How to get all columns' names for all the tables in MySQL?

To list all the fields from a table in MySQL:

select * 
  from information_schema.columns 
 where table_schema = 'your_DB_name' 
   and table_name = 'Your_tablename'

select column_name from information_schema.columns
where table_schema = 'your_db'
order by table_name,ordinal_position

it is better that you use the following query to get all column names easily

Show columns from tablename

SELECT * FROM information_schema.columns
WHERE table_schema = DATABASE()
ORDER BY table_name, ordinal_position

Since I don't have enough rep to comment, here's a minor improvement (in my view) over nick rulez's excellent answer: replacing WHERE table_schema = 'your_db' with WHERE table_schema = DATABASE().