Difference between even version and odd version of mysql database

The difference between even version and odd version of mysql database lies in the naming rules of database and the primary key of data table.

1. The naming rules of databases are different: odd-numbered databases are named in singular form, such as "user", and even-numbered databases are named in plural form, such as "user".

2. The naming rules of data table primary keys are different: odd-numbered data table primary keys are named with "id", and even-numbered data table primary keys are named with "table name _id", such as "user _id".