php - PHP MySQL条件语法里面查询

$category = get_option('category');

// checks to see if subcategory is enabled in the option page
if ( get_option('enable_subcategory') == 'y' ):

  $subcategory = get_option('subcategory');

endif;

$qry = mysql_query("SELECT car,number FROM ".$table."
                    WHERE category = '$category' AND subcategory = '$subcategory'
                    ORDER BY RAND() LIMIT 20");

如果未启用子类别选项，我如何编写$ query以便“ AND子类别='$ subcategory'”消失？

最佳答案

添加了$subSql var：

<?

  $category = get_option('category');

  if ( get_option('enable_subcategory') == 'y' ):   // checks to see if subcategory is enabled in the option page

  $subcategory = get_option('subcategory');
  $subSql = "AND subcategory = '$subcategory'";

  endif;

  $qry = mysql_query("SELECT car,number FROM ".$table." WHERE category = '$category' $subSql ORDER BY RAND() LIMIT 20");

?>