Update values from one column in same table to another in SQL Server

Question

I\'m trying to overwrite values that are found in TYPE1 with values that are found in TYPE2.

I wrote this SQL to try it out, but for some reason it isn\'t updating:<

Answer 1

UPDATE TABLE_NAME SET COLUMN_A = COLUMN_B;

Much easier. At least on Oracle SQL, i don't know if this works on other dialects as well.