@Override
    @Nullable
    public Boolean getValue(ResultSet rs, int startIndex) throws SQLException {
        String str = rs.getString(startIndex);
        return str != null ? str.equalsIgnoreCase("T") : null;
    }
{@code TrueFalseType} maps Boolean to 'T'/'F' on the JDBC level

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