HI
As a daily check I have to check the SQL connection to all our servers. At the moment this is done by manually logging on through SQL server managment studio. I was just wondering if this can be coded in C# so that I can run it first thing in a morning and its checks each server and the instance for a valid SQL connection and reports back to say if the connection is live or not.
Thanks Andy
Here's a little console app example that will cycle through a list of connections and attempt to connect to each, reporting success or failure. Ideally you'd perhaps want to extend this to read in a list of connection strings from a file, but this should hopefully get you started.
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Text;
namespace SQLServerChecker
{
class Program
{
static void Main(string[] args)
{
// Use a dictionary to associate a friendly name with each connection string.
IDictionary<string, string> connectionStrings = new Dictionary<string, string>();
connectionStrings.Add("Sales Database", "< connection string >");
connectionStrings.Add("QA Database", "< connection string >");
foreach (string databaseName in connectionStrings.Keys)
{
try
{
string connectionString = connectionStrings[databaseName];
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
Console.WriteLine("Connected to {0}", databaseName);
}
}
catch (Exception ex)
{
// Handle the connection failure.
Console.WriteLine("FAILED to connect to {0} - {1}", databaseName, ex.Message);
}
}
// Wait for a keypress to stop the console closing.
Console.WriteLine("Press any key to finish.");
Console.ReadKey();
}
}
}
Look at the SqlConnection Class. It includes a basic sample. Just put a loop around that sample to connect to each server, and if any server fails to connect it throws an exception.
Then just set it up as a scheduled task in Windows.
A nice way to report the status might be with an email, which can easily be sent out with SmtpClient.Send (the link has a nice simple sample.
Why c#? You could make a simple batch file that does this using the osql command.
osql -S servername\dbname -E -Q "select 'itworks'"
You can also have a look at this method:
SqlDataSourceEnumerator.Instance.GetDataSources()
It gives you a list of SQL servers available on the network.
You know, they make monitoring tools that let you know if your sql server goes down . . .
Related
I have two SQL Server databases, server name are sql1 and sql2.
When I switch database from sql1 to sql2 (using HaProxy), my application still keeps the old SQL connection to server sql1.
However, other applications (using Linq-to-SQL) can get the new SQL connection to sql2.
Please see my code below that's I using to get connection to SQL Server:
using (var conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlserver"].ConnectionString))
{
using (SqlCommand command = new SqlCommand())
{
conn.Open();
//do something...
conn.Close();
return data;
}
}
What's my problem? How can I resolve this? Thanks!
You need to know the HAProxy listen configuration, maybe your HAProxy has exceptions programmed, or the redirection only works if you use an specific IP address destination or come from an specific IP range. Please compare the connections string used in each case.
https://www.stevefenton.co.uk/2016/11/load-balancing-microsoft-sql-server-with-haproxy/
I'm trying to automate configuring remote hosts, we have hundreds of these devices, we normally do it through USB programming, but if I could get a script to connect to these devices and do it programmatically, it would free up time.
These devices run some type of linux os, i'm not sure exactly, but they do have SSH enabled and confirm server host keys when you first connect to them via utility like PuTTY.
For now, i'm just trying to initiate an SSH session with the device. I've done quite a bit of research, and have come up with this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Renci.SshNet;
using Renci.SshNet.Common;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
//Connection information
string user = "admin";
string pass = "********";
string host = "IP Address";
//Set up the SSH connection
using (var client = new SshClient(host, user, pass))
{
//Accept Host key
client.HostKeyReceived += delegate (object sender, HostKeyEventArgs e)
{
e.CanTrust = true;
};
//Start the connection
client.Connect();
var output = client.RunCommand("show device details");
client.Disconnect();
Console.WriteLine(output.ToString());
Console.ReadLine();
}
}
}
}
The problem is this doesn't seem to execute the command listed. The console window comes up, and I can access the same device by WebGUI and see the log file, it shows a connection being made, but when I break the execution and see the variable values the output variable shows null.
If I let the execution sit, with the console window open (just shows a blinking cursor in the upper left), the connection times out after 10 minutes and connection is lost, which I also see happen in the device log.
Why would does this not seem to execute the runcommand and store the results in the output variable?
When you execute the RunCommand() method on an object of type Renci.SshNet.SshClient, it does not return the result as a variable.
