save_search_wordpress.php

<?php

function dcms_count_text_search( $query_object ) {
	if( $query_object->is_search() ) {
		global $wpdb;

		$table = $wpdb->prefix . 'text_search'; //Nombre de la tabla
		$col_search = 'search'; //unique
		$col_count = 'count';

		$search_text = $query_object->query['s'];

		// Buscamos la cantidad de repeticiones si el texto existe
		$sql = $wpdb->prepare("SELECT `$col_count` FROM `$table` WHERE `$col_search` = '%s'", $search_text);
		$count = $wpdb->get_var($sql) ?? 0;

		// Insertamos o actualizamos
		$wpdb->replace( $table, [$col_search => $search_text, $col_count => $count + 1], ['%s', '%d'] );
    }
}

add_action( 'parse_query', 'dcms_count_text_search' );


// # Base table: 
// CREATE TABLE wp_text_search (
// 	search VARCHAR(200) NOT NULL UNIQUE,
// 	count INT DEFAULT 0
// );