table('attendances')
  ->where('date_only', '=', $newdate)
  ->orderBy('logon','asc')
  ->first();

$att->user_id; // "5"
$att->any_other_column;

And getis when you want multiple results (which returns simple array of stdObjects):

并且get是当您想要多个结果（返回简单的 stdObjects 数组）时：

$result = DB::table('attendances')
  ->where('date_only', '=', $newdate)
  ->orderBy('logon','asc')
  ->get();

$result; // array(0 => stdObject {..}, 1 => stdObject {..}, ...)
$result[0]->user_id; // "5"

回答by Слаффка Островский

That's for Laravel 5.3:

这是 Laravel 5.3：

$user_id = DB::table('attendances')->select('user_id')->where('date_only', '=', $newdate)->orderBy('logon','asc')->value('user_id');

回答by Vinil Vinayan

This will return user_id only

这将仅返回 user_id

$myquery = DB::table('attendances')->where('date_only', $newdate)->select('user_id')->pluck('user_id')->first();

回答by S Debasish Nayak

To get only the list of value of a single column you can do like this.

要仅获取单个列的值列表，您可以这样做。

$result = CustomerInfo::select('eventDate')->pluck('eventDate');

here $result will give you the result like this:

这里 $result 会给你这样的结果：

["2019-03-25","2020-03-31","2019-03-31","2019-04-24","2019-11-26"]

hope it may help someone

希望它可以帮助某人

回答by 17K

According to the latest documentation: 5.6

根据最新文档：5.6

DB::table('users')->select('name');

will do the trick.

会做的伎俩。

回答by Ankit Vishwakarma

I think there is some confusion; but I am using Laravel 5.3 and pluck and value function is not deprecated as depicted above.

我认为有些混乱；但我使用的是 Laravel 5.3 并且 pluck 和 value 函数没有被弃用，如上所示。

For more clarification: pluck()will be used instead of get()when you want all the values only value()will be used instead of first()when you want only one value.

更多说明： 当您想要所有值时，将使用pluck()而不是get()当您只想要一个值时，仅使用 value()而不是first()。

use method all()to get the array of itmes. usage:

使用方法all()获取项目数组。用法：

\App\User::whereIn('mobile',['971700000', '965000000'])->select('id')->pluck('id')->all();

回答by NIDHINgL

DB::table('table_name')->select('column_na')->get();

DB::table('table_name')->select('column_na')->get();

回答by Lonac Lonac

If you have data in array already and you want to filter only such kind of data, you can do this as well

如果您已经在数组中有数据并且只想过滤此类数据，您也可以这样做

  0 => "first_name"
  1 => "middle_name"
]


$users_data = User::where('id', '1')->get($filter_data );
return $users_data; ```

<pre> In laravel 5.4 works perfect for me </pre>

回答by itachi

 $myquery = DB::table('attendances')->select('user_id')
            ->where('date_only', '=', $newdate)->orderBy('logon','asc')->get();

by default, the returned data will be array of objects. you need to loop over it.

默认情况下，返回的数据将是对象数组。你需要遍历它。

e.g.

例如

foreach($myquery as $i)
{
    echo $i->user_id;
}