How to get ID of inserted record in database ?

Some database operations, especially those involving parent-child relationships (one-to-many), you may want to insert a record into the parent table first, then into the child table. 

But the records in the child table must have a foreign key that refers to the parent table’s primary key.

In such case, you need a technique that retrieves the value of the primary key of the last record inserted (in case, when ID is auto-incremented by the database engine).

For MySQL and Java Derby database

String sql = "YOUR INSERT STATEMENT HERE";

PreparedStatement ps = 

      conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

ps.execute();

ResultSet rs = ps.getGeneratedKeys();

int generatedKey = 0;

if (rs.next()) {

  generatedKey = rs.getInt(1);

}

System.out.println("Inserted record's ID: " + generatedKey); 

For Oracle database

PreparedStatement statement = 

      conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

statement.execute();

PreparedStatement ps = connection.prepareStatement(

            "select your_table_id_sequence.currval from dual");

ResultSet rs = ps.executeQuery();

if (rs.next()) {

  generatedKey = (int) rs.getLong(1);

}

System.out.println("Inserted record's ID: " + generatedKey);

Note : For Oracle database, you should create a sequence for the table’s primary key.