data
1. Insert
INSERT INTO userinfo(id,username,birthday) VALUES (5,'孙七','1982-12-26'),(6,'Jack','1982-11-26');
INSERT INTO userinfo SET id = 7, username = '朱八', birthday = '1992-11-11';
2. Modify
UPDATE userinfo SET username = 'tom' WHERE id = 6;
3. Delete
DELETE FROM userinfo WHERE id = 7;
Empty Table:
TRUNCATE userinfo；
database:
4. Create
create database if not exists database name
The database generally does not modify the name and contents
6. Modify database character set
ALTER DATABASE database name CHARACTER SET gbk (or utf-8)
7. Delete
drop database database name
table:
desc table
View table structure
8. Create:
create table 表名(
Column name Data type 1 [1] constraints,
Column name Data type 2 2 [2] constraints,
Column Name Data Type 3 3 3 [constraints]
);
create table table name select statement
Create a new table with query results
create table 表名 like 表2
Create a table with the structure of Table 2
9. Review:
Add column names
alter table add column new table column name the new data type
Modify the column name
alter table table name change column old column name for the new column names new data types;
Modify column data types
alter table modify column table column name the new data type
Remove Columns
alter table table name drop column column name
Modify the table name
Old alter table table name rename to new table name
10. Delete:
drop table if exists 表名
if exists, and only the table used to determine the library exists, and data can not use this column