@Override
    @Nullable
    public Boolean getValue(ResultSet rs, int startIndex) throws SQLException {
        String str = rs.getString(startIndex);
        return str != null ? str.equalsIgnoreCase("Y") : null;
    }
{@code YesNoType} maps Boolean to 'Y'/'N' on the JDBC level

@author tiwe
querydsl-sql/src/main/java/com/querydsl/sql/types/YesNoType.java