Is ther a way to retrieve the autoincrement ID from a prepared statement

Question

Is there a way to retrieve the auto generated key from a DB query when using a java query with prepared statements.

For example, I know AutoGeneratedKeys can work as follows.

stmt = conn.createStatement();

stmt.executeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
if(returnLastInsertId) {
    ResultSet rs = stmt.getGeneratedKeys();
    rs.next();
    auto_id = rs.getInt(1);
}

However. What if I want to do an insert with a prepared Statement.

String sql = "INSERT INTO table (column1, column2) values(?, ?)";
stmt = conn.prepareStatement(sql);

//this is an error
stmt.executeUpdate(Statement.RETURN_GENERATED_KEYS);
if(returnLastInsertId) {
    //this is an error since the above is an error
    ResultSet rs = stmt.getGeneratedKeys();
    rs.next();
    auto_id = rs.getInt(1);
}

Is there a way to do this that I don't know about. It seems from the javadoc that PreparedStatements can't return the Auto Generated ID.

Answer 1

Yes. See here. Section 7.1.9. Change your code to:

String sql = "INSERT INTO table (column1, column2) values(?, ?)";
stmt = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);


stmt.executeUpdate();
if(returnLastInsertId) {
   ResultSet rs = stmt.getGeneratedKeys();
    rs.next();
   auto_id = rs.getInt(1);
}

Answer 2

Yes, There is a way. I just found this hiding in the java doc.

They way is to pass the AutoGeneratedKeys id as follows

String sql = "INSERT INTO table (column1, column2) values(?, ?)";
stmt = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

Answer 3

There's a couple of ways, and it seems different jdbc drivers handles things a bit different, or not at all in some cases(some will only give you autogenerated primary keys, not other columns) but the basic forms are

stmt = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

Or use this form:

String autogenColumns[] = {"column1","column2"};
stmt = conn.prepareStatement(sql, autogenColumns)