I'm trying to follow the instructions here https://github.com/go-sql-driver/mysql#installation and http://go-database-sql.org/accessing.html to create a sql.db.
The first line of my code has this
db, err := sql.Open("mysql", "username#localhost/my_db")
When I ran the program on the terminal, I got this:
Default addr for network ''localhost'' unknown
Why is this? When I checked the user and host to mysql it states 'username' and 'localhost'. I followed the parameters like this:
[username[:password]#][protocol[(address)]]/dbname[?param1=value1&...¶mN=valueN]
You might want to specify the protocol (like 'tcp'), instead of localhost directly.
See those examples:
user:password#tcp(localhost:5555)/dbname
In your case:
username#tcp(localhost)/my_db
Note, if you use the default protocol (tcp) and host (localhost:3306), this could be rewritten as
user:password#/dbname
Lakshminarayanan Guptha adds in the comments:
In my case - user:password#tcp/dbname worked
I had the same problem and the most voted answer couldn't help me. What saved me was putting (host:port) inside quotation --> "(host:port)"
I had faced a similar issue as I was running Docker containers on my Linux VM. In my application (server.go) I changed the localhost value to use the IP of my virtual machine and then build and ran the container successfully.
mysql container (3307) <--> [(application mysql:<vm ip>:3307) container](expose 3000) <--> world
Related
I'm working on a Perl6 project, but having difficulty connecting to MySQL. Even when using the DBIish (or perl6.org tutorial) example code, the connection fails. Any suggestions or advice is appreciated! User credentials have been confirmed accurate too.
I'm running this on Windows 10 with MySQL Server 8.0 and standard Perl6 with Rakudo Star. I have tried modifying the connection string in numerous ways like :$password :password<> :password() etc. but can't get a connection established. Also should note that I have the ODBC, C, C++, and.Net connectors installed.
#!/usr/bin/perl6
use v6.c;
use lib 'lib';
use DBIish;
use Register::User;
# Windows support
%*ENV<DBIISH_MYSQL_LIB> = "C:/Program Files/MySQL/MySQL Server 8.0/liblibmysql.dll"
if $*DISTRO.is-win;
my $dbh = DBIish.connect('mysql', :host<localhost>, :port(3306), :database<dbNameHere>, :user<usernameHere>, :password<pwdIsHere>) or die "couldn't connect to database";
my $sth = $dbh.prepare(q:to/STATEMENT/);
SELECT *
FROM users
STATEMENT
$sth.execute();
my #rows = $sth.allrows();
for #rows { .print }
say #rows.elems;
$sth.finish;
$dbh.dispose;
This should be connecting to the DB. Then the app runs a query, followed by printing out each resulting row. What actually happens is the application hits the 'die' message every time.
This is more of a work around, but being unable to use use a DB is crippling. So even when trying to use the NativeLibs I couldn't get a connection via DBIish. Instead I have opted to using DB::MySQL which is proving to be quite helpful. With a few lines of code this module has your DB needs covered:
use DB::MySQL;
my $mysql = DB::MySQL.new(:database<databaseName>, :user<userName>, :password<passwordHere>);
my #users = $mysql.query('select * from users').arrays;
for #users { say "user #$_[0]: $_[1] $_[2]"; }
#Results would be:
#user #1: FirstName LastName
#user #2: FirstName LastName
#etc...
This will print out a line for each user formatted as shown above. It's not as familiar as DBIish, but this module gets the job done as needed. There's plenty more you can do with it to, so I highly recommend reading the docs.
According to this github DBIish issue 127
The environmental variable DBIISH_MYSQL_LIB was removed. I don't know if anyone brought it back.
However if you add the library's path, and the file is named mysql.dll, it will work. Not a good result for the scientific method.
So more testing is needed - and perhaps
C:\Program Files\MySQL\MySQL Server 8.0\lib>mklink mysql.dll .\libmysql.dll
Oviously you can create your own lib directory and add that to your path and then add this symlink to that directory.
Hope this helps. I've spent hours..
EDIT: Still spending time - accounting later.
Something very transitory is going on. I reset the machine (perhaps always do this from now on), and still got the missing mysql.dll errors. Tried going into the MySQL lib directory to execute raku from there.. worked. changed directories.. didn't work.
Launched administrator cmd - from home directory, tried the raku command. Worked. Ok - not good, but perhaps consistent. Launched non admin cmd, tried it from the MySQL lib directory, worked. And just for giggles, tried it outside of that directory.. worked.
Now I can't get it not to work. Will explore NativeLibs::Searcher as Valle Lukas suggested!
Maybe the example in the dbiish repository is not valid anymore.
