Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/wordpress-seo/src/helpers/wpdb-helper.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Yoast\WP\SEO\Helpers;
+
+use wpdb;
+
+/**
+ * A helper object for the wpdb.
+ */
+class Wpdb_Helper {
+
+	/**
+	 * The WordPress database instance.
+	 *
+	 * @var wpdb
+	 */
+	private $wpdb;
+
+	/**
+	 * Constructs a Wpdb_Helper instance.
+	 *
+	 * @param wpdb $wpdb The WordPress database instance.
+	 */
+	public function __construct( wpdb $wpdb ) {
+		$this->wpdb = $wpdb;
+	}
+
+	/**
+	 * Check if table exists.
+	 *
+	 * @param string $table The table to be checked.
+	 *
+	 * @return bool Whether the table exists.
+	 */
+	public function table_exists( $table ) {
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Reason: There is no unescaped user input.
+		$table_exists = $this->wpdb->get_var( "SHOW TABLES LIKE '{$table}'" );
+		if ( \is_wp_error( $table_exists ) || \is_null( $table_exists ) ) {
+			return false;
+		}
+
+		return true;
+	}
+}