MySQL basic operation (emphasis)

1. Display Database

   Show  

2. Enter the specified database

   Use database name

3. Create a database

   Create database name default character Set=utf8

4. Deleting a database

   Drop database name

Second, the operation of the database table

2. To create a table:

   Create Tabale studentinfo (name varchar (not null,sex char(ten) null,age int (5), Phone bigint (one)) Studentinfo The name of the table you created

4. Delete a table

   drop table name;

5. Add Table Data

    #   add one data at a time   Insert into Studentinfo (name,sex,age) VALUES (  "  Lai poetry   ", "   female  , "  12   ) 

    #   add more than one data at a time   Insert into Studentinfo (name,sex,age) VALUES (  "  Lai poetry   ", "   female  , "  21   "), ("   poetry   ", "   female  , "  22   " ) insert into table name (field name, multiple at, interval) values (specific values multiple at, interval)  

7. Modify

   ' Li Poetry ' ' Poems of Small poems '

9. Delete

    from table name where condition

Simple query of database tables (a simple small example)

2. Find all people

    from people

4. Only the person's name and age are queried

    from people

6. What are the people aged 20?

    from '  - '

8. What are the people who look for a 60-year-old?

    SELECT * from  people where P_age <  " Span style= "COLOR: #800000" >60   "  Find people ages 60 years old Select  * from  people where p_age <> "  60   "  (recommended, official) Select  * from  people where p_age! = Span style= "COLOR: #800000" > " 60  "  Span style= "COLOR: #000000" > (unconventional) common logical operators  <, =, <=, >=, <>,! = 

10. What are the people over the age of 50 who have a salary greater than 8000?

     from people where p_age > 50 | | P_sal < 8000#   Note: and is used to connect two conditional representations and meaning #or           to connect two conditional representations or meanings

12. Find the person surnamed Zhang

     from p_name like ' Zhang% ',
    
    SELECT * from Prople wherer p_name like '% sheet% '
    # There's a word in the middle #
    

13. Find out which people belong to the Wudang Huashan Songshan

    SELECT * fromPeople where P_menpai ='Wudang' orP_menpai ='Huashan' orP_menpai ='Songshan'; Select* fromPeople where P_menpaiinch('Wudang','Huashan','Songshan');#No: not in

15. What are the people who inquire about the salary at 5000-8900?

     from  and P_sal <= 8900 from and 8900;

17. Query all people, ask for a sort of reverse wage

     from people where p_sal > The ORDER by p_sal ask

19. Find the leader of a person aged 21 years

    # Select P_learder from people where p_age = ' + ' # SELECR * from people where p_id = ' p003 '  from'+')
    
    

MySQL basic operation (emphasis)