PostgreSQL Logical Structure-view (v)

Defined

First, create a view

1. Syntax create [or replace] [temp |  Temporary] View name [(column_name [,...])] As query

2. Example: Create a view that can hide password:

postgres=# CREATE table users (ID int,user_name varchar (+), password varchar (n), user_email text,user_mark text); postgres=# CREATE View vw_users as select Id,user_name,user_email,user_mark from users; CREATE VIEW

　　

3, you can also use the temp or temporary keyword to create a view, when the session ends, the view disappears:

postgres=# Create temp View vw_users as select Id,user_name,user_email,user_mark from users; CREATE viewpostgres=# INSERT INTO  users values (1, ' A ', ' 123455 ', ' [email protected] '); Insert 0 1

\q exits and disappears after landing.

4. The view can also define another name for each column of the query. column names, such as the ID, user_name, user_email, User_mark, etc. in the original table, are redefined as no, name, email, Mark,

postgres=# CREATE View Vm_users (No,name,email,mark) as select id,user_name,postgres-# User_email,user_mark from users; CREATE viewpostgres=# SELECT * from Vm_users; No | name |    Email     | Mark----+------+--------------+------  1 | a    | [Email protected] | (1 row) postgres=#

　　

Second, can update the view

PostgreSQL Logical Structure-view (v)