MySQL Implementation rownum method

1. Statement: SELECT @rownum: [email protected]+1 as rownum, orderstate.*
From (SELECT @rownum: =0) R, Orderstate;

Execution Result:

2. Revelation: Through this operation I am more aware that the view is the use of SQL queries using similar outer joins, or the above statements and other similar ways to query the data presented, we found that the view is a consolidation or presentation of multiple tables, through the view cannot directly change the database data.

3. General Enquiry:

4. Joint query:

MySQL Implementation rownum method