MySQL Database Metadata

Database Metadata is basically ‘data about data’. Relational databases store data in the form of tables. Some examples of MySQL relational database metadata are as follows:

• Information about tables in a database, table names, table size, etc.
• Information about columns in the tables, keys like primary key, foreign keys, indexes, etc
• Information about other database objects like stored procedures, triggers, etc.

Obtain Metadata

MySQL server offers two methods for obtaining the database metadata.

• SHOW statements
• INFORMATION_SCHEMA

The SHOW statements are standard MySQL-only feature. The SHOW statements require different statements for retrieving various metadata.

For example, to get the columns and the data types of columns in a table, we can use the following SHOW statement:

mysql> SHOW COLUMNS FROM City;

 

SHOW statements are more concise and are easier to remember.

INFORMATION_SCHEMA

INFORMATION_SCHEMA is a set of metadata usually referred to as database catalog. This is an information database that stores information about other databases on the MySQL server.

This database contains several read-only system views. To know more information about the schema:

https://www.testingdocs.com/mysql-information_schema-database/

 

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MySQL Tutorials

MySQL Tutorials on this website:

https://www.testingdocs.com/mysql-tutorials-for-beginners/