2

I have the following table in my database:

    id    |    reference    |    secondID    
---------------------------------------------
    1     |        11       |      1
    2     |        12       |      1
    3     |        12       |      2
    4     |        13       |      1
    5     |        13       |      2
    6     |        13       |      3

And I want to get the max secondID for each reference, so I'm doing the next SQL query:

SELECT *, MAX(secondID) FROM TABLE_A WHERE 1 GROUP BY REFERENCE

If i do this query directly into database through phpMyAdmin I get what I expected:

    id    |    reference    |    secondID    
---------------------------------------------
    1     |        11       |      1
    3     |        12       |      2
    6     |        13       |      3

The problem is that I don't get the same result when doing this in PHP since I only get one row returned insted of three

(here's some code for the query)

$sql = "SELECT *, MAX(secondID) FROM TABLE_A WHERE 1 GROUP BY REFERENCE";
$this->result = $this->db->prepare($sql);

$confirmation = $this->result->execute();

if ($this->result->errorCode() != 0)
{
    $errors = $this->result->errorInfo();
    print_r($errors);
}

if ($confirmation)
{
    return $this->result;
}

return $confirmation;

(and here how I get the data)

$row_number = 0;
while ($data = $db_resource->fetch(PDO::FETCH_ASSOC))
{
    echo $row_number . '<br />';
    $row_number++;
}

I know that if I get rid of 'MAX' and 'GROUP BY' I get more than one row in PHP but I don't understand why this is happening with those statements.

Any advice I could take?

SOLUTION
After some code revision on my part I found that while the SQL query I print to debug code is correct and works as expected it doesn't occur in PHP due to a bad assign order on bindValue() instructions that for some reason gets unnoticed.

I haven't put that code in the question for clarity sake and because is a heavy chunk of code, so sorry for losing everyones time on that question and thanks to responses.

4

2 に答える 2

0

私の側でいくつかのコードを修正した後、コードをデバッグするために出力したSQLクエリは正しく、期待どおりに機能しますが、何らかの理由でbindValue（）命令の割り当て順序が間違っているため、PHPでは発生しないことがわかりました。

わかりやすくするためにそのコードを質問に入れていません。コードの塊が重いため、その質問に時間を費やして申し訳ありません。回答に感謝します。

于 2013-05-24T09:33:16.430 に答える