Quick Question - DB - Active Record and NULL values

[eluser]MEM[/eluser]
Hello,


I had this working:

Code:

$query=$this->db->get_where('category', array('parent_id_cat'=>NULL));

I wanted to add more where clauses on it:

Code:

$this->db->where('activa_cat =', 1);
$this->db->where('parent_id_cat =', NULL);

But this last line gives me an error. He is not accepting the NULL param.


What am I doing wrong?


Regards,
Márcio

[eluser]bretticus[/eluser]
[quote author="MEM" date="1251573840"]Hello,


I had this working:

Code:

$query=$this->db->get_where('category', array('parent_id_cat'=>NULL));

But this last line gives me an error. He is not accepting the NULL param.


What am I doing wrong?[/quote]

If the first form works, then add another element to your array. Otherwise, you can tell Active Record not to meddle with the where clause statement:

Code:

$this->db->where('parent_id_cat IS NULL', NULL, FALSE);

[eluser]MEM[/eluser]
[quote author="bretticus" date="1251574914"]
If the first form works, then add another element to your array.[/quote]
Yes, but the fact that I wanted to use get->where() instead, was to avoid a large array when I have more then 3 or 4 where clauses.


[quote author="bretticus" date="1251574914"]Otherwise, you can tell Active Record not to meddle with the where clause statement:

Code:

$this->db->where('parent_id_cat IS NULL', NULL, FALSE);

[/quote]

If I get you right,
By using IS NULL instead of = NULL - AND - by passing values to the others Where() method parameters, I'm telling Active Record to not mess with where statement?


Thanks for your reply,
Márcio

[eluser]MEM[/eluser]
Ok, I believe is solved:

Instead of:

Code:

$this->db->where('parent_id_cat =', NULL);

We can take out the = sign:

Code:

$this->db->where('parent_id_cat', NULL);

Regards,
Márcio

[eluser]bretticus[/eluser]
[quote author="MEM" date="1251576376"]


[quote author="bretticus" date="1251574914"]

Code:

$this->db->where('parent_id_cat IS NULL', NULL, FALSE);

[/quote]

If I get you right,
By using IS NULL instead of = NULL - AND - by passing values to the others Where() method parameters, I'm telling Active Record to not mess with where statement?
Márcio[/quote]

IS NULL is noting more than my preference but making the last parameter of where() FALSE is where is where you tell AR not to mes with the clause you send.

$this->db->where() accepts an optional third parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names with backticks.

Code:

$this->db->where('MATCH (field) AGAINST ("value")', NULL, FALSE);

[eluser]MEM[/eluser]
I didn't know about that backticks option.
I still need to properly understand how the use of '' can protect or meddle with our queries. But that's a question I should solve outside CI scope.

Thanks for your time,
Márcio