直接将MySQL数据库压缩备份，会清空之前的数据mysqldump -–add-drop-table -hhostname -uusername -ppassword databasename | gzip > backupfile.sql.gzmysqldump --add-drop-table --single-transaction -hlocalhost -udiscuz -pdiscuzexp discuz | gzip > backupfile.sql.gz还原压缩的MySQL数据库gunzip < backupfile.sql.gz | mysql -uusername -ppassword databasenamegunzip < backupfile.sql.gz | mysql -udiscuz -pdiscuzexp discuz备份MySQL数据库为带删除表的格式，能够让该备份覆盖已有数据库而不需要手动删除原有数据库。mysqldump -–add-drop-table -uusername -ppassword databasename > backupfile.sqlmysqldump --add-drop-table --single-transaction -hlocalhost -udiscuz -pdiscuzexp discuz > backupfile.sql还原MySQL数据库的命令mysql -hhostname -uusername -ppassword databasename < backupfile.sqlmysql -hlocalhost -udiscuz -pdiscuzexp discuz < backupfile.sql