Detailed steps for MySQL to create a view
Let's talk about the detailed steps of creating views in MySQL. The secret of the text is that it is relevant to the topic. So, instead of gossiping, let's go straight to the following, and I'm sure you'll benefit from reading this article on the detailed steps for creating views in MySQL.
1. View Overview: a view is a table derived from one or more tables, it is a virtual table, and the structure and data of the table depend on the base table
two。 Syntax format for creating views: view creation is based on SELECT statements
CREATE [OR REPLACE] [ALGORITHM] = {UNDEFINDE | MERGE | TEMPTABLE}]
VIEW view_name [(column_list)]
AS SELECT_statement
[WITH [CASCADED | LOCAL] CHECK OPTION]
/ / OR REPLACE indicates that the statement can replace the existing view
/ / ALGORITHM represents the algorithm for view selection
/ / UNDEFINDE represents MySQL automatic selection algorithm
/ / MERGE: merge the statement that uses the view with the view definition, and some part of the view definition replaces the corresponding part of the statement
/ / TEMPTABEL: view is stored in temporary table
/ / column_list: property list, which specifies the names of each property in the view
/ / AS: actions to be performed by the view
/ / CASCADED: cascading to meet the conditions of all related views and tables related to this view
/ / LOCAL: optional, as long as the definition of the view is satisfied
two。 Create a view on a single table
Create view play_v as select id,name from star
Select * from play_v
Create view play_v1 (number,player) as select id,name from star
3. Create a view on multiple tables
Create view pallet (number,player,team)
As
Select star.id,star.name,team.name from star,team where star.team_id = team.id
Select * from Putt
4. View view
DESCRIBE view name / / or DESC view name
Desc play_v1
SHOW TABLE STATUS LIKE 'View name'
Show table status like'poundt'
SHOW CREATE VIEW View name
Show create view play_v
5. Modify the view: when some fields in the basic table change
(1) use CREATE OR REPLACE VIEW statement to modify the view
Create or replace view play_v as select * from student
(2)
ALTER [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}]
VIEW view_name [(column_list)]
AS SELECT_statement
[WITH [CASCADED | LOCAL] CHECK OPTION]
~ use alter to modify the view structure
Alter view play_v1 as select team_id,name from star
6. Update View
(1) UPDATE statement
Update view pairt set number = null
(2) INSERT statement
Insert into star values (11 Clay-Thompson, 4); the # view also changes.
(3) DELETE statement
The data deleted in the delete from view 11; # is the data in the basic table.
7. Delete View
DROP VIEW [IF EXISTS] view_name [, view_name.] [RESTRICT | CASCADE]
Drop view play_v1
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