SQL

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

UPDATE table SET columnB = columnA;

copy one column data to another in sql

#copy one column data to another in sql

Syntax 
UPDATE `table` SET new_column_name = old_column_name;

Example
UPDATE `toppers` SET tpicx = tpic;

copy data from one table column to another table column in sql

#to copy or update a table column from another table column 
UPDATE table_name1 
    SET column1 = (
        SELECT column2
        FROM table_name2
        WHERE table_name1.id = table_name2.id
    );