Do you looking for how to store above 20 digit integer number in MySQL ? Seems like
BIGINT is the biggest integer available on MySQL, right? What to do when you need to store a
BIGINT(80) for example?
Big integers aren’t actually limited to 20 digits, they’re limited to the numbers that can be expressed in 64 bits (for example, the number
99,999,999,999,999,999,999 is not a valid big integer despite it being 20 digits long).
The reason you have this limitation is that native format integers can be manipulated relatively fast by the underlying hardware whereas textual versions of a number (tend to) need to be processed one digit at a time.
If you want a number larger than the largest 64-bit unsigned integer
18,446,744,073,709,551,615, then you will need to store it as a
varchar (or other textual field) and hope that you don’t need to do much mathematical manipulation on it.
Alternatively, you can look into floating point numbers which have a larger range but less precision, or decimal numbers which should be able to give you 65 digits for an integral value, with
decimal(65,0) as the column type. The reason to select one over another is usage, efficiency and space. Using an int is more efficient than a bigint or, I believe, decimal If you need to do math on it.
ALTER TABLE `table_name` CHANGE `column_name` `column_name` DECIMAL(65,0) UNSIGNED NOT NULL DEFAULT '1';