In some situations its useful to use this function for changing databases in general. We've tested it in production environment and it seams to be faster with switching databases than creating new connections.
mysqli::select_db
mysqli_select_db
(PHP 5)
mysqli::select_db -- mysqli_select_db — Selects the default database for database queries
Açıklama
Nesne yönelimli kullanım
$dbname
)Yordamsal kullanım
Selects the default database to be used when performing queries against the database connection.
Bilginize:
This function should only be used to change the default database for the connection. You can select the default database with 4th parameter in mysqli_connect().
Değiştirgeler
-
bağlantı -
Sadece yordamsal tarz: mysqli_connect() veya mysqli_init() işlevinden dönen bir bağlantı tanıtıcısı.
-
dbname -
The database name.
Dönen Değerler
Başarı durumunda TRUE, başarısızlık durumunda FALSE döner.
Örnekler
Örnek 1 mysqli::select_db() example
Nesne yönelimli kullanım
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* return name of current default database */
if ($result = $mysqli->query("SELECT DATABASE()")) {
$row = $result->fetch_row();
printf("Default database is %s.\n", $row[0]);
$result->close();
}
/* change db to world db */
$mysqli->select_db("world");
/* return name of current default database */
if ($result = $mysqli->query("SELECT DATABASE()")) {
$row = $result->fetch_row();
printf("Default database is %s.\n", $row[0]);
$result->close();
}
$mysqli->close();
?>
Yordamsal kullanım
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "test");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* return name of current default database */
if ($result = mysqli_query($link, "SELECT DATABASE()")) {
$row = mysqli_fetch_row($result);
printf("Default database is %s.\n", $row[0]);
mysqli_free_result($result);
}
/* change db to world db */
mysqli_select_db($link, "world");
/* return name of current default database */
if ($result = mysqli_query($link, "SELECT DATABASE()")) {
$row = mysqli_fetch_row($result);
printf("Default database is %s.\n", $row[0]);
mysqli_free_result($result);
}
mysqli_close($link);
?>
Yukarıdaki örneklerin çıktısı:
Default database is test. Default database is world.
Ayrıca Bakınız
- mysqli_connect() - Takma Adı: mysqli::__construct
- mysqli_real_connect() - Opens a connection to a mysql server
