So I've been testing this out for a day or so. For the life of me I cannot get an external list to listen to honor the
<In> operator in CAMLQuery. On any other type of list it seems to work great. I happen to be using SPServices to query the list, but as I mentioned, it works fine with other types of lists.
CAMLQuery: "<Query><Where><In><FieldRef Name='ParentID' /><Values><Value Type='Text'>70005030</Value><Value Type='Text'>70005031</Value></Values></In></Where></Query>",
I don't think it's an SPServices issue. Is this a limitation of external content type lists? There is no "Title" field in my external list, would this be an issue?