1ALTER DOMAIN(7) PostgreSQL 13.3 Documentation ALTER DOMAIN(7)
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6 ALTER_DOMAIN - change the definition of a domain
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9 ALTER DOMAIN name
10 { SET DEFAULT expression | DROP DEFAULT }
11 ALTER DOMAIN name
12 { SET | DROP } NOT NULL
13 ALTER DOMAIN name
14 ADD domain_constraint [ NOT VALID ]
15 ALTER DOMAIN name
16 DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ]
17 ALTER DOMAIN name
18 RENAME CONSTRAINT constraint_name TO new_constraint_name
19 ALTER DOMAIN name
20 VALIDATE CONSTRAINT constraint_name
21 ALTER DOMAIN name
22 OWNER TO { new_owner | CURRENT_USER | SESSION_USER }
23 ALTER DOMAIN name
24 RENAME TO new_name
25 ALTER DOMAIN name
26 SET SCHEMA new_schema
27
29 ALTER DOMAIN changes the definition of an existing domain. There are
30 several sub-forms:
31 SET/DROP DEFAULT
33 These forms set or remove the default value for a domain. Note that
34 defaults only apply to subsequent INSERT commands; they do not
35 affect rows already in a table using the domain.
36 SET/DROP NOT NULL
38 These forms change whether a domain is marked to allow NULL values
39 or to reject NULL values. You can only SET NOT NULL when the
40 columns using the domain contain no null values.
41 ADD domain_constraint [ NOT VALID ]
43 This form adds a new constraint to a domain using the same syntax
44 as CREATE DOMAIN (CREATE_DOMAIN(7)). When a new constraint is added
45 to a domain, all columns using that domain will be checked against
46 the newly added constraint. These checks can be suppressed by
47 adding the new constraint using the NOT VALID option; the
48 constraint can later be made valid using ALTER DOMAIN ... VALIDATE
49 CONSTRAINT. Newly inserted or updated rows are always checked
50 against all constraints, even those marked NOT VALID. NOT VALID is
51 only accepted for CHECK constraints.
52 DROP CONSTRAINT [ IF EXISTS ]
54 This form drops constraints on a domain. If IF EXISTS is specified
55 and the constraint does not exist, no error is thrown. In this case
56 a notice is issued instead.
57 RENAME CONSTRAINT
59 This form changes the name of a constraint on a domain.
60 VALIDATE CONSTRAINT
62 This form validates a constraint previously added as NOT VALID,
63 that is, it verifies that all values in table columns of the domain
64 type satisfy the specified constraint.
65 OWNER
67 This form changes the owner of the domain to the specified user.
68 RENAME
70 This form changes the name of the domain.
71 SET SCHEMA
73 This form changes the schema of the domain. Any constraints
74 associated with the domain are moved into the new schema as well.
75 You must own the domain to use ALTER DOMAIN. To change the schema of a
77 domain, you must also have CREATE privilege on the new schema. To alter
78 the owner, you must also be a direct or indirect member of the new
79 owning role, and that role must have CREATE privilege on the domain's
80 schema. (These restrictions enforce that altering the owner doesn't do
81 anything you couldn't do by dropping and recreating the domain.
82 However, a superuser can alter ownership of any domain anyway.)
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85 name
86 The name (possibly schema-qualified) of an existing domain to
87 alter.
88 domain_constraint
90 New domain constraint for the domain.
91 constraint_name
93 Name of an existing constraint to drop or rename.
94 NOT VALID
96 Do not verify existing stored data for constraint validity.
97 CASCADE
99 Automatically drop objects that depend on the constraint, and in
100 turn all objects that depend on those objects (see Section 5.14).
101 RESTRICT
103 Refuse to drop the constraint if there are any dependent objects.
104 This is the default behavior.
105 new_name
107 The new name for the domain.
108 new_constraint_name
110 The new name for the constraint.
111 new_owner
113 The user name of the new owner of the domain.
114 new_schema
116 The new schema for the domain.
117
119 Although ALTER DOMAIN ADD CONSTRAINT attempts to verify that existing
120 stored data satisfies the new constraint, this check is not
121 bulletproof, because the command cannot “see” table rows that are newly
122 inserted or updated and not yet committed. If there is a hazard that
123 concurrent operations might insert bad data, the way to proceed is to
124 add the constraint using the NOT VALID option, commit that command,
125 wait until all transactions started before that commit have finished,
126 and then issue ALTER DOMAIN VALIDATE CONSTRAINT to search for data
127 violating the constraint. This method is reliable because once the
128 constraint is committed, all new transactions are guaranteed to enforce
129 it against new values of the domain type.
130 Currently, ALTER DOMAIN ADD CONSTRAINT, ALTER DOMAIN VALIDATE
132 CONSTRAINT, and ALTER DOMAIN SET NOT NULL will fail if the named domain
133 or any derived domain is used within a container-type column (a
134 composite, array, or range column) in any table in the database. They
135 should eventually be improved to be able to verify the new constraint
136 for such nested values.
137
139 To add a NOT NULL constraint to a domain:
140 ALTER DOMAIN zipcode SET NOT NULL;
142 To remove a NOT NULL constraint from a domain:
144 ALTER DOMAIN zipcode DROP NOT NULL;
146 To add a check constraint to a domain:
148 ALTER DOMAIN zipcode ADD CONSTRAINT zipchk CHECK (char_length(VALUE) = 5);
150 To remove a check constraint from a domain:
152 ALTER DOMAIN zipcode DROP CONSTRAINT zipchk;
154 To rename a check constraint on a domain:
156 ALTER DOMAIN zipcode RENAME CONSTRAINT zipchk TO zip_check;
158 To move the domain into a different schema:
160 ALTER DOMAIN zipcode SET SCHEMA customers;
162
164 ALTER DOMAIN conforms to the SQL standard, except for the OWNER,
165 RENAME, SET SCHEMA, and VALIDATE CONSTRAINT variants, which are
166 PostgreSQL extensions. The NOT VALID clause of the ADD CONSTRAINT
167 variant is also a PostgreSQL extension.
168
170 CREATE DOMAIN (CREATE_DOMAIN(7)), DROP DOMAIN (DROP_DOMAIN(7))
171PostgreSQL 13.3 2021 ALTER DOMAIN(7)