Provided by: postgresql-client-8.0_8.0.7-2build1_i386 bug

NAME

       COMMENT - define or change the comment of an object

SYNOPSIS

       COMMENT ON
       {
         TABLE object_name |
         COLUMN table_name.column_name |
         AGGREGATE agg_name (agg_type) |
         CAST (sourcetype AS targettype) |
         CONSTRAINT constraint_name ON table_name |
         CONVERSION object_name |
         DATABASE object_name |
         DOMAIN object_name |
         FUNCTION func_name (arg1_type, arg2_type, ...) |
         INDEX object_name |
         LARGE OBJECT large_object_oid |
         OPERATOR op (leftoperand_type, rightoperand_type) |
         OPERATOR CLASS object_name USING index_method |
         [ PROCEDURAL ] LANGUAGE object_name |
         RULE rule_name ON table_name |
         SCHEMA object_name |
         SEQUENCE object_name |
         TRIGGER trigger_name ON table_name |
         TYPE object_name |
         VIEW object_name
       } IS ’text’

DESCRIPTION

       COMMENT stores a comment about a database object.

       To  modify  a comment, issue a new COMMENT command for the same object.
       Only one comment string  is  stored  for  each  object.   To  remove  a
       comment,  write  NULL  in  place  of  the  text  string.   Comments are
       automatically dropped when the object is dropped.

       Comments can be easily retrieved with the psql commands \dd,  \d+,  and
       \l+.   Other user interfaces to retrieve comments can be built atop the
       same built-in functions that  psql  uses,  namely  obj_description  and
       col_description (see the documentation).

PARAMETERS

       object_name

       table_name.column_name

       agg_name

       constraint_name

       func_name

       op

       rule_name

       trigger_name
              The  name  of  the  object  to  be  commented.  Names of tables,
              aggregates, domains,  functions,  indexes,  operators,  operator
              classes, sequences, types, and views may be schema-qualified.

       agg_type
              The  argument  data  type of the aggregate function, or * if the
              function accepts any data type.

       large_object_oid
              The OID of the large object.

       PROCEDURAL
              This is a noise word.

       sourcetype
              The name of the source data type of the cast.

       targettype
              The name of the target data type of the cast.

       text   The new comment, written as a string literal; or  NULL  to  drop
              the comment.

NOTES

       A comment for a database can only be created in that database, and will
       only be visible in that database, not in other databases.

       There is  presently  no  security  mechanism  for  comments:  any  user
       connected  to  a  database can see all the comments for objects in that
       database (although only superusers can change comments for objects that
       they  don’t own). Therefore, don’t put security-critical information in
       comments.

EXAMPLES

       Attach a comment to the table mytable:

       COMMENT ON TABLE mytable IS ’This is my table.’;

       Remove it again:

       COMMENT ON TABLE mytable IS NULL;

       Some more examples:

       COMMENT ON AGGREGATE my_aggregate (double precision) IS ’Computes sample variance’;
       COMMENT ON CAST (text AS int4) IS ’Allow casts from text to int4’;
       COMMENT ON COLUMN my_table.my_column IS ’Employee ID number’;
       COMMENT ON CONVERSION my_conv IS ’Conversion to Unicode’;
       COMMENT ON DATABASE my_database IS ’Development Database’;
       COMMENT ON DOMAIN my_domain IS ’Email Address Domain’;
       COMMENT ON FUNCTION my_function (timestamp) IS ’Returns Roman Numeral’;
       COMMENT ON INDEX my_index IS ’Enforces uniqueness on employee ID’;
       COMMENT ON LANGUAGE plpython IS ’Python support for stored procedures’;
       COMMENT ON LARGE OBJECT 346344 IS ’Planning document’;
       COMMENT ON OPERATOR ^ (text, text) IS ’Performs intersection of two texts’;
       COMMENT ON OPERATOR ^ (NONE, text) IS ’This is a prefix operator on text’;
       COMMENT ON OPERATOR CLASS int4ops USING btree IS ’4 byte integer operators for btrees’;
       COMMENT ON RULE my_rule ON my_table IS ’Logs updates of employee records’;
       COMMENT ON SCHEMA my_schema IS ’Departmental data’;
       COMMENT ON SEQUENCE my_sequence IS ’Used to generate primary keys’;
       COMMENT ON TABLE my_schema.my_table IS ’Employee Information’;
       COMMENT ON TRIGGER my_trigger ON my_table IS ’Used for RI’;
       COMMENT ON TYPE complex IS ’Complex number data type’;
       COMMENT ON VIEW my_view IS ’View of departmental costs’;

COMPATIBILITY

       There is no COMMENT command in the SQL standard.