Develop Reference

C# code is unable to connect to Azure SQL database

I am trying to connect to a sample database I have created in Azure using C# (.NET Core 3.1)
I have enabled my IP address within Azure's Firewall rules.
I am able to use VS2019's SQL Server Object Explorer to connect and view the database within with no problems.
However, when I run a simple C# app on the same PC to execute a query to count the number of records in a table, it throws the following exception at the point where the connection is opened (conn.Open());
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The requested address is not valid in its context.)
The C# code;
using System;
using System.Data.SqlClient;
namespace AzureSql2
{
class Program
{
static void Main(string[] args)
{
string connStr = " Server=tcp:beaconsqlsql.database.windows.net,1433;Initial Catalog=MRP2;Persist Security Info=False;User ID=beaconadmin;Password=********;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;";
Console.WriteLine("Building connection");
try
{
using (var conn = new SqlConnection(connStr))
{
Console.WriteLine("Creating command");
using (var command = conn.CreateCommand())
{
command.CommandText = "SELECT COUNT(*) FROM [dbo].[Table]";
Console.WriteLine("Opening connection");
conn.Open();
Console.WriteLine("Reading database");
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine("Record count: {0}", reader.GetInt32(0));
}
}
}
}
}
catch (Exception ex)
{
Console.WriteLine("Exception: " + ex.Message);
}
Console.WriteLine("Press Enter to exit");
Console.ReadLine();
}
}
}
I've tried temporarily turning off the firewall on my PC, but that made no difference.
The fact that SQL Server Object Explorer can connect but the C# code cannot makes it sound like there's a problem with the C# code, but I can't see any differences between it and the samples I've looked at.

I created one Azure SQL database and allowed my client IP like below :-
I created one .Net Console application and ran your code, I replaced
using System.Data.SqlClient
with
using Microsoft.Data.SqlClient
You can use any of the above packages.
Copied connection string from Azure Portal > Azure SQL server > Connection string refer below :-
C# Code:-
using System;
using System.Linq.Expressions;
using Microsoft.Data.SqlClient;
namespace AzureSql2
{
class Program
{
static void Main(string[] args)
{
string connStr = "Server=tcp:sqlservername.database.windows.net,1433;Initial Catalog=sqldbname;Persist Security Info=False;User ID=username;Password=password;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;";
Console.WriteLine("Building connection");
try
{
using (var conn = new SqlConnection(connStr))
{
Console.WriteLine("Creating command");
using (var command = conn.CreateCommand())
{
command.CommandText = "SELECT * FROM Products";
Console.WriteLine("Opening connection");
conn.Open();
Console.WriteLine("Reading database");
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine("Record count: {0}", reader.GetInt32(0));
}
}
}
}
}
catch (Exception ex)
{
Console.WriteLine("Exception: " + ex.Message);
}
Console.WriteLine("Press Enter to exit");
Console.ReadLine();
}
}
}
Output :-
I tried to run the code with the connection string format you mentioned in the comments :-
Data Source=azuresqlservername.database.windows.net;Initial Catalog=databasename;User ID=siliconuser;Password=password;Connect Timeout=30;Encrypt=True;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False
And I was able to run the same code above and got the desired output:-
When I tried to change the Azure SQL server name in the connection string, I got the same error code as yours, refer below :-
Verify if your connection string has any syntax missing and validate it from Azure Portal.

I ended up taking a copy of the project home and running it on my home PC, and it worked correctly and reliably (after telling Azure to allow that IP address as well)
It turned out the answer was embarrassingly obvious - in addition to the standard Windows 10 firewall, my work PC is running another virus protection/firewall software, and that also needed to be told to allow the app thru.
Definitely one to remember for next time... Although I am kind of intrigued that on two occasions (once mentioned above, once afterwards) out of a few hundred attempts the app did manage to get thru and connect.
Thank you everyone for your answers and help.

Unable to work with SQL Server CE 4.0

I try to work with a SQL Server CE 4.0 database with my simple console app but it is not working on one of my machine.
OS: Windows Server 2003 Enterprise x64 Edition with Service Pack 2
I have also installed Microsoft SQL Server Compact 4.0 and used its dll (System.Data.SqlServerCe.dll) but every time I got following error
Unable to load the native components of SQL Server C
ADO.NET provider of version 8080. Install the correc
act. Refer to KB article 974247 for more details.
Here is my code
try
{
Console.WriteLine("Started");
var sqlConnectionString = "Data Source=c:\\tde\\22\\22.tde;password='sanjayraj';mode=Read Write;max database size=4091;temp file max size=4091";
_connection = new SqlCeConnection(sqlConnectionString);
_connection.Open();
var sqlStatement = "SELECT * FROM InfoStores WHERE Location = 'Source'";
IDbCommand newCommand = new SqlCeCommand
{
CommandText = sqlStatement,
Connection = _connection,
CommandType = CommandType.Text
};
using (IDataReader reader = newCommand.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(reader[0].ToString());
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error Occured");
Console.WriteLine(ex.Message);
Console.ReadKey();
}
Console.WriteLine("Finished");
Console.ReadKey();

