Searching multidimensional array for values, then outputting other values in array

Question

Hi all,

I'm wondering how I might go about searching the array below for the key problem_id and a value equal to a variable which I would provide. Then, when it finds an array with a the matching key and variable, it outputs the other values in that part of the array too.

For example, using the sample data below. How would you recommend that I search the array for all the arrays that have the key problem_id and the value 3 and then have it output the value of the key problem_update_date and the value of the key problem_update_text. Then keep searching to find the next occurrence?

Thanks in advance, I've been searching really hard for the answer and believe i'm over my head!

Output of print_r($updates);

CI_DB_mysql_result Object
(
  [conn_id] => Resource id #30
  [result_id] => Resource id #35
  [result_array] => Array()
  [result_object] => Array()
  [current_row] => 0
  [num_rows] => 5
  [row_data] => 
)

Output of print_r($updates->result_array());

Array
(
  [0] => Array
  (
    [problem_update_id] => 1
    [problem_id] => 3
    [problem_update_date] => 2010-10-01
    [problem_update_text] => Some details about a paricular issue
    [problem_update_active] => 1
  )

  [1] => Array
  (
    [problem_update_id] => 4
    [problem_id] => 3
    [problem_update_date] => 2010-10-01
    [problem_update_text] => Another update about the problem with an ID of 3
    [problem_update_active] => 1
  )

  [2] => Array
  (
    [problem_update_id] => 5
    [problem_id] => 4
    [problem_update_date] => 2010-10-12
    [problem_update_text] => An update about the problem with an ID of four
    [problem_update_active] => 1
  )

  [3] => Array
  (
    [problem_update_id] => 6
    [problem_id] => 4
    [problem_update_date] => 2010-10-12
    [problem_update_text] => An update about the problem with an ID of 6
    [problem_update_active] => 1
  )

  [4] => Array
  (
    [problem_update_id] => 7
    [problem_id] => 3
    [problem_update_date] => 2010-10-12
    [problem_update_text] => Some new update about the problem with the ID of 3
    [problem_update_active] => 1
  )
)

Answer 1

If you just want a list of problem_update for the problem with the id 3 why dont you limit your (my)sql-statemant to retunr only these? WHERE problem.problem_id = 3

anyway:

foreach( $updates->result_array() as $update ) {
    if( 3 == $update['problem_id'] ) {
        echo $update['problem_update_date'] . ' : ' . $update['problem_update_text'];
    }
}

Answer 2

Sorry @maggie. This is almost same as what you wrote, but in function. Hope that will help you. Of course if I understod you correctly.

function youAskedForIt( $some_array = array(), $value_to_search_for ) {

    foreach( $some_array as $value ) {

        if( ! isset( $value['problem_id'] ) || ! isset( $value['problem_update_date'] ) || ! isset( $value['problem_update_text'] ) ) {

            continue;

        }

        if( $value_to_search_for == $value['problem_id'] ) {

            echo $value['problem_update_date'] . ' => ' . $value['problem_update_text'] . "<br>\n";

        }

    }

}

youAskedForIt( $updates->result_array(), 3 );

Answer 3

Maggie is right: you shouldn't look for the key by iterating over the array. Just add project_id = 3 as a condition in SQL.

Either use get_where():

$query = $this->db->get_where('my_table_name', array('problem_id' => 3));

foreach($query->result() as $row)
{
    echo $row->problem_update_date;
    echo $row->problem_update_text;
}

Or where():

$this->db->where('project_id', 3);
$query = $this->db->get('my_table_name');

foreach($query->result() as $row)
{
    echo $row->problem_update_date;
    echo $row->problem_update_text;
}

For more info check the great Codeigniter documentation:

• The Database Class
• Active Record Class