mysqli::select_db

mysqli_select_db

(PHP 5, PHP 7)

mysqli::select_db -- mysqli_select_dbSelects the default database for database queries

설명

객체 기반 형식

bool mysqli::select_db ( string $dbname )

절차식 형식

bool mysqli_select_db ( mysqli $link , 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().

인수

link

순차 형식 전용: mysqli_connect()mysqli_init()가 반환한 연결 식별자.

dbname

The database name.

반환값

성공 시 TRUE를, 실패 시 FALSE를 반환합니다.

예제

Example #1 mysqli::select_db() example

객체 기반 형식

<?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();
?>

절차식 형식

<?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);
?>

위 예제들의 출력:

Default database is test.
Default database is world.

참고

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User Contributed Notes 2 notes

up
-13
hwalker1 at btopenworld dot com
7 years ago
Note that in the second example, if the database "world" does not exist, the database selected does not change. You may need to add additional code to ensure that you are connected to the correct database.
up
-15
pjasiulewicz at gmail dot com
10 years ago
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.
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