You a referenceing the wrong version of System.data.SqlServerCe.dll, use the one in the C:\Program Files (x86)\Microsoft SQL Server Compact Edition\v4.0\Desktop folder

How to tell if SQL Server automated upgrade is successful from C# WinForms app

I'm automating an upgrade of SQL Server 2005 Express to SQL Server 2008R2 Express via a WinForms app that is used to upgrade our application. The application is deployed at some 800+ locations, so we don't want any manual steps.
I've got the following code mostly written to perform the upgrade. I need to know, what's best practice for determining if the SQL Server installer completed successfully? Should I just look for an exit code of 0 for the process? Is that good enough; i.e. could it still exit with code of 0 if the upgrade had a problem and was rolled back (I'd test this, but don't know the best way to simulate a failure)?
Is there any other way to determine if the upgrade was successful in my C# app, so I can handle it properly if there was any error encountered by the SQL Server Installer?
try
{
//First, find the version of the currently installed SQL Server Instance
string sqlString = "SELECT SUBSTRING(CONVERT(VARCHAR, SERVERPROPERTY('productversion')), 0, 5)";
string sqlInstanceVersion = string.Empty;
using (DbCommand cmd = _database.GetSqlStringCommand(sqlString))
{
sqlInstanceVersion = cmd.ExecuteScalar().ToString();
}
if (sqlInstanceVersion.Equals(String.Empty))
{
//TODO throw an exception or do something else
}
//11.00 = SQL2012, 10.50 = SQL2008R2, 10.00 = SQL2008, 9.00 = SQL2005, 8.00 = SQL2000
switch (sqlInstanceVersion)
{
case "11.00":
case "10.50":
case "10.00":
//Log that the version is already up to date and return
return;
case "9.00":
case "8.00":
//We are on SQL 2000 or 2005, so continue with upgrade to 2008R2
break;
default:
//TODO throw an exception for unsupported SQL Server version
break;
}
string upgradeArgumentString = "/Q /ACTION=upgrade /INSTANCENAME={0} /ENU /IACCEPTSQLSERVERLICENSETERMS";
string instanceName = "YourInstanceNameHere";
string installerFilePath = AppDomain.CurrentDomain.BaseDirectory + "\\SQLEXPR_x86_ENU.exe";
if (!File.Exists(installerFilePath))
{
throw new FileNotFoundException(string.Format("Unable to find installer file: {0}", installerFilePath));
}
Process process = new Process
{
StartInfo = { FileName = installerFilePath, Arguments = String.Format(upgradeArgumentString, instanceName), UseShellExecute = false }
};
process.Start();
if (process.WaitForExit(SQLSERVER_UPGRADE_TIMEOUT))
{
//Do something here when the process completes within timeout.
//What should I do here to determine if the SQL Server Installer completed successfully? Look at just the exit code?
}
else
{
//The process exceeded timeout. Do something about it; like throw exception, or whatever
}
}
catch(Exception ex)
{
//Handle your exceptions here
}

Look at the full version string, nut just the first 5 chars of it. A successful upgrade will change the version string.

Copying databases between sql servers

I am developing a Web Application for copying data between SQL Servers. The tool will let you specify which server you are copying from/to and will then copy a specific database (which always has the same name) from the source server to the destination server.
What is the best method to do this? The data could be quite large, so speed needs to be taken into account also.
My attempt at this is to try to run an SSIS package that I created using SQL Server Management Studio. The package is stored locally.
The plan is to modify the Source and Destination connection strings and kick off the package.
This is my code for doing so:
public void DataTransfer(String sourceConnection, String destConnection, String pkgLocation)
{
Package pkg;
Application app;
DTSExecResult pkgResults;
try
{
app = new Application();
pkg = app.LoadPackage(pkgLocation, null);
foreach (ConnectionManager connectionManager in pkg.Connections)
{
SqlConnectionStringBuilder builder;
switch (connectionManager.Name)
{
case "SourceConnection":
builder = new SqlConnectionStringBuilder(sourceConnection);
builder.Remove("Initial Catalog");
builder.Add("Initial Catalog", "StagingArea");
var sourceCon = builder.ConnectionString + ";Provider=SQLNCLI;Auto Translate=false;";
//Added spaces to retain password!!!
sourceCon = sourceCon.Replace(";", "; ");
connectionManager.ConnectionString = sourceCon;
Debug.WriteLine(connectionManager.ConnectionString.ToString());
break;
case "DestinationConnection":
builder = new SqlConnectionStringBuilder(destConnection);
builder.Remove("Initial Catalog");
builder.Add("Initial Catalog", "StagingArea");
var destCon = builder.ConnectionString + ";Provider=SQLNCLI;Auto Translate=false;";
//Added spaces to retain password!!!
destCon = destCon.Replace(";", "; ");
connectionManager.ConnectionString = destCon;
Debug.WriteLine(connectionManager.ConnectionString.ToString());
break;
}
}
pkgResults = pkg.Execute();
}
catch (Exception e)
{
throw;
}
Debug.WriteLine(pkgResults.ToString());
}
When pkg is executed I get the following exceptions:
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in Microsoft.SqlServer.ManagedDTS.dll
A first chance exception of type 'Microsoft.SqlServer.Dts.Runtime.DtsComponentException' occurred in Microsoft.SqlServer.ManagedDTS.dll
I'm not really sure where to go from here, any ideas?

