How to replace specific values in a oracle database column?

Question

I am looking to replace values in a particular column. For example the following column values

column name
----------
Test1
Test2
Test3
Test12

Answer 1

In Oracle, there is the concept of schema name, so try using this

update schemname.tablename t
set t.columnname = replace(t.columnname, t.oldvalue, t.newvalue);