Msg 4421, Level 16, State 1, Line 1
Derived table ‘%.*ls’ is not updatable because a column of the derived table is derived or constant.
This error message appears when you try to update a column of a derived table that is either derived or constant.
The T-SQL statement can be parsed, but causes the error at runtime.
Errors of the Severity Level 16 are generated by the user and can be fixed by the SQL Server user. The statement cannot be executed this way. You cannot update a derived or constant column of a derived table.
All versions of SQL Server.
c1 = 2
1 AS c1) t
In the above example we try to update the column c1 of the derived table t. Because c1 is a constant, the error is raised.