The basic commands for backing up the database of mysqldump are: mysqldump -u username -p database name > backup file.sql; 1. You can use the --databases parameter to back up multiple databases at once, such as: mysqldump -u user-p--databases db1 db2>multi-store backup.sql; 2. You can use the --all-databases parameter to back up all databases; 3. To save space, you can combine gzip compression, such as: mysqldump -u user-p database|gzip>backup.sql.gz; 4. Automatic backup can be implemented by writing scripts and cooperating with cron timing execution.
Directly answer the title question: Backing up the MySQL database with mysqldump is a very basic and practical method in operation and maintenance. The key is to master several common parameters and operation processes.
How to write basic commands?
The easiest way to backup is to use mysqldump plus the database name and output it to a .sql file. for example:
mysqldump -u Username -p Database name > Backup file.sql
After executing this command, you will prompt for a password. After the input is correct, you will start to export. This method is suitable for daily backups of a single database. Pay attention to replacing the user name, database name and file name.
If you have set the default user or operate locally, sometimes -u and -p can be omitted, but for clarity and security, it is recommended to write it clearly.
How to back up multiple databases at once?
If you want to back up multiple databases at the same time, you can add multiple database names after the command, or add the --databases parameter. In this way, the generated SQL file will automatically include CREATE DATABASE IF NOT EXISTS statement, which is more convenient when recovering.
The command is probably like this:
mysqldump -u Username -p --databases db1 db2 db3 > Multi-store backup.sql
This method is suitable for situations where you have several associated databases and want to save them together.
If you want to back up all databases under the entire MySQL instance, you can use --all-databases :
mysqldump -u Username -p --all-databases > Full library backup.sql
How to make backups faster and more space-saving?
By default, mysqldump exports plain text SQL files, which are relatively large in size. If you want to save space, you can directly add the compression command and compress while exporting.
For example, use gzip compression:
mysqldump -u Username -p Database name | gzip > Backup file.sql.gz
The .gz file generated in this way is usually only 10%~30% of the original file, which is especially suitable for regular backup or remote transmission.
In addition, if you only want to backup the structure but not back up the data, you can add --no-data ; if you only backup the data but not back up the structure, use --no-create-info . These two options are useful when doing a difference check or a specific recovery.
How to do automatic backup?
If you don't want to execute commands manually every time, you can write the above statement into a script and execute it regularly with cron .
For example, write a shell script first:
#!/bin/bash BACKUP_DIR="/backup/mysql" DATE=$(date %Y%m%d) mysqldump -u root -p Password database name | gzip > $BACKUP_DIR/db_$DATE.sql.gz
Then set permissions and join cron:
- chmod x script name.sh
- crontab -e
- Add a line like:
0 2 * * * /path/to/腳本名.sh
This will automatically backup once every day at 2 a.m. Remember to replace the path and account information with your own.
Basically, these are not complicated but easily overlooked include: permission issues, insufficient disk space, compressed file reading methods, etc. In actual use, parameters can be flexibly combined as needed.
The above is the detailed content of Backing Up a MySQL Database Using mysqldump. For more information, please follow other related articles on the PHP Chinese website!
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