Instead, it returns an object of the Renci.SshNet.SshCommand type.
The issue is that, it looks like you can't fit this resultant SshCommand object into a var.
This Renci.SshNet.SshCommand, returned when you execute RunCommand(), will contain several properties and methods.
The properties are:
CommandText
CommandTimeout
ExitStatus
OutputStream
ExtendedOutputStream
Result
Error
They're all useful, but as everything else seems to be working, the only relevant one you want is "Result".
The "Result" property will contain a String, which will be the host stream result of the command you provided to RunCommand().
As you mention the device's logfile has logged a successful connection being made, it looks like the connection is successful. So you'd just have to make the proper tweak to grab the Result, as described above, and you should be good to go.
Addendum:
The following line in the original post's code:
var output = client.RunCommand("show device details");
Should be replaced with this code:
var output = client.RunCommand("show device details").Result;
This will assign the Result property (which is a String) to the output var, which will give the desired outcome.
I am using this code but getting an error of 'Object reference not set to an instance of an object.' at con.open() ? what am I doing wrong ?
I have already download and installed ODAC component version 10 , 11 ,12 trying each one at the failure of the latest one but still same error
using Oracle.DataAccess.Client;
namespace WindowsFormsApplication1
{
class OraTest
{
public OracleConnection con = new OracleConnection();
public void Connect()
{
con.ConnectionString = "Data Source=(DESCRIPTION= (ADDRESS = (PROTOCOL = TCP)(HOST =myip) (PORT = myport))(CONNECT_DATA = (SERVER = dedicated)(SERVICE_NAME = mydb)));User ID=myid;Password=mypass;";
con.Open(); //error here
}
public void Close()
{
con.Close();
con.Dispose();
}
}
Please go through this link
Getting Started with Oracle Data Provider for .NET (C# Version)
http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/dotnet/GettingStartedNETVersion/GettingStartedNETVersion.htm
If you add a try/catch block in Connect(), you'll be able to catch the error.
For example:
When opening an oracle connection, connection object is null
I added the try catch block, and it returned ORA12154 - TNS could not
be resolved. After some research, I added an SID to my tnsnames.ora
file in my ODP for .NET Oracle home path, and it worked
See also Troubleshooting Oracle Net Services for troubleshooting possible connection issues from Oracle clients (such as your C# program).
But your first step is absolutely to determine the Oracle-level error (for example, ORA-12543 (could not connect to server host) or TNS-12514 (could not find service name)
MSDN: OracleException Class
public void ShowOracleException()
{
OracleConnection myConnection =
new OracleConnection("Data Source=Oracle8i;Integrated Security=yes");
try
{
myConnection.Open();
}
catch (OracleException e)
{
string errorMessage = "Code: " + e.Code + "\n" +
"Message: " + e.Message;
System.Diagnostics.EventLog log = new System.Diagnostics.EventLog();
log.Source = "My Application";
log.WriteEntry(errorMessage);
Console.WriteLine("An exception occurred. Please contact your system administrator.");
}
}
It's significant that con.ConnectionString = xyz works, but the following `con.Open()" fails. This means .Net is creating the C# object, but Oracle/TNS is failing when you try to use it.
ADDITIONAL SUGGESTIONS:
Re-read
When opening an oracle connection, connection object is null.
Read all of the suggestions, including the one about "Data Source in your connection string".
Focus on your connection string. It couldn't hurt to specify the connection string in your OracleConnection() constructor, if possible. Here's another link:
ODP.NET Connection exception
It would be great if you can verify connectivity from your PC with some other Oracle client, besides your C#/.Net program. To verify you're talking to the right TNS host and service, with the correct username/password. For example, maybe you have SQLDeveloper or sqlplus.
Finally, re-read the TNS troubleshooting link:
https://docs.oracle.com/cd/E11882_01/network.112/e41945/trouble.htm#NETAG016
What worked for me with the same error was to simply switch from the 'plain' Oracle DataAccess library, to the 'Managed' version.
This is an extemely easy change to make -
Add a Reference in your c# project to the Oracle.ManagedDataAccess library
Replace the existing use statements at the top of your Oracle client code with the following:
using Oracle.ManagedDataAccess.Client;
using Oracle.ManagedDataAccess.Types;
Include the Oracle.ManagedDataAccess.dll file with your exe
I need to find out if my database is running, and I have to do it in a WinForm in C#.
