How to check sql database table field null or 0 and if so replace it with other column

Question

I have a SQL query; I want to check two columns in query to check if they are null or 0; if so, then I want to replace then with other column's values.

Here is my query: I have used coalesce to check if it is null but how can I check for 0 and also how can I replace the columns with other values?

SELECT 
    t.Name
    ,t.Code
    ,c.Description
    ,st.APriceOld
    ,st.CPriceOld
    ,st.APriceNew
    ,st.CPriceNew
    COALESCE(st.APriceOld,st.APriceNew),
    COALESCE(st.CPriceOld,st.CPriceNew) 
FROM
    Table t
INNER JOIN
    STCP st ON st.PriceId = t.PriceId

Can anybody help me to get the expected result?

So if old price values are 0 or null, then they should be replaced with new price values

Answer 1

One more approach - use nullif() function:

SELECT 
    t.Name
    ,t.Code
    ,c.Description
    ,st.APriceOld
    ,st.CPriceOld
    ,st.APriceNew
    ,st.CPriceNew
    COALESCE(NULLIF(st.APriceOld, 0), st.APriceNew),
    COALESCE(NULLIF(st.CPriceOld, 0), st.CPriceNew) 
FROM
    Table t
INNER JOIN
    STCP st ON st.PriceId = t.PriceId