Secondary Navigation. 1  Active Duty Dental Care. 2  Guard/Reserve Dental Care. 3  TRICARE Dental Program. 4  TRICARE Retiree Dental Program. 5  Enrolling in the TRICARE Retiree Dental Program. Costs. 6  Dental Benefits for Survivors. 7  Find a Dentist.
â¢ Although char and varchar are character data fields, char is a fixed length data field and varchar is a variable size data field. â¢ Char can store only fixed size non-Unicode string characters, but varchar can store variable sizes of strings.
Another difference is length. Both nchar and nvarchar can be up to 4,000 characters long. And char and varchar can be up to 8000 characters long. But for SQL Server you can also use a [n]varchar(max) which can handle up to 2,147,483,648 characters.