How to check if id already exists - codeigniter - php

Question

i am trying to check if an id in the database already exists and if it does not then only insert that id and not the other ones that exist
I have tried to do a where statement that checks if their is a id exists in the database but even if their are new information it does not insert it into the database
Im quite lost here
any guidance would be appreciated
ps i dont want to update a row i want to insert a new updated one that does not exist
$this->db->where('id',$id);
$q = $this->db->get('testing');
if($q)
{
//Do nothing
}
else
{
$this->db->set('id', $id);
$this->db->set('message', $message);
$query= $this->db->insert('testing');
}

Answer 1

Model
<?php
class Fruits_model extends CI_Model
{
function __construct()
{
parent::__construct();
$this->load->database();
}
function check()
{
$query = null; //emptying in case
$id = $_POST['id']; //getting from post value
$name = $_POST['name'];
$query = $this->db->get_where('fruits', array(//making selection
'id' => $id
));
$count = $query->num_rows(); //counting result from query
if ($count === 0) {
$data = array(
'name' => $name,
'id' => $id
);
$this->db->insert('fruits', $data);
}
}
}
?>

Answer 2

You have a logic issue with your code that you need to fix.
In your code, you save the result from your query as $q = $this->db->get('testing'),
and $q will always evaluate to true regardless of the number of rows your return.
You need to check the number of rows using $query->num_rows() > 0 and then the rest
of you code will behave as you expect.
For more details, see: http://ellislab.com/codeigniter/user-guide/database/results.html

Answer 3

$ql = $this->db->select('id')->from('testing')->where('id',$id)->get();
if( $ql->num_rows() > 0 ) {} else {
$a = array('id' => $id, 'message' => $message);
$this->db->insert('testing', $a);
}
This should do it.

Answer 4

You should try like this:
public function record_exists(){
$exists = $this->db->get_where('table_name', array('id' => $id));
if($exists->num_rows() > 0 ){
echo "Some message";
return false;
}else{
// Insert your data into the database...
}
}

Answer 5

You need to select the id's in your MYSQL table with the id you want to check and then count the rows. If the row count is 0 then the id doesn't exist.
$query = mysql_query("SELECT * FROM your_table WHERE id='$id'");
$count = mysql_num_rows($query);
If($count!=0){
// id exists
} else {
// id doesn't exist
}

Answer 6

normally 'id' field is set with auto_increment and set primary which is unique and not repeatable. So there is not problem to worry about existing.
However, in your case I think you are not using it as a 'unique field'.
Let me give you an example.
Here I have a table name 'fruits'
++++++++++++++++++++++++++++++++++++
ငfruit_id | int (primary)
name | text
id | int
++++++++++++++++++++++++++++++++++++++
in your model
function checkId($id)
{
$query=$this->db->get_where('fruits',array('id'=>$id)); //check if 'id' field is existed or not
if($query!=null) // id found stop
{
return FALSE;
}
else // id not found continue..
{
$data = array(
'fruit_id' => $fruit_id ,
'name' => $name ,
'id' => $id
);
$this->db->insert('fruits', $data);
}
}

Answer 7

For Checking An Id Or any column value exist not in database CI have a validation rule for it.
See it live here: Validation Rule
Rule: is_unique
Returns FALSE if the form element is not unique to the table and field name in the parameter. Note: This rule requires Query Builder to be enabled in order to work.
Example: is_unique[table.field]
$this->form_validation->set_rules(
'username', 'Username',
'required|min_length[5]|max_length[12]|is_unique[users.username]',
array(
'required' => 'You have not provided %s.',
'is_unique' => 'This %s already exists.'
)
);
For More Advance use of validation, You can add all validation Setting Rules Using an Array.
$this->form_validation->set_rules(
'username', 'Username',
'required|min_length[5]|max_length[12]|is_unique[users.username]',
array(
'required' => 'You have not provided %s.',
'is_unique' => 'This %s already exists.'
)
);
$config = array(
'your_rule_name' => array(
array(
'username', 'Username',
'required|min_length[5]|max_length[12]|is_unique[users.username]',
array(
'required' => 'You have not provided %s.',
'is_unique' => 'This %s already exists.'
)
)
),
array(
'field' => 'email',
'label' => 'Email',
'rules' => 'required'
)
);
$this->form_validation->set_rules($config);