Just to clarify this note in the Manual regarding this function:
"Note: When using mysqli_stmt_execute(), the mysqli_stmt_fetch() function must be used to fetch the data prior to performing any additional queries."
This is because this function DOES NOT store the result set on the client side so you have to fetch everything in the result set or else you risk major errors.
If you however use the function mysqli_stmt_store_result immediately after you use this function, you are forcing the result set to be stored on the client side and thus it is safe to issue extra queries before fetching all the data.
This is where you really have to make a choice regarding on your application's priorities. If you know your result set is memory hefty, then its a good idea not to store it on the client side so you don't run in any errors regarding unavailable memory on the server. But this also means your not going to do a lot of calculations on the result set or else you will prevent any other usage of the table to which the result set came from until you fetched it all.
If your going to do a lot of calculations or your result set is not memory hefty, its probably a good idea to store it on the client side.
Most of these problems can easily be solved if you have a lot of memory available on your server but thats usually not the case for those on shared hosting.
An intelligent way to counter this problem if your on a shared host is to be smart in the way you design your queries. Try to limit the result set if you know you will be fetching memory hefty result sets.
Test different alternatives for your application and see what works best for you under different conditions.
Good Luck,
mysqli_stmt::execute
mysqli_stmt_execute
(PHP 5, PHP 7)
mysqli_stmt::execute -- mysqli_stmt_execute — プリペアドクエリを実行する
説明
オブジェクト指向型
public mysqli_stmt::execute
(
) : bool
手続き型
事前に mysqli_prepare() 関数で用意されたクエリを実行します。 パラメータマーカが存在する場合、その内容は自動的に適切なデータに置き換えられます。
ステートメントが UPDATE、DELETE
あるいは INSERT であった場合、
変更された行の総数は mysqli_stmt_affected_rows()
関数を使用することで取得可能です。同様に、クエリが結果セットを返す場合は
mysqli_stmt_fetch() 関数を使用できます。
注意:
mysqli_stmt_execute() を使用した際には、 他のクエリを実行する前に mysqli_stmt_fetch() 関数を使用する必要があります。
返り値
成功した場合に true を、失敗した場合に false を返します。
例
例1 オブジェクト指向型
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* 接続状況をチェックします */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query("CREATE TABLE myCity LIKE City");
/* insert ステートメントを準備します */
$query = "INSERT INTO myCity (Name, CountryCode, District) VALUES (?,?,?)";
$stmt = $mysqli->prepare($query);
$stmt->bind_param("sss", $val1, $val2, $val3);
$val1 = 'Stuttgart';
$val2 = 'DEU';
$val3 = 'Baden-Wuerttemberg';
/* ステートメントを実行します */
$stmt->execute();
$val1 = 'Bordeaux';
$val2 = 'FRA';
$val3 = 'Aquitaine';
/* ステートメントを実行します */
$stmt->execute();
/* ステートメントを閉じます */
$stmt->close();
/* myCity からすべての行を取得します */
$query = "SELECT Name, CountryCode, District FROM myCity";
if ($result = $mysqli->query($query)) {
while ($row = $result->fetch_row()) {
printf("%s (%s,%s)\n", $row[0], $row[1], $row[2]);
}
/* 結果セットを開放します */
$result->close();
}
/* テーブルを削除します */
$mysqli->query("DROP TABLE myCity");
/* 接続を閉じます */
$mysqli->close();
?>
例2 手続き型
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* 接続状況をチェックします */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
mysqli_query($link, "CREATE TABLE myCity LIKE City");
/* insert ステートメントを準備します */
$query = "INSERT INTO myCity (Name, CountryCode, District) VALUES (?,?,?)";
$stmt = mysqli_prepare($link, $query);
mysqli_stmt_bind_param($stmt, "sss", $val1, $val2, $val3);
$val1 = 'Stuttgart';
$val2 = 'DEU';
$val3 = 'Baden-Wuerttemberg';
/* ステートメントを実行します */
mysqli_stmt_execute($stmt);
$val1 = 'Bordeaux';
$val2 = 'FRA';
$val3 = 'Aquitaine';
/* ステートメントを実行します */
mysqli_stmt_execute($stmt);
/* ステートメントを閉じます */
mysqli_stmt_close($stmt);
/* myCity からすべての行を取得します */
$query = "SELECT Name, CountryCode, District FROM myCity";
if ($result = mysqli_query($link, $query)) {
while ($row = mysqli_fetch_row($result)) {
printf("%s (%s,%s)\n", $row[0], $row[1], $row[2]);
}
/* 結果セットを開放します */
mysqli_free_result($result);
}
/* テーブルを削除します */
mysqli_query($link, "DROP TABLE myCity");
/* 接続を閉じます */
mysqli_close($link);
?>
上の例の出力は以下となります。
Stuttgart (DEU,Baden-Wuerttemberg) Bordeaux (FRA,Aquitaine)
参考
- mysqli_prepare() - 実行するための SQL ステートメントを準備する
- mysqli_stmt_bind_param() - プリペアドステートメントのパラメータに変数をバインドする
- mysqli_stmt_get_result() - プリペアード・ステートメントから結果セットを取得
add a note
User Contributed Notes 3 notes
Typer85 at gmail dot com ¶
14 years ago
vedran-b at email dot htnet dot hr ¶
10 years ago
After the stmt->execute() function is called the variable "$X" that was storing the bind param e.g.
$stmt->bind_param("i", $X);
gets set to 0.
So don't try to use it for something else later... like me ...for $_session key coz you'll get crazy..... like me...
p.s. $_session keys starting with nums get discarded.
andrey at php dot net ¶
15 years ago
If you select LOBs use the following order of execution or you risk mysqli allocating more memory that actually used
1)prepare()
2)execute()
3)store_result()
4)bind_result()
If you skip 3) or exchange 3) and 4) then mysqli will allocate memory for the maximal length of the column which is 255 for tinyblob, 64k for blob(still ok), 16MByte for MEDIUMBLOB - quite a lot and 4G for LONGBLOB (good if you have so much memory). Queries which use this order a bit slower when there is a LOB but this is the price of not having memory exhaustion in seconds.
