PHP mysqli: select_db() function
mysqli_select_db() function/ mysqli::select_db
The mysqli_select_db() function/ mysqli::select_db is used to change the default database for the connection.
Syntax:
Object oriented style
bool mysqli::select_db ( string $dbname )
Procedural style
bool mysqli_select_db ( mysqli $link , string $dbname )
Parameter:
| Name | Description | Required/Optional | |
|---|---|---|---|
| link | A link identifier returned by mysqli_connect() or mysqli_init() | Required for procedural style only and Optional for Object oriented style | |
| dbname | The database name. | Required | |
Usage: Procedural style
mysqli_select_db(connection,dbname);
Parameter:
| Name | Description | Required/Optional |
|---|---|---|
| connection | Specifies the MySQL connection to use | Required |
| dbname | Specifies the default database to be used | Required |
Return value:
Returns TRUE on success or FALSE on failure.
Version: PHP 5, PHP 7
Example of object oriented style:
<?php
$mysqli = new mysqli("localhost", "user1", "datasoft123", "hr");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* return name of current default database */
if ($result = $mysqli->query("SELECT DATABASE()")) {
$row = $result->fetch_row();
printf("Default database is %s.\n", $row[0]);
$result->close();
}
/* change db to world db */
$mysqli->select_db("hr");
/* return name of current default database */
if ($result = $mysqli->query("SELECT DATABASE()")) {
$row = $result->fetch_row();
printf("Default database is %s.\n", $row[0]);
$result->close();
}
$mysqli->close();
?>
Output:
Default database is hr. Default database is hr.
Example of the Procedural style
<?php
$link = mysqli_connect("localhost", "user1", "datasoft123", "hr");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* return name of current default database */
if ($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($link, "hr");
/* return name of current default database */
if ($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);
?>
Output:
Default database is hr. Default database is hr.
See also
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