Wordpress Plugin development for Contact Form - php

Question

I am developing a simple WordPress plugin for contact form. But I don't know how to save the information in database? Could you gives some references?

Answer 1

The answer by Haninder has a great start but doesn't store the data in a database as per the OP.
This is where it starts getting tricky, as there are many options.
You can easily store the data in various places, but none are semantically correct, or maintainable over a long period of time.
In a single option in the options table
function save_request( $data ){
$opts = get_option( 'contact_requests' );
if( ! $opts || ! is_array( $opts ) ){
$opts = array();
}
$opts[] = $data;
update_option( 'contact_requests', $opts );
}
This would mean a slow request to save and defeats the point of a database in the first place, after several hundred contact requests, also diaplying and sorting the data would get tricky.
The best way would really to have a custom database table but there is a lot to consider when going down this path.
https://code.tutsplus.com/tutorials/custom-database-tables-creating-the-table--wp-28124
Custom Post Type
This is how I would approach this problem.
perhaps you could create a custom post type, say "contact_requests" and create a post with some post meta to represent a contact request.
This way you already get a neat list in admin, and can sort and access the data quickly and easily as required. This would be stable and fast through hundreds of thousands of entries.
function save_request( $data ){
$content = '';
foreach( $data as $key => $name ){
$content .= sprintf( '%s - %s' . PHP_EOL, $key, $name );
}
$post_data = array(
'post_title' => 'Contact Request ' . esc_html( $data['name'] ),
'post_content' => $content,
'post_type' => 'contact_requests'
);
$post_id = wp_insert_post( $post_data );
//Add Post Meta Here
add_post_meta( $post_id, 'contact_name', esc_html( $data['name'] ) );
add_post_meta( $post_id, 'contact_email', esc_html( $data['email'] ) );
add_post_meta( $post_id, 'contact_message', esc_html( $data['message'] ) );
return $post_id;
}