Numeric to Double
>>-+-DOUBLE_PRECISION-+--(--numeric-expression--)-------------->< '-DOUBLE-----------'
String to Double
>>-+-DOUBLE_PRECISION-+--(--string-expression--)--------------->< '-DOUBLE-----------'
The DOUBLE_PRECISION and DOUBLE functions return a floating-point representation of:
Numeric to Double
The result is the same number that would occur if the expression were assigned to a double-precision floating-point column or variable.
String to Double
If the argument is a string-expression, 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 floating-point, integer, or decimal constant.
The single-byte character constant that must be used to delimit the decimal digits in string-expression from the whole part of the number is the default decimal point. For more information, see Decimal point.
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.
Syntax alternatives: FLOAT is a synonym for DOUBLE_PRECISION and DOUBLE.
The CAST specification should be used for maximal portability. For more information, see CAST specification.
SELECT EMPNO, DOUBLE_PRECISION(SALARY)/COMM FROM EMPLOYEE WHERE COMM > 0
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