DOUBLE

Description

64-bit binary floating-point (DOUBLE) is a numerical data type used to represent real numbers, capable of storing very large or very small values. In computer systems, 64-bit floating-point numbers follow the IEEE 754 standard, providing approximately 15-17 digits of precision.

Syntax

DOUBLE

Example

1. Return the 64-bit floating-point representation of the positive integer 1:

   SELECT +1D;
   

2. Convert the integer -6 to a 64-bit floating point representation:

   SELECT CAST(-6 AS DOUBLE);
   

3. Return the value 1.99714E+13 in scientific notation:

   SELECT 1.99714E+13;
   

4. Convert string floating-point numbers to 64 bit floating-point numbers:

   SELECT CAST('123.456' AS DOUBLE);
   

5. Calculate the sum of two 64-bit floating-point numbers:

   SELECT CAST(123.45 AS DOUBLE) + CAST(678.91 AS DOUBLE);
   

6. Compare the size of two 64-bit floating-point numbers:

SELECT CAST(123.456 AS DOUBLE) > CAST(122.345 AS DOUBLE);

7. Calculate the square root of a 64-bit floating point number:

   SELECT SQRT(CAST(16 AS DOUBLE));
   

Precautions

• FLOAT or DOUBLE. This is because the representation of floating-point numbers in computers may lead to precision loss, resulting in inaccurate outcomes during comparison and association operations,