Shulou(Shulou.com)06/01 Report--

Records in the MYSQL operation data table

1 put the number of selected columns to the top

ALTER TABCE table name MODIFY column name and type FIRST of column name

2 modify column name type

ALTERTABCE table name MODIFY column name new column name

3 modify the name of the data table

The first ALTERTABCE original table name RENAME new table name

The second RENAMETABLE new table name TO original table name

4 insert record

The first INSERT table name needs to be copied with the column VALUES (the value to be copied);] the name needs to be''. This is the use of copying only one field.

The second INSERT table name is VALUES (NULL or DEFAULT, such as' name', 'password', 'age', serial number)

The third INSERT table name SET user name = name, user password = password; (only one entry can be inserted)

5 View record

SELECT * FROM table name

6 insert multiple records

The first INSERT table name VALUES (NULL or DEFAULT, such as' name', 'password', 'age', serial number), (NULL, such as' name', 'password', 'age', serial number)

The second INSERT table name is SET user name = 'name' and password = 'password you want to fill in'

7 single table update

7.1 Update a field

UPDATE table name set age = age + the number you want to add; (add the value you fill in to your original value)

7.2 Update multiple fields

UPDATE table name SET age = age-e. G. id, e. G. sex=0; (subtract or set on your original value)

7.3 add updates to the conditions

UPDATE table name SET age = age + 10 WHERE such as id%2=0; (add the value you filled in to your original value, such as if id is even, you can update it)

8 single table delete record

DELETE FROM table name WHERE such as id=6; (delete information with id 6) and then insert id after deletion will only rank back, not the number of deletions.

9 query the columns you want to check

SELECT column name, column name FROM

10 aliases for query columns

SELECT such as id AS userId,username AS uname FROM table name

11 query result grouping

SELECT column name FROM table name GROUP BY column name

12 grouping condition

SELECT column name FROM table name GROUP BY 1 HAVING cound (id) > = 2; (the id of the list name is greater than or equal to 2 when grouped)

13 sort the query results

The first SELECT * FROM table name ORDER BY column name DESC; (descending)

The second SELECT * FROM table name ORDER BY column name; (ascending order)

The third SELECT * FROM table name ORDER BY column name, such as id DESC; (id descending sort of column names)

14 restrict query results

SELECT * FROM table name LIMIT 2; (query the first two pieces of information in the list)

15 put the query results in the specified list

INSERT new list name column name (such as username) SELECT column name (as before) FROM original table name WHERE column name (such as age) > = 30; (put values with username and ag greater than or equal to 30 in the specified list)

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.