Storing IP addresses in MySQL

1 minute read

Lets say you have an IP address,, and want to store it in a table. The most common method people seem to use it to store it as a CHAR(15).

However, you probably want to search on this column and therefore want an index on it.

MySQL has two built-in functions, INET_ATON() which converts Internet addresses from the numbers-and-dots notation into a 32-bit unsigned integer, and INET_NTOA() which does the opposite.

Putting it to the test:

mysql> SELECT INET_ATON('') AS ipn;
| ipn        |
| 3232235530 |

mysql> SELECT INET_NTOA(3232235530) AS ipa;
| ipa          |
| |

So you can store an IP address in an INT UNSIGNED (4 bytes) which is more efficient and faster than a CHAR(15). Naturally, you can call the function while you’re inserting, so something like this is fine also:

INSERT INTO tbl VALUES (..., INET_ATON(''), ...)

In MySQL 5.0, you can even do this transformation inside a LOAD DATA INFILE command, without using temporary columns:

(col1, ..., @ipa1, ..., coln)
SET ipn = INET_ATON(@ipa);

So in the list of columns you assign this column to a server-side variable, and then assign the transformed value to the proper column in the SET clause.


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