1COMMENT(7) PostgreSQL 15.4 Documentation COMMENT(7)
2
6 COMMENT - define or change the comment of an object
7
9 COMMENT ON
10 {
11 ACCESS METHOD object_name |
12 AGGREGATE aggregate_name ( aggregate_signature ) |
13 CAST (source_type AS target_type) |
14 COLLATION object_name |
15 COLUMN relation_name.column_name |
16 CONSTRAINT constraint_name ON table_name |
17 CONSTRAINT constraint_name ON DOMAIN domain_name |
18 CONVERSION object_name |
19 DATABASE object_name |
20 DOMAIN object_name |
21 EXTENSION object_name |
22 EVENT TRIGGER object_name |
23 FOREIGN DATA WRAPPER object_name |
24 FOREIGN TABLE object_name |
25 FUNCTION function_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
26 INDEX object_name |
27 LARGE OBJECT large_object_oid |
28 MATERIALIZED VIEW object_name |
29 OPERATOR operator_name (left_type, right_type) |
30 OPERATOR CLASS object_name USING index_method |
31 OPERATOR FAMILY object_name USING index_method |
32 POLICY policy_name ON table_name |
33 [ PROCEDURAL ] LANGUAGE object_name |
34 PROCEDURE procedure_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
35 PUBLICATION object_name |
36 ROLE object_name |
37 ROUTINE routine_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
38 RULE rule_name ON table_name |
39 SCHEMA object_name |
40 SEQUENCE object_name |
41 SERVER object_name |
42 STATISTICS object_name |
43 SUBSCRIPTION object_name |
44 TABLE object_name |
45 TABLESPACE object_name |
46 TEXT SEARCH CONFIGURATION object_name |
47 TEXT SEARCH DICTIONARY object_name |
48 TEXT SEARCH PARSER object_name |
49 TEXT SEARCH TEMPLATE object_name |
50 TRANSFORM FOR type_name LANGUAGE lang_name |
51 TRIGGER trigger_name ON table_name |
52 TYPE object_name |
53 VIEW object_name
54 } IS { string_literal | NULL }
55 where aggregate_signature is:
57 * |
59 [ argmode ] [ argname ] argtype [ , ... ] |
60 [ [ argmode ] [ argname ] argtype [ , ... ] ] ORDER BY [ argmode ] [ argname ] argtype [ , ... ]
61
63 COMMENT stores a comment about a database object.
64 Only one comment string is stored for each object, so to modify a
66 comment, issue a new COMMENT command for the same object. To remove a
67 comment, write NULL in place of the text string. Comments are
68 automatically dropped when their object is dropped.
69 A SHARE UPDATE EXCLUSIVE lock is acquired on the object to be
71 commented.
72 For most kinds of object, only the object's owner can set the comment.
74 Roles don't have owners, so the rule for COMMENT ON ROLE is that you
75 must be superuser to comment on a superuser role, or have the
76 CREATEROLE privilege to comment on non-superuser roles. Likewise,
77 access methods don't have owners either; you must be superuser to
78 comment on an access method. Of course, a superuser can comment on
79 anything.
80 Comments can be viewed using psql's \d family of commands. Other user
82 interfaces to retrieve comments can be built atop the same built-in
83 functions that psql uses, namely obj_description, col_description, and
84 shobj_description (see Table 9.77).
85
87 object_name
88 relation_name.column_name
89 aggregate_name
90 constraint_name
91 function_name
92 operator_name
93 policy_name
94 procedure_name
95 routine_name
96 rule_name
97 trigger_name
98 The name of the object to be commented. Names of objects that
99 reside in schemas (tables, functions, etc.) can be
100 schema-qualified. When commenting on a column, relation_name must
101 refer to a table, view, composite type, or foreign table.
102 table_name
104 domain_name
105 When creating a comment on a constraint, a trigger, a rule or a
106 policy these parameters specify the name of the table or domain on
107 which that object is defined.
108 source_type
110 The name of the source data type of the cast.
111 target_type
113 The name of the target data type of the cast.
114 argmode
116 The mode of a function, procedure, or aggregate argument: IN, OUT,
117 INOUT, or VARIADIC. If omitted, the default is IN. Note that
118 COMMENT does not actually pay any attention to OUT arguments, since
119 only the input arguments are needed to determine the function's
120 identity. So it is sufficient to list the IN, INOUT, and VARIADIC
121 arguments.
122 argname
124 The name of a function, procedure, or aggregate argument. Note that
125 COMMENT does not actually pay any attention to argument names,
126 since only the argument data types are needed to determine the
127 function's identity.
128 argtype
130 The data type of a function, procedure, or aggregate argument.
131 large_object_oid
133 The OID of the large object.
134 left_type
136 right_type
137 The data type(s) of the operator's arguments (optionally
138 schema-qualified). Write NONE for the missing argument of a prefix
139 operator.
