Which datatype is used to store IP address in SQL server?

 In SQL Server, the DATETIME or VARCHAR types are not ideal for storing IP addresses, but rather, you should use the INET4 or INET6 type if you want to store IPv4 or IPv6 addresses directly. However, if you're working with an older version of SQL Server, or you want to store the IP address as an integer or string, there are several options:

1. VARCHAR(15) or CHAR(15):

   • For IPv4 addresses, which are typically in the format xxx.xxx.xxx.xxx, you can use VARCHAR(15) or CHAR(15). This is enough to store an IPv4 address (maximum 15 characters long).

   Example:

   CREATE TABLE Users (
       UserID INT,
       IPAddress VARCHAR(15)
   );
   

2. BIGINT (for storage as an integer):

   • IPv4 addresses can also be stored as a 32-bit integer by converting the address to a numeric format (using functions like INET_ATON or similar, if you use custom functions). In this case, BIGINT would be used to store the address in its integer representation.

3. VARBINARY(16):

   • For storing both IPv4 and IPv6 addresses in a more compact binary format, VARBINARY(16) is suitable. An IPv4 address would take up 4 bytes, and an IPv6 address would take up 16 bytes.

   Example for IPv6:

   CREATE TABLE Users (
       UserID INT,
       IPAddress VARBINARY(16)
   );
   

4. CIDR (in certain cases with extensions):

   • Some SQL Server extensions or third-party tools might allow storing IP addresses with a CIDR format. However, this would require extra setup beyond native SQL Server support.

Example of storing an IPv4 address as a string:

CREATE TABLE NetworkData (
    DeviceID INT,
    DeviceIP VARCHAR(15)  -- IPv4 address
);

In summary, for compatibility with most SQL Server versions, VARCHAR(15) is a typical choice for storing IPv4 addresses, while VARBINARY(16) is used for both IPv4 and IPv6.