Php 计数在Laravel查询生成器中未按预期工作
我正在尝试获取数据库中有多少个名称。为此,我使用的查询生成器如下所示:Php 计数在Laravel查询生成器中未按预期工作,php,sql,laravel,count,laravel-query-builder,Php,Sql,Laravel,Count,Laravel Query Builder,我正在尝试获取数据库中有多少个名称。为此,我使用的查询生成器如下所示: $namesIdsCount = DB::table('names_to_options') ->select('name_id') ->groupBy('name_id') ->havingRaw($having) ->count(); $namesIdsCount = DB::table('names_to_options') ->select('n
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->count();
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get();
+---------------+---------+
| aggregate | name_id |
+---------------+---------+
| 24 | 1 |
+---------------+---------+
| 5 | 2 |
+---------------+---------+
| 30 | 3 |
+---------------+---------+
| ... and so on | 4 |
+---------------+---------+
SELECT COUNT(*) FROM (
SELECT
`name_id`
FROM `names_to_options`
WHERE EXISTS(
{your $havingRaw sub-query}
)
GROUP BY `name_id`
) AS temp;
是说24,这是不正确的,因为如果我写这样的代码:
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->count();
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get();
+---------------+---------+
| aggregate | name_id |
+---------------+---------+
| 24 | 1 |
+---------------+---------+
| 5 | 2 |
+---------------+---------+
| 30 | 3 |
+---------------+---------+
| ... and so on | 4 |
+---------------+---------+
SELECT COUNT(*) FROM (
SELECT
`name_id`
FROM `names_to_options`
WHERE EXISTS(
{your $havingRaw sub-query}
)
GROUP BY `name_id`
) AS temp;
结果对象包含247个元素,这是正确的。我尝试过使用skip/take,但仍然没有结果。我错在哪里?谢谢你的帮助。Inuyaki是对的
(身份证、姓名和身份证)
(1,1)
(2,1)
(3,2)
(4,3)
共有四行,因此get()方法将返回4行
但是如果使用groupBy[name\u id],则有三个组
1(1,1)
2(2)
3(3)
现在计数将返回3
希望这会有所帮助。我认为情况正好相反,你没有得到24个小组。第一组中有24个元素。该配置将导致以下查询:
SELECT
COUNT(*) AS 'aggregate',
`name_id`
FROM `names_to_options`
WHERE EXISTS(
{your $havingRaw sub-query}
)
GROUP BY `name_id`;
您最终得到的结果将如下所示:
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->count();
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get();
+---------------+---------+
| aggregate | name_id |
+---------------+---------+
| 24 | 1 |
+---------------+---------+
| 5 | 2 |
+---------------+---------+
| 30 | 3 |
+---------------+---------+
| ... and so on | 4 |
+---------------+---------+
SELECT COUNT(*) FROM (
SELECT
`name_id`
FROM `names_to_options`
WHERE EXISTS(
{your $havingRaw sub-query}
)
GROUP BY `name_id`
) AS temp;
Query\Builder
只是没有意识到当涉及到count()
时,可以返回多个结果
不过你自己也很接近正确答案
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get();
get()。所以你的答案是:
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get()
->count();
如果您真的希望在MySQL中发生这种情况,那么您希望发生的查询如下所示:
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->count();
$namesIdsCount = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having)
->get();
+---------------+---------+
| aggregate | name_id |
+---------------+---------+
| 24 | 1 |
+---------------+---------+
| 5 | 2 |
+---------------+---------+
| 30 | 3 |
+---------------+---------+
| ... and so on | 4 |
+---------------+---------+
SELECT COUNT(*) FROM (
SELECT
`name_id`
FROM `names_to_options`
WHERE EXISTS(
{your $havingRaw sub-query}
)
GROUP BY `name_id`
) AS temp;
为此,您可以执行以下操作:
$query = DB::table('names_to_options')
->select('name_id')
->groupBy('name_id')
->havingRaw($having);
$sql = $query->toSql();
$values = $query->getBindings();
$count = DB::table(DB::raw('('.$sql.') AS `temp`'))
->selectRaw("COUNT(*) AS 'aggregate'", $values)
->first()
->aggregate;
当要求MySQL编写这样的临时表时,它的性能可能会有点不稳定,因此您必须进行实验,看看哪个选项更快。having
$having的值是什么?@Jerodev它包含我自定义的sql语句,比如SUM(CASE when option_id IN({$optionSql}),然后1 ELSE 0 END)>0和SUM(CASE when option_id IN IN.)({$optionSql})然后1 ELSE 0 END)>0
,其中,$optionSql
是一个ID用coma分隔的字符串。首先使用get()方法运行查询,然后对$namesidscont集合中的值进行计数,即count($namesidscont)我的第一个猜测是groupBy会产生24个组,Ali说,计数是多少($namesidscont)这是绝对正确的,非常感谢你向我解释!