140 PROCEDURAL
142 This is a noise word.
143 type_name
145 The name of the data type of the transform.
146 lang_name
148 The name of the language of the transform.
149 string_literal
151 The new comment contents, written as a string literal.
152 NULL
154 Write NULL to drop the comment.
155
157 There is presently no security mechanism for viewing comments: any user
158 connected to a database can see all the comments for objects in that
159 database. For shared objects such as databases, roles, and tablespaces,
160 comments are stored globally so any user connected to any database in
161 the cluster can see all the comments for shared objects. Therefore,
162 don't put security-critical information in comments.
163
165 Attach a comment to the table mytable:
166 COMMENT ON TABLE mytable IS 'This is my table.';
168 Remove it again:
170 COMMENT ON TABLE mytable IS NULL;
172 Some more examples:
174 COMMENT ON ACCESS METHOD gin IS 'GIN index access method';
176 COMMENT ON AGGREGATE my_aggregate (double precision) IS 'Computes sample variance';
177 COMMENT ON CAST (text AS int4) IS 'Allow casts from text to int4';
178 COMMENT ON COLLATION "fr_CA" IS 'Canadian French';
179 COMMENT ON COLUMN my_table.my_column IS 'Employee ID number';
180 COMMENT ON CONVERSION my_conv IS 'Conversion to UTF8';
181 COMMENT ON CONSTRAINT bar_col_cons ON bar IS 'Constrains column col';
182 COMMENT ON CONSTRAINT dom_col_constr ON DOMAIN dom IS 'Constrains col of domain';
183 COMMENT ON DATABASE my_database IS 'Development Database';
184 COMMENT ON DOMAIN my_domain IS 'Email Address Domain';
185 COMMENT ON EVENT TRIGGER abort_ddl IS 'Aborts all DDL commands';
186 COMMENT ON EXTENSION hstore IS 'implements the hstore data type';
187 COMMENT ON FOREIGN DATA WRAPPER mywrapper IS 'my foreign data wrapper';
188 COMMENT ON FOREIGN TABLE my_foreign_table IS 'Employee Information in other database';
189 COMMENT ON FUNCTION my_function (timestamp) IS 'Returns Roman Numeral';
190 COMMENT ON INDEX my_index IS 'Enforces uniqueness on employee ID';
191 COMMENT ON LANGUAGE plpython IS 'Python support for stored procedures';
192 COMMENT ON LARGE OBJECT 346344 IS 'Planning document';
193 COMMENT ON MATERIALIZED VIEW my_matview IS 'Summary of order history';
194 COMMENT ON OPERATOR ^ (text, text) IS 'Performs intersection of two texts';
195 COMMENT ON OPERATOR - (NONE, integer) IS 'Unary minus';
196 COMMENT ON OPERATOR CLASS int4ops USING btree IS '4 byte integer operators for btrees';
197 COMMENT ON OPERATOR FAMILY integer_ops USING btree IS 'all integer operators for btrees';
198 COMMENT ON POLICY my_policy ON mytable IS 'Filter rows by users';
199 COMMENT ON PROCEDURE my_proc (integer, integer) IS 'Runs a report';
200 COMMENT ON PUBLICATION alltables IS 'Publishes all operations on all tables';
201 COMMENT ON ROLE my_role IS 'Administration group for finance tables';
202 COMMENT ON ROUTINE my_routine (integer, integer) IS 'Runs a routine (which is a function or procedure)';
203 COMMENT ON RULE my_rule ON my_table IS 'Logs updates of employee records';
204 COMMENT ON SCHEMA my_schema IS 'Departmental data';
205 COMMENT ON SEQUENCE my_sequence IS 'Used to generate primary keys';
206 COMMENT ON SERVER myserver IS 'my foreign server';
207 COMMENT ON STATISTICS my_statistics IS 'Improves planner row estimations';
208 COMMENT ON SUBSCRIPTION alltables IS 'Subscription for all operations on all tables';
209 COMMENT ON TABLE my_schema.my_table IS 'Employee Information';
210 COMMENT ON TABLESPACE my_tablespace IS 'Tablespace for indexes';
211 COMMENT ON TEXT SEARCH CONFIGURATION my_config IS 'Special word filtering';
212 COMMENT ON TEXT SEARCH DICTIONARY swedish IS 'Snowball stemmer for Swedish language';
213 COMMENT ON TEXT SEARCH PARSER my_parser IS 'Splits text into words';
214 COMMENT ON TEXT SEARCH TEMPLATE snowball IS 'Snowball stemmer';
215 COMMENT ON TRANSFORM FOR hstore LANGUAGE plpython3u IS 'Transform between hstore and Python dict';
216 COMMENT ON TRIGGER my_trigger ON my_table IS 'Used for RI';
217 COMMENT ON TYPE complex IS 'Complex number data type';
218 COMMENT ON VIEW my_view IS 'View of departmental costs';
219
221 There is no COMMENT command in the SQL standard.
222PostgreSQL 15.4 2023 COMMENT(7)