1ALTER TYPE(7) PostgreSQL 12.6 Documentation ALTER TYPE(7)
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6 ALTER_TYPE - change the definition of a type
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9 ALTER TYPE name action [, ... ]
10 ALTER TYPE name OWNER TO { new_owner | CURRENT_USER | SESSION_USER }
11 ALTER TYPE name RENAME ATTRIBUTE attribute_name TO new_attribute_name [ CASCADE | RESTRICT ]
12 ALTER TYPE name RENAME TO new_name
13 ALTER TYPE name SET SCHEMA new_schema
14 ALTER TYPE name ADD VALUE [ IF NOT EXISTS ] new_enum_value [ { BEFORE | AFTER } neighbor_enum_value ]
15 ALTER TYPE name RENAME VALUE existing_enum_value TO new_enum_value
16 where action is one of:
18 ADD ATTRIBUTE attribute_name data_type [ COLLATE collation ] [ CASCADE | RESTRICT ]
20 DROP ATTRIBUTE [ IF EXISTS ] attribute_name [ CASCADE | RESTRICT ]
21 ALTER ATTRIBUTE attribute_name [ SET DATA ] TYPE data_type [ COLLATE collation ] [ CASCADE | RESTRICT ]
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24 ALTER TYPE changes the definition of an existing type. There are
25 several subforms:
26 ADD ATTRIBUTE
28 This form adds a new attribute to a composite type, using the same
29 syntax as CREATE TYPE (CREATE_TYPE(7)).
30 DROP ATTRIBUTE [ IF EXISTS ]
32 This form drops an attribute from a composite type. If IF EXISTS is
33 specified and the attribute does not exist, no error is thrown. In
34 this case a notice is issued instead.
35 SET DATA TYPE
37 This form changes the type of an attribute of a composite type.
38 OWNER
40 This form changes the owner of the type.
41 RENAME
43 This form changes the name of the type or the name of an individual
44 attribute of a composite type.
45 SET SCHEMA
47 This form moves the type into another schema.
48 ADD VALUE [ IF NOT EXISTS ] [ BEFORE | AFTER ]
50 This form adds a new value to an enum type. The new value's place
51 in the enum's ordering can be specified as being BEFORE or AFTER
52 one of the existing values. Otherwise, the new item is added at the
53 end of the list of values.
54 If IF NOT EXISTS is specified, it is not an error if the type
56 already contains the new value: a notice is issued but no other
57 action is taken. Otherwise, an error will occur if the new value is
58 already present.
59 RENAME VALUE
61 This form renames a value of an enum type. The value's place in the
62 enum's ordering is not affected. An error will occur if the
63 specified value is not present or the new name is already present.
64 The ADD ATTRIBUTE, DROP ATTRIBUTE, and ALTER ATTRIBUTE actions can be
66 combined into a list of multiple alterations to apply in parallel. For
67 example, it is possible to add several attributes and/or alter the type
68 of several attributes in a single command.
69 You must own the type to use ALTER TYPE. To change the schema of a
71 type, you must also have CREATE privilege on the new schema. To alter
72 the owner, you must also be a direct or indirect member of the new
73 owning role, and that role must have CREATE privilege on the type's
74 schema. (These restrictions enforce that altering the owner doesn't do
75 anything you couldn't do by dropping and recreating the type. However,
76 a superuser can alter ownership of any type anyway.) To add an
77 attribute or alter an attribute type, you must also have USAGE
78 privilege on the data type.
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81 name
82 The name (possibly schema-qualified) of an existing type to alter.
83 new_name
85 The new name for the type.
86 new_owner
88 The user name of the new owner of the type.
89 new_schema
91 The new schema for the type.
92 attribute_name
94 The name of the attribute to add, alter, or drop.
95 new_attribute_name
97 The new name of the attribute to be renamed.
98 data_type
100 The data type of the attribute to add, or the new type of the
101 attribute to alter.
102 new_enum_value
104 The new value to be added to an enum type's list of values, or the
105 new name to be given to an existing value. Like all enum literals,
106 it needs to be quoted.
107 neighbor_enum_value
109 The existing enum value that the new value should be added
110 immediately before or after in the enum type's sort ordering. Like
111 all enum literals, it needs to be quoted.
112 existing_enum_value
114 The existing enum value that should be renamed. Like all enum
115 literals, it needs to be quoted.
116 CASCADE
118 Automatically propagate the operation to typed tables of the type
119 being altered, and their descendants.
120 RESTRICT
122 Refuse the operation if the type being altered is the type of a
123 typed table. This is the default.
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126 If ALTER TYPE ... ADD VALUE (the form that adds a new value to an enum
127 type) is executed inside a transaction block, the new value cannot be
128 used until after the transaction has been committed.
129 Comparisons involving an added enum value will sometimes be slower than
131 comparisons involving only original members of the enum type. This will
132 usually only occur if BEFORE or AFTER is used to set the new value's
133 sort position somewhere other than at the end of the list. However,
134 sometimes it will happen even though the new value is added at the end
135 (this occurs if the OID counter “wrapped around” since the original
136 creation of the enum type). The slowdown is usually insignificant; but
137 if it matters, optimal performance can be regained by dropping and
138 recreating the enum type, or by dumping and reloading the database.
139
141 To rename a data type:
142 ALTER TYPE electronic_mail RENAME TO email;
144 To change the owner of the type email to joe:
146 ALTER TYPE email OWNER TO joe;
148 To change the schema of the type email to customers:
150 ALTER TYPE email SET SCHEMA customers;
152 To add a new attribute to a type:
154 ALTER TYPE compfoo ADD ATTRIBUTE f3 int;
156 To add a new value to an enum type in a particular sort position:
158 ALTER TYPE colors ADD VALUE 'orange' AFTER 'red';
160 To rename an enum value:
162 ALTER TYPE colors RENAME VALUE 'purple' TO 'mauve';
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166 The variants to add and drop attributes are part of the SQL standard;
167 the other variants are PostgreSQL extensions.
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170 CREATE TYPE (CREATE_TYPE(7)), DROP TYPE (DROP_TYPE(7))
171PostgreSQL 12.6 2021 ALTER TYPE(7)