A function for WordPress to check if a column exists in a database table or not. Returns true if a database table column exists. Otherwise returns false.

wordpress_table_column_exists.php

<?php

/**
 * Returns true if a database table column exists. Otherwise returns false.
 *
 * @link http://stackoverflow.com/a/5943905/2489248
 * @global wpdb $wpdb
 *
 * @param string $table_name Name of table we will check for column existence.
 * @param string $column_name Name of column we are checking for.
 *
 * @return boolean True if column exists. Else returns false.
 */
function mycode_table_column_exists( $table_name, $column_name ) {

	global $wpdb;

	$column = $wpdb->get_results( $wpdb->prepare(
		"SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = %s AND TABLE_NAME = %s AND COLUMN_NAME = %s ",
		DB_NAME, $table_name, $column_name
	) );

	if ( ! empty( $column ) ) {
		return true;
	}

	return false;
}