Search Filtering with PHP/MySQL

Question

I\'m trying to create a search/filtering option in my blood donor application. Where donor can be searched by sex, name, blood group or by selecting all three. Here is my code

Answer 1

There in Your code there is problem in query where condition . Here your query will be like select * from donar where by_name = "A" by_group = "N" there is No And/Or to make where condition properly. Please try code like given below.

$search_query = "SELECT * FROM donar";
$query_cond = "";

if($by_name !="") {
      $query_cond .= " name='$by_name'";
}
if($by_sex !="") {

      if(!empty($query_cond)){
          $query_cond .= " AND ";
       }

      $query_cond .= " sex='$by_sex'";
}

if($by_group !="") {

      if(!empty($query_cond)){
          $query_cond .= " AND ";
       }

      $query_cond .= " blood_group='$by_group'";
}

if($by_level !="") {

      if(!empty($query_cond)){
          $query_cond .= " OR ";
       }

      $query_cond .= " e_level='$by_level'";
 }

 if(!empty($query_cond)){
      $query_cond = " Where ".$query_cond;
      $search_query.$query_cond;
 }

Here in code First we take $query_cond variable empty and make condition according code. and manage AND operator according that. And in last if We found $query_cond not empty then add it to $select_query.

I hope it will be helpful for you.

thanks

Answer 2

The following code snippet:

$search_query = "SELECT * FROM donar WHERE";
if($by_name !="") {
  $search_query .= " name='$by_name'";
}
if($by_sex !="") {
  $search_query .= " sex='$by_sex'";
}

produces queries like

SELECT * FROM donar WHERE name='nowak' sex='m'

, which are not valid because there is no logical operator between the clauses. You need to add an 'AND'. To simplify code, you can generate conditions in the form of "true and a and b ...":

$search_query = "SELECT * FROM donar WHERE true";
if($by_name !="") {
  $search_query .= " AND name='$by_name'";
}
if($by_sex !="") {
  $search_query .= " AND sex='$by_sex'";
}
...

Answer 3

function search_donar($_POST) {

    $by_name = $_POST['by_name'];
    $by_sex = $_POST['by_sex'];
    $by_group = $_POST['by_group'];
    $by_level = $_POST['by_level'];

    $search_query = "SELECT * FROM donar WHERE";

    $and = '';
    if(count($_POST) > 1) {
        $and ='AND';
    }
    if($_POST[0]) {
        $and ='';
    }

    if($by_name !="") {
        $search_query .= $and." name='$by_name'";
    }
    if($by_sex !="") {
        $search_query .= $and." sex='$by_sex'";
    }
    if($by_group !="") {
        $search_query .= $and." blood_group='$by_group'";
    }
    if($by_level !="") {
        $search_query .= $and." e_level='$by_level'";
    }

    if(count($_POST) == 0) {
        $search_query .= " 1 ";
    }

    $search_query;
    $result = mysql_query($search_query);

    return $result;
}

Answer 4

I'd do in this way.

function search_donar($_POST) {

    $by_name = $_POST['by_name'];
    $by_sex = $_POST['by_sex'];
    $by_group = $_POST['by_group'];
    $by_level = $_POST['by_level'];

    $search_query = "SELECT * FROM donar WHERE 1 = 1";
    if($by_name !="") {
      $search_query .= " AND name='$by_name'";
    }
    if($by_sex !="") {
      $search_query .= " AND sex='$by_sex'";
    }
    if($by_group !="") {
      $search_query .= " AND blood_group='$by_group'";
    }
    if($by_level !="") {
      $search_query .= " AND e_level='$by_level'";
    }
    $result = mysql_query($search_query);
    return $result;
}

Answer 5

Try like this:

function search_donar($_POST) {

        $by_name = $_POST['by_name'];
        $by_sex = $_POST['by_sex'];
        $by_group = $_POST['by_group'];
        $by_level = $_POST['by_level'];

        $isfirst=0;
        $search_query = "SELECT * FROM donar WHERE";
        if($by_name !="") {

          $search_query .= " name='$by_name'";
          $isfirst=1;
        }
        if($by_sex !="") {
            if($isfirst!=0)
            $search_query .= " AND ";
          $search_query .= " sex='$by_sex'";
          $isfirst=1;
        }
        if($by_group !="") {
            if($isfirst!=0)
            $search_query .= " AND ";
          $search_query .= " blood_group='$by_group'";
          $isfirst=1;
        }
        if($by_level !="") {
            if($isfirst!=0)
            $search_query .= " AND ";
          $search_query .= " e_level='$by_level'";
          $isfirst=1;
        }
        $result = mysql_query($search_query);

        return $result;
    }

Answer 6

In this where you don't use validation, it is recomended not to use whether Field is EMPTY or NOT. Try below code, Hope it will work

function search_donar($_POST) {

    $by_name = $_POST['by_name'];
    $by_sex = $_POST['by_sex'];
    $by_group = $_POST['by_group'];
    $by_level = $_POST['by_level'];

    $search_query = "SELECT * FROM donar WHERE name LIKE '%$by_name%' AND sex LIKE '%$by_sex%' AND blood_group LIKE '%$by_group%' AND  e_level LIKE '%$by_level%' ";

    $result = mysql_query($search_query);

    return $result;
}