One SQL statement queries multiple databases and multiple SQL statements

One SQL statement queries multiple databases and multiple SQL statements

Requirement: An SQL statement is used to query the associated results from multiple databases and output them to the client.

Investigation: The spring framework can configure multiple data sources. SQL can also attach multiple databases to a primary database.

Solution: UseATTACH DATABASEStatement to add multiple databases to the master database.

Syntax:

Attach database 'databasename 'As 'Alias-name ';

Example:

Attach database 'C: \ Users \ Administrator \ Desktop \ sqlite_data.sq3 'As 'sd ';

Summary

The preceding section describes an SQL statement used to query multiple databases. I hope it will be helpful to you. If you have any questions, please leave a message and I will reply to you in a timely manner. Thank you very much for your support for the help House website!