在codeigniter中将两列连接到一列

Question

I have been searching and still feel lost.

My sql DB is like this
bf_putnr -> colums: PUTNR_ID|PUTNR
Data:
PUTNR_ID PUTNR
1 put_1
2 put_2
3 put_12
4 put_28
5 put_34

bf_rioo -> colums: RIOO_ID|PUTA|PUTB
RIOO_ID PUTA PUTB
1 put_1 put_2
2 put_1 put_28
3 put_12 put_1


PUTA and PUTB are the same as PUTNR in the table bf_putnr

in codeigniter i'd like to get the PUTNR_ID when getting all the bf_rioo data

This is what i came up with,

                $this->db->from('bf_rioo');

                $this->db->join('bf_putnr AS A', 'bf_rioo.PUTA = A.putnr');
                $this->db->join('bf_putnr AS B', 'bf_rioo.PUTB = B.putnr');

but it only returns the second join. I think the second join is overwriting the data from the first one. I get all colums from bf_rioo and all columns from bf_putnr but only joined on the last join statement.....?

How do i get the join on putnr to return the data for PUTA and PUTB ??

Answer 1

You can use both join conditions in the same join statements.

$this->db->from('bf_rioo');
$this->db->join('bf_putnr AS A', 'bf_rioo.PUTA = A.putnr AND bf_rioo.PUTB = A.putnr);