From the command prompt (in windows 7) I run the following command:
dbping -c "uid=sos;pwd=cdpbszqe;eng=mydatabase;dbn=mydatabase;links=tcpip" -pd file -d > result.txt
The result is written (redirected) to the result.txt file
which I open and see if it was successful
How can i do the same from in C# code using WinForms?
Is it possible to ping and get a result if successful?
Do I have to ping and create a text file from the ping result, then open it in my C# App?
What's the best way to proceed?
thanks.
No need for batch files if you just want to check if you can connect (i.e. it is running). We can test in a few line in C#.
private bool TestConnection()
{
using (var conn = new SqlConnection("connection string")
{
try
{
conn.Open();
return true;
}
catch(Exception ex)
{
//log exception
}
return false;
}
}
just create a batch file with above command and run it from your windows forms application using Process class. Get some help from :
Executing Batch File in C#
Which will create your result.txt file and you can read it using any File.ReadAllLines() or whatever method you want to use.
Newb questions incoming.
I'm running MySQL locally and I am having a really hard time connecting to it with C#.
Here's the code I'm using, much of the stuff I've tried out is commented out:
using System;
using System.Collections.Generic;
//using System.Data.Common.DbConnection;
using System.Threading;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Threading;
namespace mvpde
{
class Program
{
class DataReader_SQL
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
//
// TODO: Add code to start application here
//
try
{
OleDbConnection con = new OleDbConnection(#"Provider=sqloledb;Data Source=127.0.0.1:3306;database=database_name;User id=id;Password=password;");
con.Open();
//Thread.Sleep(9999);
//SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder();
//builder.DataSource = "localhost";
//builder.UserID = "hello";
//builder.Password = "password";
//builder.InitialCatalog = "db_123";
//SqlConnection thisConnection = new SqlConnection(builder.ToString());
//thisConnection.Open();
//SqlCommand thisCommand = thisConnection.CreateCommand();
//thisCommand.CommandText = "SELECT CustomerID, CompanyName FROM Customers";
//SqlDataReader thisReader = thisCommand.ExecuteReader();
//while (thisReader.Read())
//{
// Console.WriteLine("\t{0}\t{1}", thisReader["CustomerID"], thisReader["CompanyName"]);
//}
//thisReader.Close();
//thisConnection.Close();
}
catch (SqlException e)
{
Console.WriteLine(e.Message);
Thread.Sleep(9999999);
}
}
}
}
}
I've copied it nearly verbatim and tried to make it work from this site.
I have installed the MySQL on Windows 7 - I have created the user and the database I'm trying to access and I can do all this just fine using MySQL's own MySQL Workbench 5.2 CE software. I seem to have no clue what I'm doing using C# to connect to it.
All I want is to connect to it and send it a simple query like "USE DATABASE somedb" and then "SELECT TABLE sometable".
Errors I'm getting:
At first (when I used WAMP, before installing the MySQL package from mysql website) I would be able to connect once and see a login error; after that, it's as if the connection wasn't closed properly and I'd be unable to get even that far)
Now that I'm trying to connect to a MySQL instance that is created by MySQL's own software (or by running mysqld.exe) all I ever get is timeout problems\server not found\inaccessible.
Questions:
Am I using the wrong class?
What's the deal with "Provider="? where is the list of all the available variables for that part of the string? What does it mean? Why are the names involved so cryptic?
I imagined connecting to a locally-running MySQL server should be a breeze, but I've no idea what I'm doing.
Thank you.
You should use the MySql/Connector for DotNet.
Download it at this address then change your connection string accordingly.
For example "Server=127.0.0.1;Database=database_name;Uid=id;Pwd=password;Port=3306"
For other options, specific for MySQL, look at www.connectionstrings.com
have you had a look at http://www.connectionstrings.com/mysql ?
You can't use a SQL Connection object. You need a MySQL Connection object which is available in this library.http://www.connectionstrings.com/mysql
Download the MySQL Connection Library and use one of their connection strings provided on the site.
using MySql.Data.MySqlClient;
MySqlConnection myConnection = new MySqlConnection;();
myConnection.ConnectionString = myConnectionString;
myConnection.Open();
//execute queries, etc
myConnection.Close();
Then use the connection object to initalise the connection string and connect to MySQL