The DOUBLE function returns a floating-point number corresponding
to a:
- number if the argument is a numeric expression.
- character string representation of a number if the argument is a string
expression.
Numeric to double
DOUBLE [PRECISION] (NumericExpression )
- NumericExpression
- The argument is an expression that returns a value of any built-in numeric
data type.
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. The result is the same number that
would occur if the argument were assigned to a double-precision floating-point
column or variable.
Character string to double
DOUBLE (StringExpression )
- StringExpression
- The argument can be of type CHAR or VARCHAR in the form of a numeric constant.
Leading and trailing blanks in argument are ignored.
The result of the function is a double-precision floating-point
number. The result can be null; if the argument is null, the result is the
null value. The result is the same number that would occur if the string was
considered a constant and assigned to a double-precision floating-point column
or variable.