how to export or take backup mysql database from command promprt in windows

find your mysql location where you installed

C:\Program Files\MySQL\MySQL Server 5.0>

then move to bin folder

C:\Program Files\MySQL\MySQL Server 5.0\bin>

then use this comand

mysql --user=root -proot testdb > export.sql

this will create export.sql file in the bin folder.

if you want to save backup file in the specific path then you give like that

mysql --user=root -proot testdb > d:\db_backup\export.sql