Question

好的here上的其他用户问题我有以下问题：

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;

这在phpmyadmin中运行正常，但是当我在PDO语句中尝试相同时，它会失败并显示以下错误消息：

PDOException：SQLSTATE [HY000]：常规错误

$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;
}

我是否缺少这样的东西，就像你无法在PDO语句中设置变量一样？

Answer 1

同样，它不是设置变量，而是它试图同时运行两个查询的问题。所以我需要将上面的代码更改为：

$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

这两个查询

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;

可以重新命名为一个查询，因此您只需要一个预备语句

  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;

通过phpmyadmin进行测试时SQL查询工作正常，但在PHP PDO中尝试相同的操作时失败

2 个答案: