No operator matches the given name and argument type(s). You might need to add explicit type casts. -- Netbeans, Postgresql 8.4 and Glassfish

I had this issue, and solved. This was due to the WHERE clause contains String value instead of integer value.

This the main error:

ERROR: operator does not exist: integer = character varying

You code is trying to match an integer and a string, that's not going to work. Fix your code, get the query that is involved to see if you fixed it. See also the PostgreSQL log files.

A workaround (NOT A SOLUTION!) is to do some casting. Check this article.

Doesn't look like you got an answer but this problem can also creep up if you're passing null ID's into your JPA Predicate.

For instance.

If I did a query on Cats to get back a list. Which returns 3 results.

List catList;

I then iterate over that List of cats and store a foriegn key of cat perhaps leashTypeId in another list.

List<Integer> leashTypeIds= new ArrayList<>();for(Cats c : catList){    leashTypeIds.add(c.getLeashTypeId);}jpaController().findLeashes(leashTypeIds);

If any of the Cats in catList have a null leashTypeId it will throw this error when you try to query your DB.

(Just realized I am posting on a 5 year old thread, perhaps someone will find this useful)