Your issue here, not going to far into scripting, with the script is that you didn't use @item correctly.
while input @item is ok, 1, it's not a string, so only numbers work, so you'd need to use input @item$, while I personally would use .@item$.
2, in the query you used, it doesn't know what @item is because you incorrectly placed it. It should be:
query_sql "SELECT `id`,`name_english` FROM `item_db` WHERE `name_english` LIKE "+.@item$, .@itemid, .@liste$;
Also unless you renamed your sql db to be named itemdb, it should be item_db, and you defined 2 variables to be selected, so unless you put them into variables, your map server will hate you, so add .@itemid.
The sql query above should work. Take note however that I modified @item to be .@item$ and @liste to be .@list$