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 — Executes a prepared Query
Descrierea
Stil obiect-orientat
public mysqli_stmt::execute
(
) : bool
Stil procedural
Executes a query that has been previously prepared using the mysqli_prepare() function. When executed any parameter markers which exist will automatically be replaced with the appropriate data.
If the statement is UPDATE, DELETE,
or INSERT, the total number of affected rows can be
determined by using the mysqli_stmt_affected_rows()
function. Likewise, if the query yields a result set the
mysqli_stmt_fetch() function is used.
Notă:
When using mysqli_stmt_execute(), the mysqli_stmt_fetch() function must be used to fetch the data prior to performing any additional queries.
Parametri
-
stmt -
Numai stilul procedural: Un identificator al declarației întors de mysqli_stmt_init().
Valorile întoarse
Întoarce valoarea true în cazul
succesului sau false în cazul eșecului.
Exemple
Example #1 Stil obiect-orientat
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query("CREATE TABLE myCity LIKE City");
/* Prepare an insert statement */
$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';
/* Execute the statement */
$stmt->execute();
$val1 = 'Bordeaux';
$val2 = 'FRA';
$val3 = 'Aquitaine';
/* Execute the statement */
$stmt->execute();
/* close statement */
$stmt->close();
/* retrieve all rows from myCity */
$query = "SELECT Name, CountryCode, District FROM myCity";
if ($result = $mysqli->query($query)) {
while ($row = $result->fetch_row()) {
printf("%s (%s,%s)\n", $row[0], $row[1], $row[2]);
}
/* free result set */
$result->close();
}
/* remove table */
$mysqli->query("DROP TABLE myCity");
/* close connection */
$mysqli->close();
?>
Example #2 Stil procedural
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
mysqli_query($link, "CREATE TABLE myCity LIKE City");
/* Prepare an insert statement */
$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';
$val3 = 'Baden-Wuerttemberg';
/* Execute the statement */
mysqli_stmt_execute($stmt);
$val1 = 'Bordeaux';
$val2 = 'FRA';
$val3 = 'Aquitaine';
/* Execute the statement */
mysqli_stmt_execute($stmt);
/* close statement */
mysqli_stmt_close($stmt);
/* retrieve all rows from myCity */
$query = "SELECT Name, CountryCode, District FROM myCity";
if ($result = mysqli_query($link, $query)) {
while ($row = mysqli_fetch_row($result)) {
printf("%s (%s,%s)\n", $row[0], $row[1], $row[2]);
}
/* free result set */
mysqli_free_result($result);
}
/* remove table */
mysqli_query($link, "DROP TABLE myCity");
/* close connection */
mysqli_close($link);
?>
Exemplele de mai sus vor afișa:
Stuttgart (DEU,Baden-Wuerttemberg) Bordeaux (FRA,Aquitaine)
A se vedea și
- mysqli_prepare() - Prepare an SQL statement for execution
- mysqli_stmt_bind_param() - Binds variables to a prepared statement as parameters
- mysqli_stmt_get_result() - Gets a result set from a prepared statement
add a note
User Contributed Notes 2 notes
Typer85 at gmail dot com ¶
17 years ago
andrey at php dot net ¶
19 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.
