从命令行将 mysql 数据库转储到明文 (CSV) 备份

Question

I'd like to avoid mysqldump since that outputs in a form that is only convenient for mysql to read. CSV seems more universal (one file per table is fine). But if there are advantages to mysqldump, I'm all ears. Also, I'd like something I can run from the command line (linux). If that's a mysql script, pointers to how to make such a thing would be helpful.

Answer 1

If you can cope with table-at-a-time, and your data is not binary, use the -B option to the mysql command. With this option it'll generate TSV (tab separated) files which can import into Excel, etc, quite easily:

% echo 'SELECT * FROM table' | mysql -B -uxxx -pyyy database

Alternatively, if you've got direct access to the server's file system, use SELECT INTO OUTFILE which can generate real CSV files:

SELECT * INTO OUTFILE 'table.csv'
    FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
    LINES TERMINATED BY '\n'
FROM table

Answer 2

In MySQL itself, you can specify CSV output like:

SELECT order_id,product_name,qty
FROM orders
INTO OUTFILE '/tmp/orders.csv'
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n'

From http://www.tech-recipes.com/rx/1475/save-mysql-query-results-into-a-text-or-csv-file/

Answer 3

You can dump a whole database in one go with mysqldump's --tab option. You supply a directory path and it creates one .sql file with the CREATE TABLE DROP IF EXISTS syntax and a .txt file with the contents, tab separated. To create comma separated files you could use the following:

mysqldump --password  --fields-optionally-enclosed-by='"' --fields-terminated-by=',' --tab /tmp/path_to_dump/ database_name

That path needs to be writable by both the mysql user and the user running the command, so for simplicity I recommend chmod 777 /tmp/path_to_dump/ first.

Answer 4

select into outfile 选项对我不起作用，但下面通过 SED 管道制表符分隔文件的迂回方式做到了：

mysql -uusername -ppassword -e "SELECT * from tablename" dbname | sed 's/\t/","/g;s/^/"/;s/$/"/' > /path/to/file/filename.csv

Answer 5

Here is the simplest command for it

mysql -h<hostname> -u<username> -p<password> -e 'select * from databaseName.tableNaame' | sed  's/\t/,/g' > output.csv

If there is a comma in the column value then we can generate .tsv instead of .csv with the following command

mysql -h<hostname> -u<username> -p<password> -e 'select * from databaseName.tableNaame' > output.csv

Answer 6

You can use below script to get the output to csv files. One file per table with headers.

for tn in `mysql --batch --skip-page --skip-column-name --raw -uuser -ppassword -e"show tables from mydb"`
do 
mysql -uuser -ppassword mydb -B -e "select * from \`$tn\`;" | sed 's/\t/","/g;s/^/"/;s/$/"/;s/\n//g' > $tn.csv
done

user is your user name, password is the password if you don't want to keep typing the password for each table and mydb is the database name.

Explanation of the script: The first expression in sed, will replace the tabs with "," so you have fields enclosed in double quotes and separated by commas. The second one insert double quote in the beginning and the third one insert double quote at the end. And the final one takes care of the \\n.

Answer 7

If you really need a "Backup" then you also need database schema, like table definitions, view definitions, store procedures and so on. A backup of a database isn't just the data.

The value of the mysqldump format for backup is specifically that it is very EASY to use it to restore mysql databases. A backup that isn't easily restored is far less useful. If you are looking for a method to reliably backup mysql data to so you can restore to a mysql server then I think you should stick with the mysqldump tool.

Mysql is free and runs on many different platforms. Setting up a new mysql server that I can restore to is simple. I am not at all worried about not being able to setup mysql so I can do a restore.

I would be far more worried about a custom backup/restore based on a fragile format like csv/tsv failing. Are you sure that all your quotes, commas, or tabs that are in your data would get escaped correctly and then parsed correctly by your restore tool?

If you are looking for a method to extract the data then see several in the other answers.

