一次性轻松查询Oracle所有库的方法分享！（oracle查询所有库）

中文：

在工作中难免会遇到需要查询Oracle所有库的需求，有时查询Oracle数据库中存在的所有库也会很困难，而且官方提供的查询方式也并不太便捷。下面我们就来分享一种轻松查询Oracle所有库的办法，如果有需求可以借鉴或参考下。

首先，我们可以使用以下SQL语句来查询某个Oracle所有库：

SELECT TABLESPACE_NAME FROM SYS.DBA_TABLESPACES;

这条语句会查询某个Oracle实例所定义的所有数据库，可以得到这些数据库的名称，以及它们的存储位置。

除此之外，我们也可以使用以下SQL语句来查询库的属性：

SELECT * FROM SYS.DBA_TABLESPACES_USAGE;

可以使用上述语句查询每个库的大小，数据量，是否存在空闲空间等。

最后，如果我们想要查询某个数据库中所有表的信息，可以使用以下SQL语句：

SELECT TABLESPACE_NAME, TABLE_NAME, STATUS FROM SYS.DBA_TABLES WHERE TABLESPACE_NAME = ”;

在上述语句中，是指待查询的数据库名，可以通过替换得到对应的表名以及表的状态。

总之，上述的这三条SQL语句可以帮助我们方便的查询某个Oracle实例中所有数据库，以及某个库中所有表的信息，可以说真正实现了一次性轻松查询Oracle。

English：

In work, it is inevitable to sometimes need to query all databases in Oracle, sometimes it is difficult to query all the databases in Oracle, and the query methods provided by the official are not very convenient. Now, let’s share a way to easily query all databases in Oracle, if there is a demand, you can refer to it.

First of all, we can use the following SQL statement to query all databases in a certain Oracle instance:

SELECT TABLESPACE_NAME FROM SYS.DBA_TABLESPACES;

This statement will query all databases defined in a certain Oracle instance to get their names and locations.

In addition, we can also use the following SQL statement to query the properties of the databases:

SELECT * FROM SYS.DBA_TABLESPACES_USAGE;

You can use the above statement to query the size, data volume, presence of free space, etc. of each database.

Finally, if we want to query the information of all tables in a certain database, we can use the following SQL statement:

SELECT TABLESPACE_NAME, TABLE_NAME, STATUS FROM SYS.DBA_TABLES WHERE TABLESPACE_NAME = ”;

In the above statement, refers to the name of the database to be queried, and the corresponding table name and table status can be obtained by replacement.

In conclusion, the above three SQL statements can help us easily query all databases in a certain Oracle instance and all the tables in a certain database, which can be said to truly achieve one-stop easy query of Oracle.