how to copy a column in sql code example

Example 1: copy all values of a column to another column in sql in same table

UPDATE table SET columnB = columnA;

Example 2: how to copy data in sql

Let’s assume that, we have our employee table.
We have to copy this data
into another table. For this purpose,
we can use the INSERT INTO SELECT
operator. Before we go ahead and do that,
we would have to create another
table that would have the same structure
as the given table.
• First create the second table with
the same table structure with copied one.
• Then use the syntax:
Let’s say employee_duplicate is New table
employee is First table that we want to copy it into new table

INSERT INTO employee_duplicate SELECT * FROM employee;