Mysql - 如果找不到特定记录，则抓取默认记录

Question

Using MySQL and php how would I, in a single query, grab all results matching a certain query but if no results found it then finds all the default results? For example I have this query:

SELECT * FROM table1 WHERE typeid = 5

If no results are found from the query below then I want to find all results from table1 with the typeid of 1:

SELECT * FROM table1 WHERE typeid = 1

How can I do that in a single query? If I try the following query I get both 5 and 1:

SELECT * FROM table1 WHERE typeid = 5 OR typeid = 1

All I want to to is query table1 for all records assigned with typeid of 5, if no results found then get all results assigned to typeid = 1 in a single query. How can I do that? Or do I have to have 2 queries?

EDIT

I need this for multiple records returned, not a single record.

Answer 1

SELECT *
FROM   table1
WHERE  typeid = IF((SELECT COUNT(*) FROM table1 WHERE typeid = 5), 1, 5);