PHP MYSQL - 合并来自另一个变量的查询

Question

请问我是否可以合并来自不同变量的查询，或者是否有任何其他方式。我想将 $query_1 插入到 $query_2

示例:

$sql = "SELECT l_id from mlk";
$result = mysqli_query($conn, $sql);
$count = mysqli_num_rows($result); 

if (mysqli_num_rows($result) > 0) {
    while($row = mysqli_fetch_assoc($result)) {
        $l_id[] = $row["l_id"];
     }
}

mysqli_free_result($result);

foreach($l_id as $row){
    $query_1= "(select count(*) from staff s where s.l_id = $row) as mlk_$row,";
}

$query_2= "SELECT mlk.lokasi,
//insert $query_1 here  
from mlk INNER JOIN staff WHERE staff.l_id=mlk.l_id GROUP BY mlk.lokasi";
$result = mysqli_query($conn, $sql);

1. mlk 是一个存储人员工作地点的表
2. $query_2 将显示位置名称，我还想显示该特定位置的员工总数。例如，吉隆坡，10

Answer 1

只在第二个查询中包含计数:

SELECT mlk.lokasi, count(*) as no_of_staff 
from mlk
INNER JOIN staff on staff.l_id=mlk.l_id
GROUP BY mlk.lokasi

我还通过将连接条件从 where 子句移动到 on 子句，将隐式连接更改为显式连接。