Oracle SQL: the Essential Reference

COMMENT

COMMENT ON {TABLE [schema.]{table | view | snapshot} | COLUMN [schema.]{table | view | snapshot}.column } IS 'text'

Adds a comment about a table, view, snapshot, or column into the data dictionary.

Keywords

schema

Specifies the name of a schema containing the table, view, or snapshot that will have a comment associated with it. If schema is omitted, the current schema is assumed.

TABLE

Specifies that the comment be associated with a table, view, or snapshot.

table

Specifies the name of a table with which the comment will be associated.

view

Specifies the name of a view with which the comment will be associated.

snapshot

Specifies the name of a snapshot with which the comment will be associated.

COLUMN

Specifies that the comment be associated with a column.

column

Specifies the name of the column to be commented.

text

The actual text of the comment. This text will be recorded in the data dictionary.

You can use the COMMENT ON COLUMN command to drop a comment. Simply set the comment to a null string (‘ ’).

Example

Add a comment to the ename column of scott's emp table:

COMMENT ON COLUMN scott.emp.ename IS 'Last name from personnel records';