将表从数据库从其他服务器上的MySQL Server复制到我的计算机

Question

I need to use a table of a database on a university server for test data for a project. I'm pretty new to databases and MySQL. My professor has send me username and password for the server. And an extra username&password for the MySQL server. It took me a while but in the end I was able to connect to the server over ssh and then managed to navigate to $cd / $cd usr/bin/MySQL then logged in and found the data/sentences in a table in one of the databases.

Now there is the question: How do I get the data on my computer? I thought about a python script. But I cannot write a script what is logging in on a different server and then navigates to the MySQL folder to log in there to copy somehow the sentences in the table to a txt file I can use?

Answer 1

You could use the mysqldump program (if it is available on your machine) to get a dump of the table you need.

if you would like to have the dump as SQL so you could insert it on your own database, you would call it with

mysqldump -u "USERNAME" -p "PASSWORD" -h "HOSTNAME" "DATABASE" "TABLE" > dump.sql

Omitting the password is strongly preferred so your password isn't saved in the shell history. You'll be prompted for it during execution.

and you would get a file with all SQL-Queries to recreate this table. You can as well export data from that table as CSV or XML, depending on the parameters used at call time.

if the database server would only be accessible from the second server you mentioned, but you can access this one via ssh, then you could try calling

ssh USER@HOST 'mysqldump --version'

which hopefully presents you with an output similar to this:

mysqldump  Ver xx.yy Distrib x.y.z, for debian-linux-gnu (x86_64)

if so, you would know there is this program installed and you could use the following line

ssh USER@HOST 'mysqldump -u "USERNAME" -p "PASSWORD" -h "HOSTNAME" "DATABASE" "TABLE"' | cat > dump.sql

which should present you the dump on your local machine.

Answer 2

You might not need to ssh into the remote server; depending how their server and database are set up you may be able to connect a mysql client on your local machine to the database server. While there are security advantages to limiting where connections are permitted from, accessing a database at localhost is actually just a special case.

You might not even need a python script. You can export directly from mysql to a text file, or your client may have a feature to copy data directly from the remote server into a local database.

I would guess that something like this would work for you, although getting the output into the format you want can be tricky:
mysql -h "host address" -u "username" -p -e "SELECT * FROM `table`" > localFile.txt

If you wanted to do it with a python script running on the server as you're describing, you'll want to use the ssh credentials to do FTP over SSH to get the files back and forth. Your FTP client will certainly support that.