如果存在多个默认值，请避免使用默认值，或者选择Mysql中的现有单个值

Question

In my website, I have a product image display region. When a user click on a product, it will redirect to the image display page. I had set a default image. Which will display when user see the product. But when the user go to the product image page, I don't want to show the default image, if there exist more than one image. But I need to show the default image if there exist only one image in the database. Currently I am doing this with two queries. Is there any way to do this with a single query?

I need something like

select image from table where if exists more than 1 then select 'non-featured' else select 'featured'

Please help

Answer 1

You can work yourself around by using the group function max(). This function should always return you just 1 image, if it can find it. Otherwise it will return null. Then use the function ifnull() to get your default image.

select ifnull(max(image),'default_image.jpg') from table