Professional CodeIgniter, Thomas Myer

Chapter 3: A 10,000 - Foot View of CodeIgniter
58

You can even use the
from()

method to tell CodeIgniter which table to select from, like this:
$this-
>
db-
>
select(`id, name, gender');
$this-
>
db-
>
from(`persons');
$Q = $this-
>
db-
>
get();

Furthermore, you can list various
where
provisions using the aptly named
where()
clause:
$this-
>
db-
>
select(`id, name, gender');
$this-
>
db-
>
from(`persons');
$this-
>
db-
>
where(`id', 14);
$this-
>
db-
>
where(`status', `live');
$Q = $this-
>
db-
>
get();
//query becomes:
//select id, name, gender from persons where id=14 and status='live'

You could also get fancy with the
where()

method, passing in operators, such as not equal (
!=

) or less
than (
<
):
$this-
>
db-
>
select(`id, name');
$this-
>
db-
>
from(`persons');
$this-
>
db-
>
where(`id
>
=', 3);
$Q = $this-
>
db-
>
get();
//query becomes:
//select id, name from persons where id
>
= 3

If you ' re impatient or need to pass in a custom
where
string, you can do that too:
$this-
>
db-
>
select(`id, name');
$this-
>
db-
>
from(`persons');
$this-
>
db-
>
where("name='Tom' and id
>
3");
$Q = $this-
>
db-
>
get();
//query becomes:
//select id,name from persons where name='Tom' and id
>
3
The
like()

method generates SQL LIKE clauses, which is extremely useful when building search
functions:
$this-
>
db-
>
select(`id, name');
$this-
>
db-
>
from(`persons');
$this-
>
db-
>
like(`name', `Tom');
$Q = $this-
>
db-
>
get();
//query becomes:
//select id,name from persons where name like `%Tom%'

When doing an insert, first you build a data array and pass that array to the
insert()

method. In many
cases, your data array consists of information from a form, but it could also contain data from a session
or cookie.
c03.indd 58
c03.indd 58
6/10/08 5:33:49 PM
6/10/08 5:33:49 PM


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