create_view(7)

1CREATE VIEW()                    SQL Commands                    CREATE VIEW()
2
3
4

NAME

6       CREATE VIEW - define a new view
7
8

SYNOPSIS

10       CREATE [ OR REPLACE ] [ TEMP | TEMPORARY ] VIEW name [ ( column_name [, ...] ) ]
11           AS query
12
13

DESCRIPTION

15       CREATE VIEW defines a view of a query. The view is not physically mate‐
16       rialized. Instead, the query is run every time the view  is  referenced
17       in a query.
18
19       CREATE  OR  REPLACE  VIEW  is  similar,  but if a view of the same name
20       already exists, it is replaced. You can only replace a view with a  new
21       query  that  generates  the identical set of columns (i.e., same column
22       names and data types).
23
24       If a schema name is given (for  example,  CREATE  VIEW  myschema.myview
25       ...)  then the view is created in the specified schema. Otherwise it is
26       created in the current schema.  Temporary  views  exist  in  a  special
27       schema,  so  a  schema  name may not be given when creating a temporary
28       view. The name of the view must be distinct from the name of any  other
29       view, table, sequence, or index in the same schema.
30

PARAMETERS

32       TEMPORARY or TEMP
33              If  specified,  the view is created as a temporary view.  Tempo‐
34              rary views are automatically dropped at the end of  the  current
35              session. Existing permanent relations with the same name are not
36              visible to the current session while the temporary view  exists,
37              unless they are referenced with schema-qualified names.
38
39              If  any  of the tables referenced by the view are temporary, the
40              view is created as a temporary view (whether TEMPORARY is speci‐
41              fied or not).
42
43       name   The name (optionally schema-qualified) of a view to be created.
44
45       column_name
46              An  optional  list  of names to be used for columns of the view.
47              If not given, the column names are deduced from the query.
48
49       query  A SELECT [select(7)] or VALUES [values(7)]  command  which  will
50              provide the columns and rows of the view.
51

NOTES

53       Currently,  views  are  read only: the system will not allow an insert,
54       update, or delete on a view. You can get the  effect  of  an  updatable
55       view  by  creating  rules  that  rewrite inserts, etc. on the view into
56       appropriate actions on other tables. For more  information  see  CREATE
57       RULE [create_rule(7)].
58
59       Use the DROP VIEW [drop_view(7)] statement to drop views.
60
61       Be  careful  that  the  names  and  types of the view's columns will be
62       assigned the way you want. For example,
63
64       CREATE VIEW vista AS SELECT 'Hello World';
65
66       is bad form in two ways: the column name defaults to ?column?, and  the
67       column data type defaults to unknown. If you want a string literal in a
68       view's result, use something like
69
70       CREATE VIEW vista AS SELECT text 'Hello World' AS hello;
71
72
73       Access to tables referenced in the view is determined by permissions of
74       the  view  owner. However, functions called in the view are treated the
75       same as if they had been called directly from the query using the view.
76       Therefore  the  user  of a view must have permissions to call all func‐
77       tions used by the view.
78

EXAMPLES

80       Create a view consisting of all comedy films:
81
82       CREATE VIEW comedies AS
83           SELECT *
84           FROM films
85           WHERE kind = 'Comedy';
86
87

COMPATIBILITY

89       The SQL standard specifies some additional capabilities for the  CREATE
90       VIEW statement:
91
92       CREATE VIEW name [ ( column_name [, ...] ) ]
93           AS query
94           [ WITH [ CASCADED | LOCAL ] CHECK OPTION ]
95
96
97       The optional clauses for the full SQL command are:
98
99       CHECK OPTION
100              This  option  has  to  do  with  updatable views. All INSERT and
101              UPDATE commands on the view will be checked to ensure data  sat‐
102              isfy the view-defining condition (that is, the new data would be
103              visible through the view). If they do not, the  update  will  be
104              rejected.
105
106       LOCAL  Check for integrity on this view.
107
108       CASCADED
109              Check for integrity on this view and on any dependent view. CAS‐
110              CADED is assumed if neither CASCADED nor LOCAL is specified.
111
112       CREATE OR REPLACE VIEW is a PostgreSQL language extension.  So  is  the
113       concept of a temporary view.
114