1. Metadata concept
Meta (meta) is generally translated by us as "about...".
Meta data (meta data) - "data about data" Data about data, usually structured data (such as data stored in a database, specifying the length and type of fields, etc.).
Metadata is the data that describes the data. In MySQL, it is the data that describes the database.
Which databases are there, which tables each table has, how many fields the table has, what type the fields are, etc. Such data is the metadata of the database.
2. Three ways to obtain metadata
The first: various show;
The second: various select;
The third type: it is a command under the mysql command line, not a sql statement.
3. Commonly used methods of metadata
getDatabaseProductName:获取数据库的产品名称 getDatabaseProductName:获取数据库的版本号 getUserName:获取数据库的用户名 getURL:获取数据库连接的URL getDriverName:获取数据库的驱动名称 driverVersion:获取数据库的驱动版本号 isReadOnly:查看数据库是否只允许读操作 supportsTransactions:查看数据库是否支持事务
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