mysqli
PHP Manual

mysqli_select_db

mysqli->select_db()

(PHP 5)

mysqli->select_db() — Selects the default database for database queries

说明

Procedural style:

bool mysqli_select_db ( mysqli $link , string $dbname )

Object oriented style (method):

mysqli
bool select_db ( string $dbname )

Selects the default database to be used when performing queries against the database connection.

Note: 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().

参数

link

Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()

dbname

The database name.

返回值

如果成功则返回 TRUE,失败则返回 FALSE

范例

Example#1 Object oriented style

<?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();
?>

Example#2 Procedural style

<?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);
?>

上例将输出:

Default database is test.
Default database is world.

参见


mysqli
PHP Manual