AT clauses can be used in FOR loops only.

       An AT TOP clause specifies that when a group starts, the
       statement in the AT TOP clause has to be executed before
       executing the main code in the FOR loop. An AT BOTTOM clause
       specifies that an action has to be executed after the last record
       of a group has been processed and before the first record in the
       next group.

       Format

         AT BOTTOM OF  field-name [,...] statement

         AT TOP OF  field-name [,...] statement

1  –  Arguments

    field-name

       Is a field from the record definition for the loop's record
       stream.

    statement

       Is a DATATRIEVE statement.

2  –  Example

       In the following example the first AT BOTTOM clause is ignored
       because it is contained in an IF statement.

       DTR> DECLARE VAR PIC 9. ;
       DTR> READY CDD$TOP.DTR$LIB.DEMO.YACHTS ;
       DTR> VAR = 0 ;
       DTR> FOR FIRST 2 YACHTS
       CON>     BEGIN
       CON>     IF VAR EQ 0 THEN
       CON>            BEGIN
       CON>            AT BOTTOM OF MODEL PRINT "Model change";
       CON>            END ;
       CON>     AT BOTTOM OF BUILDER PRINT "Builder change";
       CON>     IF VAR GT 0 THEN
       CON>            BEGIN
       CON>            AT TOP OF MODEL PRINT "start model";
       CON>            END ;
       CON>     PRINT MODEL , BUILDER ;
       CON>     END ;

         MODEL    MANUFACTURER

       37 MK II    ALBERG
       Builder change
       79          ALBIN
       Builder change

       DTR>