QProcess and mysql < backup.sql

[gboelter]

How can I get this working:



QString str = "mysql -uUser -pPassword -h172.16.1.110 < backup.sql";
myProcess->start( str );


I've tried it with a string and with a list, but it's both not working. I guess, my problem is the " < " as a part of my string. If the "<" is included, then mysql shows me the same like with "mysql --help", but no error message or something usefull else.

The same string at the commandline works well.

I'm using Qt 4.5.2 under Fedora 9.

Thanks in advance.

[wagmare]

as you are using Qt4.x version
QProcess::start() usally defined as

void QProcess::start ( const QString & program, const QStringList & arguments, OpenMode mode = ReadWrite )


QString proc = "mysql";
QStringList args;

args << " -uUser" <<"-pPassword" << "h172.16.1.110" << "<" << "ba...sql" ;

myprocess->start(proc, args);

[gboelter]

QString proc = "mysql";
QStringList args;
args << " -uUser" <<"-pPassword" << "h172.16.1.110" << "<" << "ba...sql" ;
myprocess->start(proc, args);


Thanks for your reply, but I have tried it before already in this way. Same result. Here is a part of the output I got:


"mysql Ver 14.12 Distrib 5.0.77, for redhat-linux-gnu (i386) using readline 5.1
Copyright (C) 2000-2008 MySQL AB
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL license
Usage: mysql [OPTIONS] [database]
-?, --help Display this help and exit.
-I, --help Synonym for -?
--auto-rehash Enable automatic rehashing. One doesn't need to use
'rehash' to get table and field completion, but startup
and reconnecting may take a longer time. Disable with
--disable-auto-rehash.
-A, --no-auto-rehash
No automatic rehashing. One has to use 'rehash' to get
table and field completion. This gives a quicker start of
mysql and disables rehashing on reconnect. WARNING:
options deprecated; use --disable-auto-rehash instead.
-B, --batch Don't use history file. Disable interactive behavior.
(Enables --silent)
--character-sets-dir=name


I can make a backup with:


QString backup = "mysqldump --database " + db
+ " --user=" + dbUser
+ " --password=" + dbPassword
+ " --host=" + dbHost
+ " --log-error backup.log"
+ " --verbose --opt"
+ " --result-file " + fileName;
myProcess->start( backup );


This works fine for me, but at the moment I add "<" to a commandline, then it's not working anymore.

[yogeshgokul]

This works fine for me, but at the moment I add "<" to a commandline, then it's not working anymore.
Whats this for pipe lining or something ?

[gboelter]

Whats this for pipe lining or something ?

I don't know. It's a part of a standard command for mysql.

On a command line "mysql -uMyUser -pMyPassword < backup.sql" works fine for me, but the same line with QProgress don't work.

[yogeshgokul]

Read this (http://www.devshed.com/c/a/MySQL/Backing-up-and-restoring-your-MySQL-Database/).
Please try to use reverse sign.
">" instead of "<".

If it works ! fine.
Otherwise I suggest, do not use any one. Because this sign is just passing the backup file name to MySql command. And your code is working so you don't need any sign.

[lyuts]

1) Are you sure myProcess knows where backup.sql is located?
2) What if you pass "-e backup.sql" instead of passing backup.sql through redirection?

[gboelter]

1) Are you sure myProcess knows where backup.sql is located?
2) What if you pass "-e backup.sql" instead of passing backup.sql through redirection?

Thank you guys,

the problem is really the "<" sign, no idea why ... :confused:

With "-e backup.sql" it don't work too, so I have changed the way to do backup & restore to this now:



myProcess->start( curDir+"/restore", QStringList() << db << dbUser << dbPassword << dbHost << fileName );

where 'restore' is a simple batch file.

I guess, it's even the better approach because it's easy to change, if somebody has a different SQL-database.

Thanks again and have a nice day.

[lyuts]

What if you specify the full path to backup.sql?

[gboelter]

What if you specify the full path to backup.sql?

The same, not working ...

And if I make a mistake in writing, 'back-up.sql' for example, then QProcess tells me 'file not found'. That means for me, that the file can not be the problem.

[kkk777kkk]

yes the sign < and > don't work if you use qprocess
but i find how to use this:

void QProcess::setStandardInputFile ( const QString & fileName )
void QProcess::setStandardOutputFile ( const QString & fileName, OpenMode mode = Truncate )

this works fine :p

[Lesiok]

"< backup.sql" this is a parameter for Command Interpreter not for mysql. It redirects stdio to file backup.sql. mysql has nothing to this.

[endof]

How can I get this working:



QString str = "mysql -uUser -pPassword -h172.16.1.110 < backup.sql";
myProcess->start( str );


I've tried it with a string and with a list, but it's both not working. I guess, my problem is the " < " as a part of my string. If the "<" is included, then mysql shows me the same like with "mysql --help", but no error message or something usefull else.

The same string at the commandline works well.

I'm using Qt 4.5.2 under Fedora 9.

Thanks in advance.


use bash -c " " bash command


QString str = "bash -c \"mysql -uUser -pPassword -h172.16.1.110 < backup.sql\" ";
myProcess->start( str );