i m just a beginner of mysql
i want to know the command of
1- backup of database
2-restore database
3- merge two database and result will be one database...
if any one want to share their knowledge with me then i will be highly obliged...
Thank in advance

There are tools like phpMyAdmin which helps by providing a GUI interface for executing the various commands that you are looking for. However, if you want to execute the commands yourself from the command line:

1. mysqldump - for taking backups
2. The result of the mysqldump command is a file containing SQL statements to both recreate the tables with permissions as well as insert statements to populate the tables.
3. To merge database contents you simply apply the SQL file above into the database you wish to merge the contents with.