Codeigniter ActiveRecord：加入反引号

Question

I've a simple question: how can I use CodeIgniter's ActiveRecord join function? I want this:

LEFT JOIN cimke ON (mk_terem.id_kicsoda=5 AND mk_terem.id_target=cimke.id_cimke)
LEFT JOIN tanar ON (mk_terem.id_kicsoda=1 AND mk_terem.id_target=tanar.id_tanar)

But if I use $this->db->join(cimke,"mk_terem.id_kicsoda=5 AND mk_terem.id_target=cimke.id_cimke") , the value 5 will be between backticks.

How can I do this?

UPDATE

What I want? If mk_terem.id_kicsoda is 1, then I want tanar.nev and when mk_terem.id_kicsoda is 5, I want cimke.nev .

The full SQL-query:

SELECT
terem.nev terem_nev,
elem_tipus.nev tipus_nev,
(IFNULL(cimke.nev,tanar.nev)) nev
FROM mk_terem
LEFT JOIN terem ON mk_terem.id_terem=terem.id_terem
LEFT JOIN cimke ON (mk_terem.id_kicsoda=5 AND mk_terem.id_target=cimke.id_cimke)
LEFT JOIN tanar ON (mk_terem.id_kicsoda=1 AND mk_terem.id_target=tanar.id_tanar)
LEFT JOIN elem_tipus ON (mk_terem.id_kicsoda=elem_tipus.id_kicsoda)

Answer 1

Only a simple workaround, ugly, not elegant, but it works in this case:

$original_reserved = $this->db->_reserved_identifiers;
$this->db->_reserved_identifiers[] = 5;
$this->db->_reserved_identifiers[] = 1;
// or any other values
$this->db->join('with critical values and conditions');
// some db-stuff
$this->db->_reserved_identifiers = $original_reserved;

If anybody knows better please show it!

Answer 2

$this->db->join('cimke', 'mk_terem.id_target = cimke.id_cimke');
$this->db->join('tanar', 'mk_terem.id_target = tanar.id_tanar');
$this->db->where('mk_terem.id_kicsoda', 5);
$this->db->where('mk_terem.id_kicsoda', 1);

or use

$this->db->query('AND_YOUR_RAW_SQL_QUERY_HERE');

Answer 3

I know i am very answering this question very late. Just i am sharing my knowledge. It may help us to known something. If I am wrong, Please tell me. I am answering this question by the full query you posted on your question. Kindly check it below.

$this->db->from('mk_terem');
$this->db->select('terem.nev terem_nev, elem_tipus.nev tipus_nev, (IFNULL(cimke.nev,tanar.nev)) nev');
$this->db->join('terem','mk_terem.id_terem=terem.id_terem','left');
$this->db->join('cimke','(mk_terem.id_kicsoda=5 AND mk_terem.id_target=cimke.id_cimke)','left');
$this->db->join('tanar','(mk_terem.id_kicsoda=1 AND mk_terem.id_target=tanar.id_tanar)','left');
$this->db->join('elem_tipus','(mk_terem.id_kicsoda=elem_tipus.id_kicsoda)','left'); $this->db->get();

I got the query which you posted in the question as full Query. Check it below.

SELECT `terem`.`nev` terem_nev, `elem_tipus`.`nev` tipus_nev, (IFNULL(cimke.nev, `tanar`.`nev))` nev FROM (`mk_terem`) LEFT JOIN `terem` ON `mk_terem`.`id_terem`=`terem`.`id_terem` LEFT JOIN `cimke` ON `mk_terem`.`id_kicsoda`=`5` AND mk_terem.id_target=cimke.id_cimke) LEFT JOIN `tanar` ON `mk_terem`.`id_kicsoda`=`1` AND mk_terem.id_target=tanar.id_tanar) LEFT JOIN `elem_tipus` ON `mk_terem`.`id_kicsoda`=`elem_tipus`.`id_kicsoda)`

I believe everything is possible to do by codeignitor Active record. No need to execute the query in $this->db->query() as raw sql.

@uzsolt: I am explaining this because of the argument you made under the topic "http://stackoverflow.com/questions/8344769/writing-sql-queries-in-codeigniter-2-0". And I will try your other bugs you posted under the above URL too shortly and get back to you. If i am anything wrong, kindly let me know. Thanks. :)

Answer 4

Another simple solution would be to temporarily set the protect_identifiers off like so:

$this->db->_protect_identifiers = false;

After making the query you could set it back to true

Answer 5

If you swap the conditions around AND, it will work! CodeIgniter only escapes the first part of the condition. So, inthis should work:

$this->db->join('cimke',"mk_terem.id_kicsoda = 5 AND mk_terem.id_target = cimke.id_cimke", "left")