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COMMENT(5)
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) |
    CONSTRAINT constraint_name ON table_name |
    DATABASE object_name |
    DOMAIN object_name |
    FUNCTION func_name (arg1_type, arg2_type, ...) |
    INDEX object_name |
    OPERATOR op (leftoperand_type, rightoperand_type) |
    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.  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.

  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.

PARAMETERS
  object_name

  table_name.column_name

  aggname

  constraint_name

  func_name

  op

  rule_name

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

  text The new comment.

NOTES
  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 COLUMN my_table.my_column IS 'Employee ID number';
  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 OPERATOR ^ (text, text) IS 'Performs intersection of two texts';
  COMMENT ON OPERATOR ^ (NONE, text) IS 'This is a prefix operator on text';
  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.

Index for Section 5

Alphabetical listing for C

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