Laravel如何使用查询生成器返回单列值 [英] Laravel how to return single column value using Query Builder

问题描述

我想使用SQL查询中的数据，在这里是我的代码来进一步说明:

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

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

    $myquery->user_id;

现在我希望我的$ myquery的值是USER_ID的值，如果我使用上述代码-$ myquery-> user_id，则会出现错误.

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;

推荐答案

自版本 5.1 pluck起，已弃用，因为 5.2 的含义完全不同(就像lists一样)，所以请改用value方法.

---

您正在尝试获取数组的属性，因此很显然您会遇到错误.

As of version 5.1 pluck is deprecated, since 5.2 its meaning is completely different (as lists used to be), so use value method instead.

---

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

如果仅需要单个字段，则使用pluck(默认情况下返回单个值-字符串):

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

// let's assume user_id is 5

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

当您需要整行时，然后first(返回stdObject):

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

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

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

get是需要多个结果时(返回简单的stdObjects数组):

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

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

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

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