Whenever a filed is INT(data type), what must i choose as collation in MySQL?

Collation affects string sorting. It does not work on number data types.

It might, howevever, impact how amounts baked into strings are sorted. But that is still no impact on number data types for example INT.

So far as I understand, you are able to specify a collation (or perhaps a character set for your matter) just for string types, ie. the kinds VARCHAR, CHAR, ENUM, SET, and TEXT types (TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT)

Roland Bouman http://rpbouman.blogspot.com/