CONCAT() between different alphabet echoes out '&' ampersand I want to concatenate different alphabet strings and get a weird latin encoding with ampersands after the sixth greek character (I want to concatenate greek and english alphabet strings).

Lets say I have :

COL 1   COL 2
John    Johnson

and instead of John Johnson i get John Johnso&amp;adasdasa

any help ?
You can use COLLATE : 

concat(COL1 COLLATE latin1_general_ci,COL2 COLLATE latin1_general_ci)

latin1_general_ci is an example, try to figure it out what collation do u have.

But i think this should work, you could try latin1_general_cs too.