Querying the ContentProvider for certain IDs

Question

I have a contacts table and I need to get only certain IDs.

Imagine I have 10 contacts with ids from 1 to 10 and I want to get a Cursor with contacts 1 and 2.

A working code would be:

new CursorLoader(MyContentProvider.CONTACT_CONTENT_URI, null,
MyContentProvider.CONTACT_COLUMN_ID + " IN  ( 1, 2 )",
null, null);

My problem is that I am unable to use the selectionArgs parameter since the escaping would break the query.

Can you think of a way of using the selectionArgs parameters and making this work?

Answer 1

If you want to use selectionArgs you can only use it like

String selection = "column IN (?, ?, ?)";
String[] selectionArgs = { "1", "2", "3" };

You need to build the "( ?, ?, ? )" string based on the number of arguments at runtime though. E.g.

private static String getSelection(int args) {
    StringBuilder sb = new StringBuilder(MyContentProvider.CONTACT_COLUMN_ID + " IN  (");
    boolean first = true;
    for (int i = 0; i < args; i ++) {
        if (first) {
            first = false;
        } else {
            sb.append(',');
        }
        sb.append('?');
    }
    sb.append(')');
    return sb.toString();
}