[Calgon]

pawn Code:

new string[256];
format(string,sizeof(string),"UPDATE `users` SET `fieldname` = '%s' WHERE `username` = '%s'",string to update);
mysql_query(string);

In MySQL, you're obviously going to need to create large strings for queries, but you shouldn't specify examples of bad practice, seeing as that is an extremely small/minor query, you should really refrain from using 256-cell strings (4 bytes per cell... 1024 bytes per messy string).