I would write an SSIS package to do the data copying / transformation and the website would simply configure the connection string and kick off the package.

Detect local SQL server installation with C#(32 bit as well as 64 bit)

How can I detect if SQL is installed on the local machine using C#? Is it possible to check a remote machine?

You've got several ways to do it:
SmoApplication.EnumAvailableSqlServers()
SqlDataSourceEnumerator.Instance
Direct access to system registry
Direct access isn't the recommended solution by MS, because they can change keys/paths. But the other solutions fails providing instances on 64-bit platforms.
Therefore I prefer to check SQL Server instances in System Registry. Doing that, keep in mind the difference in Registry access between x86 and x64 platforms. Windows 64-bit stores data in different parts of system registry and combines them into views. So using RegistryView (available since .NET 4) is essential.
using Microsoft.Win32;
RegistryView registryView = Environment.Is64BitOperatingSystem ? RegistryView.Registry64 : RegistryView.Registry32;
using (RegistryKey hklm = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, registryView))
{
RegistryKey instanceKey = hklm.OpenSubKey(#"SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL", false);
if (instanceKey != null)
{
foreach (var instanceName in instanceKey.GetValueNames())
{
Console.WriteLine(Environment.MachineName + #"\" + instanceName);
}
}
}
If you are looking for 32-bit instances on a 64-bit OS (pretty weird, but possible), you will need to look:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Microsoft SQL Server

You can check registry path
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\InstalledInstances
For an example of code that does similar work, see this quesion how-to-get-sql-server-installation-path-programatically
Please also see MSDN: File Locations for Default and Named Instances of SQL Server for more details on registry keys used by SQL Server.

We check the registry for that
Registry.GetValue(#"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\MSSQLServer\CurrentVersion", ", "0.0.0.0");

You could use the System.Management namespace to check for the existence of SQL Server in the server's running services.

You will need SQL 2005 Backwards Compatibility redist.
See: How to Connect to Sqlserver2008 using SMO any workaround has to be done?
using Microsoft.SqlServer.Management.Smo;
DataTable dt = SmoApplication.EnumAvailableSqlServers(true);
string[] szSQLInstanceNames = new string[dt.Rows.Count];
StringBuilder szSQLData = new StringBuilder();
if (dt.Rows.Count > 0)
{
int i = 0;
foreach (DataRow dr in dt.Rows)
{
try
{
szSQLInstanceNames[i] = dr["Name"].ToString();
Server oServer;
oServer = new Server(szSQLInstanceNames[i]);
if (string.IsNullOrEmpty(dr["Instance"].ToString()))
{
szSQLInstanceNames[i] = szSQLInstanceNames[i] + "\\MSSQLSERVER";
}
szSQLData.AppendLine(szSQLInstanceNames[i] + " Version: " + oServer.Information.Version.Major + " Service Pack: " + oServer.Information.ProductLevel + " Edition: " + oServer.Information.Edition + " Collation: " + oServer.Information.Collation);
}
catch (Exception Ex)
{
szSQLData.AppendLine("Exception occured while connecting to " + szSQLInstanceNames[i] + " " + Ex.Message);
}
i++;
}
Note: if you just want to see if Default intance is installed or no just do:
Server oServer;
oServer = new Server(Environment.MAchineName);
if it does not throw an exception, the SQL exists.

Perhaps you'll find the following useful. Use first method to find about servers (local & network), then you can use the second to enumerate databases on each server.
using System;
using System.Collections.Generic;
using System.Data.Sql;
using System.Data;
using System.Data.SqlClient;
namespace Info.Data.Engine.SQLServer
{
public static class SQLServerHelper
{
public static List<String> EnumerateServers()
{
var instances = SqlDataSourceEnumerator.Instance.GetDataSources();
if ((instances == null) || (instances.Rows.Count < 1)) return null;
var result = new List<String>();
foreach (DataRow instance in instances.Rows)
{
var serverName = instance["ServerName"].ToString();
var instanceName = instance["InstanceName"].ToString();
result.Add(String.IsNullOrEmpty(instanceName) ? serverName : String.Format(#"{0}\{1}", serverName, instanceName));
}
return result;
}
public static List<String> EnumerateDatabases(String connectionString)
{
try
{
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
var databases = connection.GetSchema("Databases");
connection.Close();
if ((databases == null) || (databases.Rows.Count < 1)) return null;
var result = new List<String>();
foreach (DataRow database in databases.Rows)
{
result.Add(database["database_name"].ToString());
}
return result;
}
}
catch
{
return null;
}
}
}
}
HTH,
Dejan

You could just open a connection to the machine and close it. If you throw an exception that's a decent sign. I realize it's not super clean but it'll get the job done.

Thanks a lot to Dejan Stanič.
And I wanted to add more search criteria:
Check if SQL Server 2008 is installed on local machine in .net sqlclient