Basic sentence format for inserting data, modifying data, deleting data in MySQL

First of all, the relational database management system will check whether the defined integrity rules are destroyed when executing insert, modify, delete statements,
including: entity integrity, referential integrity, user-defined integrity (not null constraints, unique constraints, values Domain constraints).
1. Insert data:

insert into 表名···values()···;

• insert into table name values ​​("", "", ···);
  insert an entire tuple;

• insert into table name attribute column 1, attribute column 2, attribute column 3, ... values ​​("attribute value 1", "attribute value 2", "attribute value 3", ···);
  insert individual attribute values, other The attribute value defaults to null;

• insert into subquery; insert
  the results of the subquery into the table;
  Note: The target column of the subquery must match the into clause, including the number and type of target columns.
  Example:
  insert into Student (Sdept, Sgrade)
  select Sdept, Sgrade
  from Student
  group by Sdept;
  (Sdept and Sgrade here correspond one-to-one with the target column selected in the subquery)

2. Modify the data:

update 表名 set···；

• update table name set column name = expression, ··· where ···;

  Example: update student set Sage = 22 where Sno = "201215121";
  change the age of the student with the student number 201215121 to 22.

• update table name set an attribute name = the attribute name + n;
  add n to all information data in the attribute;

  Example: update table name set Sage = Sage + n;
  increase the age of all students by 10;

• Similarly, the object of modifying data can also be the result of a subquery, and the requirements are also consistent.

3. Delete data:

delete from 表名 where ···；

• delete from Student where Sno = “201215121”;
  delete all records of students with student number 201215121;
• delete from Student;
  delete all the information in the Student table;
• Delete statement with subquery.