mysqli::savepoint
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
Descrierea
Stil obiect-orientat
bool mysqli::select_db
( string
$dbname
)Stil procedural
Selects the default database to be used when performing queries against the database connection.
Notă:
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().
Parametri
-
link -
Numai stilul procedural: Un identificator al legăturii întors de mysqli_connect() sau mysqli_init()
-
dbname -
The database name.
Valorile întoarse
Întoarce valoarea TRUE în cazul
succesului sau FALSE în cazul eșecului.
Exemple
Example #1 mysqli::select_db() example
Stil obiect-orientat
<?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();
?>
Stil procedural
<?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);
?>
Exemplele de mai sus vor afișa:
Default database is test. Default database is world.
Vedeți de asemenea
- mysqli_connect() - Pseudonim pentru mysqli::__construct
- mysqli_real_connect() - Opens a connection to a mysql server
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User Contributed Notes
mysqli::select_db - [1 notes]
pjasiulewicz at gmail dot com ¶
2 years ago