Select FolderName
	,COALESCE(Permission,'None') Permission
	--,IsNull(Permission,'None') Permission --Alternate to COALESCE
From Folder f
	LEFT OUTER JOIN [Permissions] p 
		on f.FolderId=p.FolderId

Create Table #folder (FolderId int, FolderName varchar(100))
Create Table #Permissions (FolderId int, FolderName varchar(100),Permission varchar(100))


Insert into #Folder
Select 1 ,'Folder1'
Union Select 2 ,'Folder2'
Union Select 3 ,'Folder3'
Union Select 4 ,'Folder4'
Union Select 5 ,'Folder5'
Union Select 6 ,'Folder6'
Union Select 7 ,'Folder7'

insert into #Permissions
Select 1,'Folder1' ,'Read'
Union Select 2 ,'Folder2' ,'Admin'
Union Select 3 ,'Folder3' ,'None'
Union Select 4 ,'Folder4' ,'admin'

Select f.FolderName
	,COALESCE(Permission,'None') Permission
	--,IsNull(Permission,'None') Permission --Alternate to COALESCE
From #Folder f
	LEFT OUTER JOIN #Permissions p 
		on f.FolderId=p.FolderId