Answer 8

Check out mk-parallel-dump which is part of the ever-useful maatkit suite of tools . This can dump comma-separated files with the --csv option.

This can do your whole db without specifying individual tables, and you can specify groups of tables in a backupset table.

Note that it also dumps table definitions, views and triggers into separate files. In addition providing a complete backup in a more universally accessible form, it also immediately restorable with mk-parallel-restore

Answer 9

If you want to dump the entire db as csv

#!/bin/bash

host=hostname
uname=username
pass=password

port=portnr
db=db_name
s3_url=s3://buckera/db_dump/



DATE=`date +%Y%m%d`
rm -rf $DATE

echo 'show tables' | mysql -B -h${host} -u${uname} -p${pass} -P${port} ${db} > tables.txt
awk 'NR>1' tables.txt > tables_new.txt

while IFS= read -r line
do
  mkdir -p $DATE/$line
  echo "select * from $line" | mysql -B -h"${host}" -u"${uname}" -p"${pass}" -P"${port}" "${db}" > $DATE/$line/dump.tsv
done < tables_new.txt

touch $DATE/$DATE.fin


rm -rf tables_new.txt tables.txt

Answer 10

Two line PowerShell answer:

# Store in variable
$Global:csv = (mysql -uroot -p -hlocalhost -Ddatabase_name -B -e "SELECT * FROM some_table") `
| ConvertFrom-Csv -Delimiter "`t"

# Out to csv
$Global:csv | Export-Csv "C:\temp\file.csv" -NoTypeInformation

Boom-bata-boom

-D = the name of your database

-e = query

-B = tab-delimited

Answer 11

There's a slightly simpler way to get all the tables into tab delimited fast:

#!/bin/bash
tablenames=$(mysql your_database -e "show tables;" -B |sed "1d")

IFS=$'\n'

tables=($tablenames)

for table in ${tables[@]}; do
        mysql your_database -e "select * from ${table}" -B > "${table}.tsv"
done

Answer 12

Here's a basic python script that does the work. You can also choose to export only the headers (column names) or headers & data both.

Just change the database credentials and run the script. It will output all the data to the output folder.

To run the script -

1. Run: pip install mysql-connector-python
2. Change database credentials in the "INPUT" section
3. Run: python filename.py

import mysql.connector
from pathlib import Path
import csv 

#========INPUT===========
databaseHost=""
databaseUsername=""
databasePassword=""
databaseName=""
outputDirectory="./WITH-DATA/"
exportTableData=True #MAKING THIS FIELD FALSE WILL STORE ONLY THE TABLE HEADERS (COLUMN NAMES) IN THE CSV FILE
#========INPUT END===========


Path(outputDirectory).mkdir(parents=True, exist_ok=True)

mydb = mysql.connector.connect(
  host=databaseHost,
  user=databaseUsername,
  password=databasePassword
)
mycursor = mydb.cursor()
mycursor.execute("USE "+databaseName)


mycursor.execute("SHOW TABLES")
tables = mycursor.fetchall()  

tableNames=[table[0] for table in tables]

print("================================")
print("Total number of tables: "+ str(len(tableNames)))
print(tableNames)
print("================================")

for tableName in tableNames:

    print("================================")
    print("Processing: "+ str(tableName))

    mydb = mysql.connector.connect(
        host=databaseHost,
        user=databaseUsername,
        password=databasePassword
    )
    mycursor = mydb.cursor()
    mycursor.execute("USE "+databaseName)

    if exportTableData:
        mycursor.execute("SELECT * FROM "+tableName)
    else:
        mycursor.execute("SELECT * FROM "+tableName+" LIMIT 1")

    print(mycursor.column_names)

    with open(outputDirectory+tableName+".csv", 'w', newline='') as csvfile: 
        csvwriter = csv.writer(csvfile) 

        csvwriter.writerow(mycursor.column_names) 

        if exportTableData:
            myresult = mycursor.fetchall()
            csvwriter.writerows(myresult)