Solving query problem: How to get all the results from the Customers table and replace the null values ​​in the Status and Fax columns with empty strings?

Question

I am very confused about this question. The problem is that I know I can use the COALESCE function, but how? Because there are two columns here, State and Fax.

Answer 1

You can use if null

select id,ifnull(state, '') as state ,ifnull(fax, '') as fax from customer