SQL Reference

update-clause

>>-FOR UPDATE----+-------------------------+-------------------><
                 |     .-,--------------.  |
                 |     V                |  |
                 '-OF-----column-name---+--'
 

The FOR UPDATE clause identifies the columns that can be updated in a subsequent Positioned UPDATE statement. Each column-name must be unqualified and must identify a column of the table or view identified in the first FROM clause of the fullselect. If the FOR UPDATE clause is specified without column names, all updatable columns of the table or view identified in the first FROM clause of the fullselect are included.

The FOR UPDATE clause cannot be used if one of the following is true:

• The cursor associated with the select-statement is not deletable (see Notes).
• One of the selected columns is a non-updatable column of a catalog table and the FOR UPDATE clause has not been used to exclude that column.