Java novice learning 2021-2-25 record the daily learning content (if there is any infringement, please contact to delete!!!) [Mysql (1)]

2021-2-25

1. Basic concepts of database

2. Database, data table, data relationship

3. Introduction to Sql

4. Database query and creation

5. Modify and delete the database (DDL)

6. Query, create, modify, and delete data tables

7. Add table data, modify, delete (DML)

8. Introduction to query syntax

9. Query of DQL table data (select, ifnull)

SELECT
`name`,
-- 如果英语成绩为空，则用语文成绩代替
IFNULL(english,chinese)
FROM
student

10. Query of DQL table data-conditional query

11.DQL table data query-aggregate function query

12.DQL table data query-sort query

13.DQL table data query-group query

14.DQL table data query-paging query