MySQL database

Data addition, deletion and modification

Data addition, deletion and modification

Addition, deletion and modification (CURD)
- C: Create【Create】
- U: Update【Update】
- R: Read【Retrieve】
- D: Delete【Delete】

format:INSERT INTO table_name (column_name1,column_name2,...) VALUES(VALUE1,VALUE2,...)

Note: The primary key column grows automatically, but it needs to occupy the position when inserting the whole column. Usually 0 or default or null is used to occupy the position. After the insertion is successful, the actual data shall prevail.
Full column insertion: the order of the values corresponds to the order of the fields in the table

insert into 表名 values(...)
例：
insert into students values('张三',18,'上海市浦东区','2000-1-2');

Partial column (field) insertion: the order of the values corresponds to the order of the given columns

insert into 表名(列1,...) values(值1,...)
例：
insert into students(name,hometown,birthday) values('李四','上海杨浦区','2001-3-2');

The above statement can insert one row of data into the table at a time, and it can also insert multiple rows of data at one time, which can reduce the communication with the database
Full column multi-row insertion: the order of the values corresponds to the order of the given columns

insert into 表名 values(...),(...)...;
例：
insert into classes values(0,'文科班'),(0,'理科班');

insert into 表名(列1,...) values(值1,...),(值1,...)...;
例：
insert into students(name) values('张三'),('李四'),('王五');

delete from 表名 where 条件
例：
delete from students where id=5;

update students set isdelete=1 where id=1;

format:UPDATE tasble_name SET column_name1=VALUE1, column_name2=VALUE2,... where 条件判断

update 表名 set 列1=值1,列2=值2... where 条件
例：
update students set birthday='2001-3-2',hometown='上海宝山区' where name='张三';

select * from 表名;
例：
select * from students;

select 列1,列2,... from 表名;
例：
select id,name as 姓名，age as 年龄，hometown as 家庭住址 from students;

mysqldump –uroot –p 数据库名 > python.sql;

# 按提示输入mysql的密码

mysql -uroot –p 新数据库名 < python.sql

# 根据提示输入mysql密码