The FIRST clause specifies the maximum number of records in a
    record stream formed by a record selection expression.

1  –  Examples

    The following programs demonstrate the use of the FIRST clause
    and the SORT clause. These programs sort the employees relation
    in ascending order based on EMPLOYEE_ID. The FIRST 50 statement
    creates a record stream that contains the first 50 records from
    the sorted employees relation. These programs print the employee
    ID and last name of these fifty employee records.

1.1  –  C Example

    #include <stdio.h>
    DATABASE PERS = FILENAME "PERSONNEL";

    main ( )
    {
    READY PERS;
    START_TRANSACTION READ_ONLY;

    FOR FIRST 50 E IN EMPLOYEES
       SORTED BY E.EMPLOYEE_ID
          printf ("%s  ",E.EMPLOYEE_ID);
          printf ("%s\n",E.LAST_NAME);
    END_FOR;

    COMMIT;
    FINISH;
    }

1.2  –  Pascal Example

    program first_clause (input,output);
    DATABASE PERS = FILENAME 'PERSONNEL';

    begin
    READY PERS;
    START_TRANSACTION READ_ONLY;

    FOR FIRST 50 E IN EMPLOYEES
       SORTED BY E.EMPLOYEE_ID
          writeln (E.EMPLOYEE_ID, ' ', E.LAST_NAME);
    END_FOR;

    COMMIT;
    FINISH;
    end.

2  –  Format

  (B)0first-clause =

    qqqqqq> FIRST qqqq> value-expr qqqq>

2.1  –  Format arguments

    value-expr             A value expression. A symbol or a string
                           of symbols used to calculate a value. When
                           you use a value expression in a statement,
                           Oracle Rdb calculates the value associated
                           with the expression and uses that value
                           when executing the statement.