The DBIISH_MYSQL_LIB Env seems to be replaced by NativeLibs::Searcher with commit 9bc4191
Looking at NativeLibs::Searcher may help to find the root cause of the problem.
I've been having a dupliate host problem with nagios3 and check_mk from the Jessie repos.
After installing and config nagios3, I added my web.cfg for nagios.
I wanted to additional chekcs done by check_mk, so added the hosts to main.mk.
Then check_mk -I, -II and finally -U
-U will generate the first check_mk_commands but it contains an "host" definition. If I remove it and cat check_mk_commands > web.cfg it has depenceies problems.
If I remove the host definition from my web.cfg of nagios, there is still the same problem: duplicate host entry in "web.cfg"
I checked cfg_dir and nothing is included twice.
I am doing the same thing #work and it works.
Is there a way to tell check_mk not to do the host definition, I've spent 5 days of this.
Let me know if want some pasties, but I nailed the problem: check_mk does an host definition that is already in my nagios webserver monitoring configuration.
Removing the definition from one or the other doesn't work.
Even copyiing check_mk_commands.cfg without the host into my nagios3 config won't work due to missing templates.
Anyone encountered this problem ?
Please let me know, 6th day on this..
/usr/share/check_mk/modules/config.py has a variable that's called 'generate_hostconf' which is True by default.
If you change this to False, check_mk will not generate the host_config.
EDIT: This should be done in main.mk or any conf.d/*.mk files since it's not nice to edit core files.
/etc/check_mk/conf.d/no_host_config.mk:
generate_hostconf = False
I had a problem trying to get Apache Geode (v1.0.0-incubating.M2) running on Linux.
The problem was: while I was trying to run gfsh start server --name=server1 example command from the documentation it gave me the following error:
Exception in thread "main" com.gemstone.gemfire.InternalGemFireError: Cannot resolve local host name to an IP address.
It turns out that you need to have your hostname (given by output of hostname command) be present in /etc/hosts file.
In my case, hostname gives an alias as an output (let's say my_alias), so I solved the problem by adding my_ip my_full_domain my_alias line to /etc/hosts.
I have installed CDH4 on CentOS 6.3 64-bit in Pseudo Distributed mode using the following instructions. Everything is set to localhost in the Hadoop configuration files. But, still when I format the name node the below exception appears. When I add an 192.168.1.101 CentOSHost entry to the /etc/hosts file the exception goes away and I am able to run format/start HDFS and run MR jobs.
I want to run MR jobs even when I am not connected to the network without adding an entry to the /etc/hosts file. How to get this done?
12/08/27 22:17:15 WARN net.DNS: Unable to determine address of the host-falling back to "localhost" address
java.net.UnknownHostException: CentOSHost: CentOSHost
at java.net.InetAddress.getLocalHost(InetAddress.java:1360)
at org.apache.hadoop.net.DNS.resolveLocalHostIPAddress(DNS.java:283)
at org.apache.hadoop.net.DNS.(DNS.java:59)
at org.apache.hadoop.hdfs.server.namenode.NNStorage.newBlockPoolID(NNStorage.java:1017)
at org.apache.hadoop.hdfs.server.namenode.NNStorage.newNamespaceInfo(NNStorage.java:565)
at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:145)
at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:724)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1095)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1193)
It looks like some where the configuration is returning/ using the hostname as CentOSHost.
What does hostname --fqdn returns to you?
For Hadoop, it is important that name look-up and reverse look-up work successfully. You should be able to resolve the ip-address and resolve hostname from the ip-address (Reverse resolution). This can be tested using the above command.
The entry to /etc/hosts is required for the reverse resolution to work. Unless the entry and the configuration are pointing to localhost. Even in that case the hostname --fqdn should return as localhost.
I have configure ejabberd server 2.1.10 with mysql database integration,mod_admin_extra module and mod_xmlrpc module.
Issues is ejaberd admin commands like add_rosteritem, delete_rosteritem are notworking with xml_rpc.
When we use direct command line like,
*root#ejabberdserver:~# ejabberdctl add_rosteritem admin domain.com karthik domain.com karthik none both*
it will work and store in to database.
but same command does not work with xml_rpc.
xml_rpc does not return any error, it retun {ok,{response,[0]}}
But it does't store database.
Any permission issue?
Any body please help!!!!!
I meet the similar issue recently, and turn out the root cause was there a bug in (svn)ejabberd_module source code, and this was reported in https://github.com/processone/ejabberd-contrib/issues/22 and fixed in ejabberd-contrib,
So I suggest you download the source https://github.com/processone/ejabberd-contrib and rebuild the mod_admin_extra.