How to Determine Which Database Is Selected
After Calling Mysql_Select_Db to Grab a Database, Is There Any Way to Later Output the Name of the Database That Is Currently Selected? This Seems Very Basic...
After calling mysql_select_db to grab a database, is there any way to later output the name of the database that is currently selected? This seems very basic but I couldn't find anything on php.net or stackoverflow (all results are for "no database selected").
8 Answers
Just use mysql_query (or mysqli_query, even better, or use PDO, best of all) with:
SELECT DATABASE() FROM DUAL;
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Addendum:
There is much discussion over whether or not FROM DUAL should be included in this or not. On a technical level, it is a holdover from Oracle and can safely be removed. If you are inclined, you can use the following instead:
SELECT DATABASE();
That said, it is perhaps important to note, that while FROM DUAL does not actually do anything, it is valid MySQL syntax. From a strict perspective, including braces in a single line conditional in JavaScript also does not do anything, but it is still a valid practice.
SELECT DATABASE();
p.s. I didn't want to take the liberty of modifying @cwallenpoole's answer to reflect the fact that this is a MySQL question and not an Oracle question and doesn't need DUAL.
You can always use STATUS command to get to know Current database & Current User
In the comments of I found this one from ericpp % bigfoot.com:
If you just need the current database name, you can use MySQL's SELECT DATABASE() command:
<?php
function mysql_current_db() {
$r = mysql_query("SELECT DATABASE()") or die(mysql_error());
return mysql_result($r,0);
}
?>
SELECT DATABASE() worked in PHPMyAdmin.
Another way for filtering the database with specific word.
SHOW DATABASES WHERE `Database` LIKE '<yourDatabasePrefixHere>%'
or
SHOW DATABASES LIKE '<yourDatabasePrefixHere>%';
Example:
SHOW DATABASES WHERE `Database` LIKE 'foobar%'
foobar_animal
foobar_humans_gender
foobar_objects
@mysql_result(mysql_query("SELECT DATABASE();"),0)
If no database selected, or there is no connection it returns NULL otherwise the name of the selected database.
slightly off-topic (using the CLI instead of PHP), but still worth knowing: You can set the prompt to display the default database by using any of the following
mysql --prompt='\d> '
export MYSQL_PS1='\d> '
or once inside
prompt \d>\_
\R \d>\_
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
