How do I update a substring of a column

[Tison]

I need to change the 5th character in a column.
I tried this statement but it does not work ;
update table_name
set substring(column_name,5,1) = "R"

 

[Guest_imported]

Hey,

You can use

update table_name
set column_name = substring(column_name,1,4)+'R'+substring(column_name,6,max_length)

Pravin