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mysql_select_dbBir MySQL veritabanı seçer


Bu eklentinin kullanımı PHP 5.5.0 itibariyle önerilmemekte olup PHP 7.0.0'da kaldırılmıştır. Bu eklentinin yerine ya mysqli ya da PDO_MySQL eklentisi kullanılmalıdır. MySQL API seçerken MySQL API'ye Bakış belgesi yardımcı olabilir. Bu işlevin yerine kullanılabilecekler:


mysql_select_db(string $veritabanı_adı, resource $bağlantı_belirteci = null): bool

Belirtilen bağlantı belirteci ile ilişkili sunucuda, geçerli etkin veritabanını ayarlar. Takip eden bütün mysql_query() çağrıları etkin veritabanında yapılacaktır.



Seçilecek veritabanının adı.


MySQL bağlantısı. Eğer bağlantı belirteci belirtilmemişse mysql_connect() tarafından açılan son bağlantı kullanılmaya çalışılır. Eğer böyle bir bağlantı yoksa mysql_connect() değiştirgesiz olarak çağrılmış gibi bir bağlantı oluşturmaya çalışır. Hiçbir bağlantı yoksa ve yenisi de kurulamazsa E_WARNING seviyesinde bir hata üretilir.

Dönen Değerler

Başarı durumunda true, başarısızlık durumunda false döner.


Örnek 1 - mysql_select_db() örneği


if (!
$link) {
'Bağlı değil : ' mysql_error());

// foo'yu geçerli veritabanı yap
$db_selected mysql_select_db('foo'$link);
if (!
$db_selected) {
    die (
'foo kullanılamaz : ' mysql_error());



Geriye uyumluluk adına, kullanımı önerilmese de şu takma ad kullanılabilir: mysql_selectdb()

Ayrıca Bakınız

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User Contributed Notes 8 notes

james at gogo dot co dot nz
17 years ago
Be carefull if you are using two databases on the same server at the same time.  By default mysql_connect returns the same connection ID for multiple calls with the same server parameters, which means if you do

= mysql_connect(...stuff...);
$db2 = mysql_connect(...stuff...);
mysql_select_db('db1', $db1);
mysql_select_db('db2', $db2);

then $db1 will actually have selected the database 'db2', because the second call to mysql_connect just returned the already opened connection ID !

You have two options here, eiher you have to call mysql_select_db before each query you do, or if you're using php4.2+ there is a parameter to mysql_connect to force the creation of a new link.
16 years ago
About opening connections if the same parameters to mysql_connect() are used: this can be avoided by using the 'new_link' parameter to that function.

This parameter has been available since PHP 4.2.0 and allows you to open a new link even if the call uses the same parameters.
8 years ago
function go_mysql($query)
    global $mysql_link;
    if (!$mysql_link)
        $mysql_link = mysql_connect("localhost","root","my_pass") or die(mysql_error());
        mysql_select_db("my_db") or die(mysql_error());
        mysql_query("SET NAMES 'utf8'");
        mysql_query("set character_set_client='utf8'");
        mysql_query("set character_set_results='utf8'");
        mysql_query("set collation_connection='utf8'");
        global $mysql_link;
    if ($result)
        return $result;
        echo "Database Error: " . mysql_error()."<br><b>$query</b>";
anotheruser at example dot com
13 years ago
Cross-database join queries, expanding on Dan Ross's post...

Really, this is a mysql specific feature, but worth noting here.  So long as the mysql user has been given the right permissions to all databases and tables where data is pulled from or pushed to, this will work.  Though the mysql_select_db function selects one database, the mysql statement may reference another (the syntax for referencing a field in another db table being 'database.table.field').


    FROM tblPosts
    LEFT JOIN Users.tblUsers ON AuthorID = Users.tblUsers.UserID
    GROUP BY PostID,AuthorID,Username

$dblink = mysql_connect("somehost", "someuser", "password");
$qry = mysql_query($sql_statement,$dblink);

miloshio at gmail dot com
9 years ago
You can select MySQL database without using this function.
Simply right after connecting to MySQL
<?php $connection = mysql_connect("dabatbasehost", "username", "password"); ?>
perform this query:
<?php mysql_query("USE somedatabase", $connection); ?>
duncan at berrimans dot co dot uk
9 years ago
Note that the manual is slightly misleading it states :-

"Sets the current active database on the server that's associated with the specified link identifier. Every subsequent call to mysql_query() will be made on the active database."

The 2nd statement is not true or at best unclear.

mysql_query() manual entry actually correctly states it will use the last link opened by mysql_connect() by default.

Thus if you have 2 connections you will need to specify the connection when calling mysql_query or issue the connect again to ensure the 1st database becomes the default, simply using mysql_select_db will not make the 1st database the default for subsequent calls to mysql_query.

Its probably only apparent when the two databases are on different servers.
me at khurshid dot com
14 years ago
Problem with connecting to multiple databases within the same server is that every time you do:
mysql_connect(host, username, passwd);
it will reuse 'Resource id' for every connection, which means you will end with only one connection reference to avoid that do:
mysql_connect(host, username, passwd, true);
keeps all connections separate.
riad93 at mail dot ru
12 years ago
You can use DataBases without <?php mysql_select_db() ?>

And you will havenot james at gogo dot co dot nz's problems :)

mysql_query('SELECT * FROM database_name.table_name');

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