The COMMENT ON statement (comment_on_statement) creates, alters, or drops a comment for a database object stored in the database catalog.
<comment_on_statement> ::= COMMENT ON <object_spec> IS <comment>
<object_spec> ::= see explanation
<comment> ::= <string_literal>
| <parameter_name>
Comments can be specified for the following database objects:
<object_spec> ::= |
Explanation |
COLUMN <table_name>.<column_name> |
The column must
exist in the specified table. The
current user must be the owner of the table. |
DBPROC[EDURE] <dbproc_name> |
dbproc_name must identify an existing database procedure whose owner is the current user. A comment is stored for the DB procedure. The comment can be interrogated by selecting the system table DOMAIN.DBPROCEDURES. |
DOMAIN <domain_name> |
domain_name must specify a domain of the current user. The comment for this domain can be interrogated by selecting the system table DOMAIN.DOMAINS. |
FOREIGN KEY <table_name>.<referential_constraint_name> |
referential_constraint_name must specify a referential CONSTRAINT
definition for the specified table. The current user must be the owner of the
table. |
INDEX <index_name> ON <table_name> |
index_name must specify an index of the specified
table. The current user must be
the owner of the table. |
SEQUENCE <sequence_name> |
An existing
sequence must be specified using sequence_name. The current user must be the owner of the
sequence. |
[PUBLIC] SYNONYM <synonym_name> |
synonym_name must specify a synonym of the current
user. |
TABLE <table_name> |
The specified
table must identify a base or view table of the current user that is not a
temporary table. The current user
must be the owner of the table. |
TRIGGER <trigger_name>.<table_name> |
The specified trigger name must identify a trigger of the specified table. The current user must be the owner of the table. A comment is stored for the trigger and can be interrogated by selecting the system table DOMAIN.TRIGGERS. |
USER <user_name> |
The specified user
must identify an existing user whose owner is the current user. |
USERGROUP <usergroup_name> |
The specified user
group must identify an existing user group whose owner is the current
user. |
The corresponding variable must contain one of the values listed in the table. The values must be encapsulated in quotation marks. Example of specifying the corresponding variables: 'COLUMN <table_name>.<column_name>' |