How can I move the value of all cells from column A to column B?

Question

PostgreSQL

Hello, I use PgAdmin 3, I also have access to the console, I also didn’t find anything in the PgAdmin interface, of course you can copy and paste one by one value, but I have 1055 of them. mirror replace table B with values ​​from column A. Mb where there is an option in PgAdmin3 or SQL query.

Answer 1

UPDATE table SET column1=column2

Answer 2

insert into dest_table_name (column_name)
    select column_name from src_table_name;