wordpress query to save in database

1<?php
2    if (!empty($_POST)) {
3        global $wpdb;
4        $table = 'contact_form';
5        $data = array(
6            'names' => $_POST['yourname'],
7            'emails'    => $_POST['customer_email'],
8            'gender' => $_POST['customer_gender'],
9            'age' => $_POST['customer_age']
10        );
11        //echo "<pre>"; print_r($data);
12
13        $success=$wpdb->insert( $table, $data );
14        if($success){
15            echo 'data has been save' ; 
16        }
17    } else {
18    		echo "data not save";
19    	}
20        ?>
21        <div class="container">
22        	<div class="row ">
23        		<div class="col-md-12 pb-5">
24			        <form method="post">
25			            Your name:<input type="text" name="yourname" id="yourname">
26			            Your Email:<input type="text" id="customer_email" name="customer_email"/><br>
27							Gender:<input type="radio" name="customer_gender" value="male">Male
28								   <input type="radio" name="customer_gender" value="female">Female<br>
29						    Your Age:<input type="text" name="customer_age" id="customer_age"><br>
30						    <input type="submit" name="submit" value="Submit">
31			        </form>
32		        </div>
33	        </div>
34	    </div>
35        

1<?php
2// 2nd Method - Utilizing the $GLOBALS superglobal. Does not require global keyword ( but may not be best practice )
3$results = $GLOBALS['wpdb']->get_results( "SELECT * FROM {$wpdb->prefix}options WHERE option_id = 1", OBJECT );
4

1global $wpdb;
2
3$wpdb->insert(
4'table',
5array( 'value' => $value ),
6array( '%s' ),
7);
8
9   
10
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12