Is there a way to update multiple columns in SQL server the same way an insert statement is used?
Update table1 set (a,b,c,d,e,f,g,h,i,j,k)=
from table2 t2
update table set a=t2.a,b=t2.b etc
The "tiresome way" is standard SQL and how mainstream RDBMS do it.
With a 100+ columns, you mostly likely have a design problem... also, there are mitigating methods in client tools (eg generation UPDATE statements) or by using ORMs