SQL self join to eradicate duplicate keys

Question

I have a table with below columns:

Column1	Column2	Column3
A	Hello	NULL
A	NULL	WORLD

I want the above table to transform like below:

Column1	Column2	Column3
A	Hello	WORLD

I'm using Snowflake DataWarehouse. Need help in the above transformation using SQL

Answer 1

select column1,
       max(column2) as column2,
       max(column3) as column3
  from your_table
 group by column1;