sysname and longsysname are user-defined datatypes used in the system tables. sysname is defined as:
varchar(30) "NOT NULL"
longsysname is defined as:
varchar(255) "NOT NULL"
You can declare a column, parameter, or variable to be of type sysname or longsysname. Alternately, you can also create a user-defined datatype with a base type of sysname or longsysname.
You can then use this user-defined datatype to create columns. See “Creating user-defined datatypes”.
