The DOUBLE_PRECISION and DOUBLE functions return a double-precision floating-point representation of either a number or a string representation of a number.
The schema is SYSIBM.
The result is the same number that would occur if the argument were assigned to a double-precision floating-point column or variable. If the numeric value of the argument is not within the range of double-precision floating-point, an error is returned (SQLSTATE 22003).
The result is the same number that would result from CAST(string-expression AS DOUBLE PRECISION). Leading and trailing blanks are eliminated and the resulting string must conform to the rules for forming a valid numeric constant (SQLSTATE 22018). If the numeric value of the argument is not within the range of double-precision floating-point, an error is returned (SQLSTATE 22003).
The result of the function is a double-precision floating-point number. If the argument can be null, the result can be null; if the argument is null, the result is the null value.
SELECT EMPNO, DOUBLE(SALARY)/COMM
FROM EMPLOYEE
WHERE COMM > 0