MySQL：确定选择哪个数据库？
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MySQL: determine which database is selected?
提问by andrewtweber
After calling mysql_select_dbto 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").
调用mysql_select_db抓取数据库后，有没有什么方法可以稍后输出当前选中的数据库名称？这看起来很基本，但我在 php.net 或 stackoverflow 上找不到任何东西（所有结果都是“没有选择数据库”）。
回答by cwallenpoole
Just use mysql_query (or mysqli_query, even better, or use PDO, best of all) with:
只需使用 mysql_query （或 mysqli_query，甚至更好，或使用 PDO，最好的）与：
SELECT DATABASE() FROM DUAL;
Addendum:
附录：
There is much discussion over whether or not FROM DUALshould 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:
关于是否FROM DUAL应该包括在其中的讨论很多。在技术层面上，它是 Oracle 的遗留物，可以安全地删除。如果您愿意，可以改用以下内容：
SELECT DATABASE();
That said, it is perhaps important to note, that while FROM DUALdoes not actually doanything, 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.
也就是说，可能需要注意的是，虽然FROM DUAL实际上并没有做任何事情，但它是有效的 MySQL 语法。从严格的角度来看，在 JavaScript 中将大括号包含在单行条件中也没有任何作用，但它仍然是一种有效的做法。
回答by Elijah Lynn
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.
ps 我不想冒昧地修改@cwallenpoole 的答案以反映这是一个 MySQL 问题而不是 Oracle 问题并且不需要DUAL.
回答by Mogli
You can always use STATUS command to get to know Current database & Current User
您可以随时使用 STATUS 命令来了解当前数据库和当前用户
回答by Jan Thom?
In the comments of http://www.php.net/manual/de/function.mysql-db-name.phpI found this one from ericpp % bigfoot.com:
在http://www.php.net/manual/de/function.mysql-db-name.php的评论中，我从 ericpp % bigfoot.com 找到了这个：
If you just need the current database name, you can use MySQL's SELECT DATABASE() command:
如果你只需要当前的数据库名称，你可以使用 MySQL 的 SELECT DATABASE() 命令：
<?php
function mysql_current_db() {
$r = mysql_query("SELECT DATABASE()") or die(mysql_error());
return mysql_result($r,0);
}
?>
回答by Jan Thom?
@mysql_result(mysql_query("SELECT DATABASE();"),0)
If no database selected, or there is no connection it returns NULLotherwise the name of the selected database.
如果没有选择数据库，或者没有连接，则返回NULL所选数据库的名称。
回答by Jeff
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
稍微偏离主题（使用 CLI 而不是 PHP），但仍然值得了解：您可以使用以下任何一种方式设置提示以显示默认数据库
mysql --prompt='\d> '
export MYSQL_PS1='\d> '
or once inside
或一旦进入
prompt \d>\_
\R \d>\_
回答by Dexter
Another way for filtering the database with specific word.
另一种用特定词过滤数据库的方法。
SHOW DATABASES WHERE `Database` LIKE '<yourDatabasePrefixHere>%'
or
SHOW DATABASES LIKE '<yourDatabasePrefixHere>%';
Example:
例子：
SHOW DATABASES WHERE `Database` LIKE 'foobar%'
foobar_animal
foobar_humans_gender
foobar_objects
回答by Abhi Chavda
SELECT DATABASE()worked in PHPMyAdmin.
SELECT DATABASE()在 PHPMyAdmin 工作。
