Append text to column data based on the column in PostgreSQL

Question

I would like to append some text to every cell in each column of my table to act as a symbol for that particular column. For example say my table is as follows (all fields are t

Answer 1

The accepted answer is not handle null value and blank space. So I gave this answer. If it help someone, it will be my pleasure.

update "public"."mytable" set 
"name"= case when "name" is null or trim("name")='' then null else 'a' || "name" end,
"age"= case when "age" is null or trim("age")='' then null else 'b' || "age" end,
"location"= case when "location" is null or trim("location")='' then null else 'c' || "location" end;