当连接表where子句上没有条目时，SQL Server返回结果行

I've got an issue where I'm trying to pull timesheets from periods for a person. If they have an entry, I get a row with their name and timesheet status. But if they have not submitted either of the two timesheets in a period, they don't show up at all in the query (meaning they'd be missed when someone goes to followup with them).I've got an issue where I'm trying to pull time