Getting auto-generated key from row insertion in spring 3 / PostgreSQL 8.4.9

The easiest way to get a key back from an INSERT with Spring JDBC is to use the SimpleJdbcInsert class. You can see an example in the Spring Reference Guide, in the section titled Retrieving auto-generated keys using SimpleJdbcInsert.

KeyHolder holder = new GeneratedKeyHolder();

getJdbcTemplate().update(new PreparedStatementCreator() {           

                @Override
                public PreparedStatement createPreparedStatement(Connection connection)
                        throws SQLException {
                    PreparedStatement ps = connection.prepareStatement(sql.toString(),
                        Statement.RETURN_GENERATED_KEYS); 
                    ps.setString(1, person.getUsername());
                    ps.setString(2, person.getPassword());
                    ps.setString(3, person.getEmail());
                    ps.setLong(4, person.getRole().getId());
                    return ps;
                }
            }, holder);

Long newPersonId = holder.getKey().longValue();

Note that in newer versions of Postgres you need to use

connection.prepareStatement(sql.toString(), 
    new String[] { "idcompte" /* name of your id column */ })

instead of

connection.prepareStatement(sql.toString(), 
    Statement.RETURN_GENERATED_KEYS);

I'm using Spring3.1 + PostgreSQL9.1, and when I use this

    KeyHolder keyHolder = new GeneratedKeyHolder();
    jdbcTemplate.update(new PreparedStatementCreator() {
        public PreparedStatement createPreparedStatement(Connection connection)
                throws SQLException {
            PreparedStatement ps = 
                connection.prepareStatement(youSQL, 
                    Statement.RETURN_GENERATED_KEYS);
            ps.setString(1, post.name_author);
            ...
            return ps;
        }
    }, keyHolder);
    long id = keyHolder.getKey().longValue();

I got this exception:

 org.springframework.dao.InvalidDataAccessApiUsageException: 
The getKey method should only be used when a single key is returned.  
The current key entry contains multiple keys: ...

So I changed to :

PreparedStatement ps = 
connection.prepareStatement(youSQL, new String[]{"id"});

where "id" is

id serial not null primary key

And the problem is solved. So I supposed that using

prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

is not right here. The official guide is here, Chapter 13.2.8 :Retrieving auto-generated keys