DOUBLE_PRECISION or DOUBLE or FLOAT

Returns a floating-point representation of a number or a decimal, integer, or floating-point number represented by a character string. The argument must be a number.

Example:

Using the EMPLOYEE table, find the ratio of salary to commission for employees whose commission is not zero. The columns involved (SALARY and COMM) have DECIMAL data types. To eliminate the possibility of out-of-range results, DOUBLE_PRECISION is applied to SALARY so that the division is carried out in floating point:

  SELECT EMPNO, DOUBLE_PRECISION(SALARY)/COMM
    FROM EMPLOYEE
    WHERE COMM > 0