How the IS_IPV6() function works in Mariadb?

The MariaDB IS_IPV6() function is used to check whether a given string represents a valid IPv6 address. This function is crucial in environments where IPv6 addresses are used, ensuring that data stored and retrieved is formatted correctly for IPv6 standards.

Syntax

The syntax for the IS_IPV6() function in MariaDB is as follows:

IS_IPV6(expr)

• expr is the expression representing the IP address to be checked.

The function returns 1 if expr is a valid IPv6 address, otherwise, it returns 0.

Examples

Example 1: Valid IPv6 Address

To demonstrate checking a valid IPv6 address:

SELECT IS_IPV6('2001:0db8:85a3:0000:0000:8a2e:0370:7334');

The output for this statement is:

+----------------------------------------------------+
| IS_IPV6('2001:0db8:85a3:0000:0000:8a2e:0370:7334') |
+----------------------------------------------------+
|                                                  1 |
+----------------------------------------------------+

This indicates that the provided string is a valid IPv6 address.

Example 2: Invalid IPv6 Address

To show what happens when the address is not valid:

SELECT IS_IPV6('12345');

The output for this statement is:

+------------------+
| IS_IPV6('12345') |
+------------------+
|                0 |
+------------------+

This result signifies that ‘12345’ is not a valid IPv6 address.

Example 3: IPv4 Address

To check an IPv4 address using the IS_IPV6() function:

SELECT IS_IPV6('192.168.1.1');

The output for this statement is:

+------------------------+
| IS_IPV6('192.168.1.1') |
+------------------------+
|                      0 |
+------------------------+

Since ‘192.168.1.1’ is an IPv4 address, the function returns 0.

Example 4: Empty String

Checking an empty string to see if it is considered a valid IPv6 address:

SELECT IS_IPV6('');

The output for this statement is:

+-------------+
| IS_IPV6('') |
+-------------+
|           0 |
+-------------+

An empty string is not a valid IPv6 address.

Example 5: IPv6 Address with Zone Index

Checking an IPv6 address that includes a zone index:

SELECT IS_IPV6('fe80::1ff:fe23:4567:890a%eth0');

The output for this statement is:

+------------------------------------------+
| IS_IPV6('fe80::1ff:fe23:4567:890a%eth0') |
+------------------------------------------+
|                                        0 |
+------------------------------------------+

The function correctly identifies the string as a valid IPv6 address, even with the zone index.

Related Functions

Below are a few functions related to the MariaDB IS_IPV6() function:

• MariaDB INET6_ATON() function is used to convert an IPv6 address into its binary representation.
• MariaDB INET6_NTOA() function is used to convert a binary representation of an IPv6 address back into a human-readable string.

Conclusion

The IS_IPV6() function is a simple yet powerful tool in MariaDB that helps in validating IPv6 addresses. It is especially useful when ensuring that data conforms to IPv6 standards, which is increasingly important as the internet transitions from IPv4 to IPv6. Understanding and utilizing this function can help maintain data integrity and compatibility in network-related database operations.