In both SQL and most programming languages, 0.00 and 0 are considered equal. Although they are represented differently (one as a floating-point number with two decimal places and the other as an integer), they both denote the same value. When comparing numbers, 0.00 == 0 evaluates to TRUE. Below is a detailed explanation and important considerations:

1. Comparison in SQL

In SQL, when comparing numeric fields, 0.00 and 0 are treated as equal because they both represent zero. Database systems like MySQL and PostgreSQL do not differentiate between integers and floating-point numbers in this case; as long as the numeric value is the same, they are considered equal. For example:

SELECT CASE
    WHEN 0.00 = 0 THEN 'True'
    ELSE 'False'
END AS comparison_result;

Output:

comparison_result
-----------------
True

Whether 0 is of type INT or 0.00 is of type FLOAT or DOUBLE, they are equal as long as their values are the same.

2. Comparison in Programming Languages

In programming languages like C++, Python, and Java, numerical comparison also does not distinguish between integers and floating-point numbers. As long as the values are identical, they are considered equal. For instance:

C++ Example

#include <iostream>

int main() {
    double d = 0.00;
    int i = 0;
    if (d == i) {
        std::cout << "0.00 is equal to 0" << std::endl;
    } else {
        std::cout << "0.00 is not equal to 0" << std::endl;
    }
    return 0;
}

Output:

0.00 is equal to 0

3. Precision Considerations with Floating-Point Numbers

While 0.00 and 0 are generally treated as equal, it’s important to be mindful of precision when working with floating-point numbers (FLOAT or DOUBLE). When floating-point numbers contain very small decimal parts, precision errors can occur. In cases where two floating-point values are very close but not exactly equal, it’s best to use a small tolerance (like epsilon) for comparison.

Example

#include <iostream>
#include <cmath>

int main() {
    double d1 = 0.00;
    double d2 = 0.0000001;
    if (std::abs(d1 - d2) < 1e-6) { // Use a small tolerance value
        std::cout << "d1 is approximately equal to d2" << std::endl;
    } else {
        std::cout << "d1 is not equal to d2" << std::endl;
    }
    return 0;
}

4. Summary

• In SQL and most programming languages, 0.00 and 0 are considered equal since they both represent the numeric value zero.
• When working with floating-point numbers, precision issues should be taken into account. If values are very close but not exactly equal, using a tolerance value for comparison can help avoid errors.