Adding and retrieving comments

After you create an object, you can provide explanatory information about it for future reference. For example, you can provide information about the purpose of the object, who uses it, and anything unusual about it.

Begin general-use programming interface information.

You can create comments about tables, views, indexes, aliases, packages, plans, distinct types, triggers, stored procedures, and user-defined functions. You can store a comment about the table or the view as a whole, and you can also include a comment for each column. A comment must not exceed 762 bytes.

A comment is especially useful if your names do not clearly indicate the contents of columns or tables. In that case, use a comment to describe the specific contents of the column or table.

Below are two examples of COMMENT:

COMMENT ON TABLE DSN8C10.EMP IS
  'Employee table. Each row in this table represents one
   employee of the company.';

COMMENT ON COLUMN DSN8C10.PROJ.PRSTDATE IS
  'Estimated project start date. The format is DATE.';

After you execute a COMMENT statement, your comments are stored in the REMARKS column of SYSIBM.SYSTABLES or SYSIBM.SYSCOLUMNS. (Any comment that is already present in the row is replaced by the new one.) The next two examples retrieve the comments that are added by the previous COMMENT statements.

SELECT REMARKS
  FROM SYSIBM.SYSTABLES
  WHERE NAME = 'EMP'
  AND CREATOR = 'DSN8C10';

SELECT REMARKS
  FROM SYSIBM.SYSCOLUMNS
  WHERE NAME = 'PRSTDATE' AND TBNAME = 'PROJ'
  AND TBCREATOR = 'DSN8C10';

End general-use programming interface information.