Using searchbox to query same data as dropdown - php

Question

I am currently developing an application which allows the user to pick an option from a dropdown, and list table data based on this option, and done so dynamically. I was pondering the thought of a search bar which allows the user to search for a country name (within a continent) and list said country name upon searching. The part which confuses me is can I make it so that the user can pick a continent from the dropdown, and input a country name into the search bar then click the same button and receive the listing?
I understand the importance of picking relevant code however I think it would be important for the reader to see both my home page, and action page to understand what I am trying to achieve.
Here is the index code:
require_once('repeat_code.php');
$db = dbConn();
//Make an SQL statement
$sqlContinents = "SELECT DISTINCT ID as contID, Name as contName from w_Continent order by contName;";
//Execute SQL statement
$stmt = $db->query($sqlContinents);
//Start a form
echo "<form action='listCont.php' method='get'>\n";
//Start a select box
echo "<select name='contID'>\n";
//Loop through all continents
while ($continent = $stmt->fetchObject()) {
//Display each one as an option in the dropdown
echo "\t\t<option value='{$continent->contID}'> {$continent->contName} </option>\n";
}//end loop
// end select box
echo "</select>\n";
// display submit button
echo "<input type='submit' value='Find Country' />\n";
// end form
echo "</form>\n";
Here is the action page:
if(!empty($contID)) {
//Connect to the database
require_once('repeat_code.php');
$db = dbConn();
//Create SQL statement using ID
$sqlCountries = "SELECT w_Country.Name, w_Continent.Name as 'contName', w_Country.Region as 'regionname', w_Country.HeadOfState, w_Country.Capital
FROM w_Continent JOIN w_Country on w_Continent.ID = w_Country.Continent
WHERE w_Continent.ID = '$contID'";
//Execute statement to get a record set back
$stmt = $db->query($sqlCountries);
// Start a table
echo "<table border='1'>\n";
// Start a header row
echo "<tr><th>Country</th><th>Continent</th>\n";
//Loop through the record set
while ($continent = $stmt->fetchObject()) {
//Display each student in a row
echo "\t<tr><td>{$continent->Name}</td><td>$continent->contName</td>\n";
}//End loop
//end the table
echo "</table>";
Any help is appreciated.

Answer 1

Create a drop down and input box in a single line.
Drop Down Contain the continent and input box is empty.
In database create 2 tables in following format.
Continent Table
id | Continent_name
Countries Table
id | country_name | continent_id
Now run query in first table and display all the continent in drop down.
now when user select the continent name from the drop down and also write country name in the search box, then you have to query like this.
<form method="post">
<input type="hidden" name="command" value="search">
<select name="select_box">
<option value ="1">Asia</option>
<option value ="2">Africa</option>
</select>
<input type ="text" name="search_box" placeholder="Type Country">
</form>
Now Run PHP code like below.
if($_REQUEST['command']=='search'){
$continent_id = $_REQUEST['select_box']; //suppose user select asia
$country_name = $_REQUEST['search_box']; // suppose user type "Pakistan"
//now execute below query in countries table.
$query ="select * from countries where continent_id='$continent_id' and country_name like '%$country_name%'";
}