通過phpmyadmin測試時，SQL查詢工作正常，但在PHP PDO中嘗試相同操作時失敗

Question

好的，從另一個用戶的問題上，我有以下查詢：

set @test = 0, @id=0, @count=0;
select m.id, max(count)
from (
select 
 @count := if(TookTest = 1 and PatientID = @id, @count+1, 0) as count,
 @test := Tooktest,
 @id := PatientID as id
from medical) as m
group by m.id
having max(count) >=2;

這在phpmyadmin中工作正常，但是當我在PDO語句中嘗試相同時，它失敗並顯示以下錯誤消息：

PDOException：SQLSTATE [HY000]：一般錯誤

$sql="set @test = 0, @id=0, @count=0;
select m.id, max(count)
from (
select 
 @count := if(TookTest = 1 and PatientID = @id, @count+1, 0) as count,
 @test := Tooktest,
 @id := PatientID as id
from medical) as m
group by m.id
having max(count) >=2;";

try{
    $stmt=$dbh->prepare($sql);
    if ($stmt->execute()){
        $rows=$stmt->fetchall();
    }
}catch(PDOException $s){
    echo $s;
}

我是否缺少某些東西，例如無法在PDO語句中設置變量？

Answer 1

同樣，它不是設置變量，而是它試圖同時運行兩個查詢的問題。 所以我需要將上面的代碼更改為此：

$sql="set @test = 0, @id=0, @count=0;";
try{
    $stmt=$dbh->prepare($sql);
    $stmt->execute()
}catch(PDOException $s){
    echo $s;
}

$sql="select m.id, max(count)
from (
select 
 @count := if(TookTest = 1 and PatientID = @id, @count+1, 0) as count,
 @test := Tooktest,
 @id := PatientID as id
from medical) as m
group by m.id
having max(count) >=2;";

try{
    $stmt=$dbh->prepare($sql);
    if ($stmt->execute()){
        $rows=$stmt->fetchall();
    }
}catch(PDOException $s){
    echo $s;
}

Answer 2

那兩個查詢

set @test = 0, @id=0, @count=0;
select m.id, max(count)
from (
select 
 @count := if(TookTest = 1 and PatientID = @id, @count+1, 0) as count,
 @test := Tooktest,
 @id := PatientID as id
from medical) as m
group by m.id
having max(count) >=2;

可以被當作一個查詢，所以只需要一個prepere語句

  select m.id, max(count)
    from (
    select 
     @count := if(TookTest = 1 and PatientID = @id, @count+1, 0) as count,
     @test := Tooktest,
     @id := PatientID as id
    from medical) as m
    cross join ( select @test := 0, @id := 0, @count = :0 ) as init_user_params
    group by m.id
    having max(count) >=2;