MySQL JOIN查询帮助：对于最左侧表中的每一行，只返回最右侧表中的一行

I have two tables. I want to join them in a way that only one record in the right table is returned for each record in the left most table. I've included an example below. I'd like to avoid subqueries and temporary tables as the actual data is about 4M rows. I also don't care which record in the rightmost table is matched, as long as one or none is matched. Thanks!I have two tables. I want to join them in a way