Now I need to select from remote database and insert the result into local database. I can do it in two steps, select first, and then insert second. But it seems to be slow for large set of records.

I would like to use subquery, something like

//get the data from remotedatabase
$sql_select_records_from_remotedatabse=”SELECT field_1, field_2 FROM remotedatabase.table1″;

//insert into localsdatabase using subquery

$sql_insert_records_to_localdatabase=”INSERT INTO table_a (field_a, field_b) $sql_select_records_from_remotedatabse”;

some threads suggest to make it work, I need to use sp_addlinkedserver.

solution for remote server
Submitted by Anonymous (not verified) on Tue, 06/02/2009 – 11:56.

1. first add the server to your local sql server (from where you want to run the query)

exec sp_addlinkedserver [192.168.1.130]

2. now run the query as

select * from [192.168.1.130].[pubs].[dbo].[authors]

Did you run into the same situation, if so, what is your solution?

Thanks!

Thanks Robert. I got it works now!

A few points to answer my own questions:

1) >> logfile is needed. (as robert’s post)
2) I use regular mysql_connect and set up the host to be “127.0.0.1:3307″, so I get the localport too, but somehow “localhost:3307″ is not working, it has to be “127.0.0.1:3307″.
3) and if I run web page due to user is “apache”, I will need to set key pairs for user apache. But I will run my php from shell command, and the “user” will be just my user account.

Thanks again!

ssh -f -L 3307:127.0.0.1:3306 user@remotehost sleep 60
mysql -u mysqluser -p -h 127.0.0.1 -P 3307

Works fine! I think that I am in the right direction.

But I wrote test.php with following php codes:

shell_exec(”ssh -f -L 3307:127.0.0.1:3306 user@remotehost sleep 60”);
$db = mysqli_connect(’127.0.0.1′, ’sqluser’, ’sqlpassword’, ‘sqldatabase’, 3307);

I then run command line
php test.php

It gave me Error: Can’t connect to MySQL server on ‘127.0.0.1′ (111)

So I change test.php to the following line:

shell_exec(’ssh -f -L 3307:127.0.0.1:3306 user@remotehost sleep 60′);
shell_exec(‘mysql -u mysqluser -p -h 127.0.0.1 -P 3307′);

Run command line
php test.php

I would be prompted for password, but after I keyed in password, I still got Error: Can’t connect to MySQL server on ‘127.0.0.1′ (111)

Any one has any advices, some set ups I would need? Still thanks for your help, at least I am close to get it working.

So use php to connect mysql through ssh that is the only way, right?

thanks for this instruction! Due to I will be doing many of same kind works, get data from remote mysql, like you did, a few quick questions.

1) so you run this php script through command line not web page to get the remote database data, due to it is command line, there are several types scripts you can use, why use php, any other programming scripts will do the command line mysql job better? php is on my top to use list too, only because it is the script I am more familiar with than other scripts.

2) if you already have mysql access through ssh to remote host, why not just run one mysqldump command to get the mysql data from remote host? will that be simpler and safer? (or usually you would not be granted the ‘lock” rights?

3) about the ssh sleep 60, when the ssh tunnel will be closed, after the php script executed. Then if I am running second php script right after the first, will that port 3307 be already released after first page finished, or will the 3307 still in use, and my second php page will get error?

Thanks again!

But I didn’t see the following line
PubkeyAuthentication yes

Will this line be required “PubkeyAuthentication yes” for the passwordless to work.

Thanks!

One more question:

I have set up my account keys pair and paste my public key to one remote account, and the passwordless authentication is working fine.

But on another remote account, I did the same thing, but I cannot get the passwordless access to that account. I double checked the authorized_keys file, ssh folder and their permissions. They are all set up right. But somehow it works on one machine but not on another.

Both remote accounts have open ssh, and I can generate keys at both remote accounts.

You have to access many remote accounts from your clients. Any issues that you think may stop me to passwordless access to that remote account (it always ask for the password.)

It should output the linux user that is actually executing commands when using the shell_exec() function. Configure passwordless authentication for this user. Also, as a general rule, I would make sure everything is working from the command line first before doing it from PHP.

Good luck.