PreparedStatement IN clause alternatives?

Question

What are the best workarounds for using a SQL IN clause with instances of java.sql.PreparedStatement, which is not supported for multiple values du

Answer 1

Generate the query string in the PreparedStatement to have a number of ?'s matching the number of items in your list. Here's an example:

public void myQuery(List items, int other) {
  ...
  String q4in = generateQsForIn(items.size());
  String sql = "select * from stuff where foo in ( " + q4in + " ) and bar = ?";
  PreparedStatement ps = connection.prepareStatement(sql);
  int i = 1;
  for (String item : items) {
    ps.setString(i++, item);
  }
  ps.setInt(i++, other);
  ResultSet rs = ps.executeQuery();
  ...
}

private String generateQsForIn(int numQs) {
    String items = "";
    for (int i = 0; i < numQs; i++) {
        if (i != 0) items += ", ";
        items += "?";
    }
    return items;
}