CodeIgniter Active Record - Get number of returned

问题:

I'm very new to CodeIgniter and Active Record in particular, I know how to do this well in normal SQL but I'm trying to learn.

How can I select some data from one of my tables, and then count how many rows are returned using CodeIgniters Active Record class?

Thanks, Tom.

回答1:

Have a look at the result functions here:

$this->db->from('yourtable');
[... more active record code ...]
$query = $this->db->get();
$rowcount = $query->num_rows();

回答2:

AND, if you just want to get a count of all the rows in a table

$table_row_count = $this->db->count_all('table_name');

回答3:

This goes to you model:

public function count_news_by_category($cat)
{
    return $this->db
        ->where('category', $cat)
        ->where('is_enabled', 1)
        ->count_all_results('news');
}

It'a an example from my current project.

According to benchmarking this query works faster than if you do the following:

$this->db->select('*')->from('news')->where(...); 
$q = $this->db->get(); 
return $q->num_rows();

回答4:

If you only need the number of rows in a query and don't need the actual row data, use count_all_results

echo $this->db
       ->where('active',1)
       ->count_all_results('table_name');

回答5:

Just gotta read the docs son!

$query->num_rows();

回答6:

You can do this in two different ways:

  1. $this->db->query(); //execute the query
     $query = $this->db->get() // get query result
     $count = $query->num_rows() //get current query record.

  2.  $this->db->query(); //execute the query
      $query = $this->db->get() // get query result
      $count = count($query->results()) 
          or   count($query->row_array())  //get current query record.

回答7:

This is also a very useful function if you are looking for a rows or data with where condition affected

function num_rows($table)
    {   
       return $this->db->affected_rows($table);
    }

回答8:

$this->db->select('count(id) as rows');
$this->db->from('table_name');
$this->db->where('active',1);
$query = $this->db->get();
foreach($query->result() as $r)
{
   return $r->rows;
}

回答9:

This code segment for your Model

function getCount($tblName){
    $query = $this->db->get($tblName);
    $rowCount = $query->num_rows();
    return $rowCount;       
}

This is for controlr

  public function index() {
    $data['employeeCount']= $this->CMS_model->getCount("employee");
    $this->load->view("hrdept/main",$data);
}

This is for view

<div class="count">
  <?php echo $employeeCount; ?>                                                                                            
 </div>

This code is used in my project and is working properly.

回答10:

function getCount(){
    return $this->db->get('table_name')->num_rows();
}