Writing SQL Queries in Codeigniter 2.0 - php

Question

I have the following function that does not work and I'm having the hardest time trying to figure it out. I'm 12 and just learning, so forgive me:
function get_answer() {
$answer = $this->db->query("SELECT COUNT(questions) FROM possible_quest WHERE questions='something'");
return $answer;
}
When I run the following SQL query in phpmyadmin, it returns the expected result
SELECT COUNT(questions) FROM possible_quest WHERE questions='something'
How do I get this working in CodeIgniter using my function above?
The PHP error I get is
A PHP Error was encountered
Severity: 4096
Message: Object of class CI_DB_mysql_result could not be converted to string

Answer 1

Could be:
function get_answer()
{
$query = $this->db->query("SELECT COUNT(questions) AS count FROM possible_quest WHERE questions='something'");
$count = $query->row(); // returns an object of the first row
return $count->count;
// OR
$count = $query->row_array(); // returns an asociative array of the result
return $count['count'];
}
Another thing: if you want to pass 'something' as a variable, you can use parametrized query, like
$sql = "SELECT COUNT(questions) AS count FROM possible_quest WHERE questions = ?";
$query = $this->db->query($sql, array($something));
which has the benefit of escaping automatically your variable, so you don't worry about sql injections.

Answer 2

You need to setup to the count.
Heres what you need to do is
$answer = $this->db->query("SELECT COUNT(questions) as count FROM possible_quest WHERE questions='something'")->first_row()->count;
//$answer is now setup to be count
One line. Thats the beauty of CI

Answer 3

You're getting that error because
return $answer;
should be
return $answer->result();

Answer 4

The error you are getting is related to the fact that $this->db->query returns a result object, so you cannot use $answer directly as a string.
I suggest that you use print_r($answer) to see what could be going wrong with your conversion of objects to strings, if you have such a function in your model.

Answer 5

CodeIgniter has functions for building queries and returning the count:
function get_answer() {
$this->db->from("possible_quest");
$this->db->where("questions", "something");
return $this->db->count_all_results();
}
NOTE: The name of the function 'get_answer' doesn't match what you're actually doing. It looks like you're getting a count of questions, not an answer, so you should name it to something that makes more sense, like 'get_question_count'.

Answer 6

I recommend you to use an Active Record with method chaining when possible:
public function getAnswer() {
return
$this->db->
select('id')->
where('questions', 'something')->
get('possible_quest')->row()->count
;
}
or
public function getAnswer() {
return
$this->db->
select('id')->
from('possible_quest')->
where('questions', 'something')->
get()->row()->count
;
}
It's secure, easy to use, easy to understand and read. Don't listen to people saying that a single-line code is something good because a good code should be readable.