Develop Reference

Dynamically creating a connection string for a database just created

I have created a database programmatically.
Is there any way to create its connection string dynamically using C#, so that after the database creation all data is stored in the new database using C#.

You could also used nuget which will create ConnectionString for you.
After installing package
Install-Package ConnectionStringPT
You will just need to invoke:
var connectionString = ConnectionString.GetSqlServerConnectionString("localhost", "dbName");

I have use this in my C# widows form app and it works for me. Change it according to your needs.
You need to add namespace:
//using Microsoft.SqlServer.Management.Smo;
using System.Data.SqlClient;
and add below code:
try
{
SqlConnectionStringBuilder _connectionString = new SqlConnectionStringBuilder();
_connectionString.DataSource = #".\SQLEXPRESS";
_connectionString.InitialCatalog = "databaseName"; //add database name which created dynamically
_connectionString.IntegratedSecurity = true;
}
catch(Exception ex)
{
MessageBox.Show("Not able to create connection string. Error : " +ex);
}

Copy database with smo raise error: "user already exists"

I try to copy a database using smo, but I get the error:
"User, group, or role '%' already exists in the current database"
My code:
var conn = GetServerConnection();
var server = new Server(conn);
var sourceDb = server.Databases[sourceDatabase.Name];
var destinationDbName = GetNameForDatabase(dbName);
var destinationDb = new Database(server, destinationDbName);
destinationDb.Create();
var transfer = new Transfer(sourceDb) {
DestinationDatabase = destinationDbName,
DestinationServer = server.Name,
DestinationLoginSecure = true,
CopySchema = true,
CopyAllTables = true,
CopyData = true,
CopyAllUsers = false,
};
transfer.Options.WithDependencies = true;
transfer.Options.ContinueScriptingOnError = true;
transfer.TransferData();
Thanks in advance for any suggestions!

Do you have any mappings from the database server to the source database? Try removing those before attempting the copy.
I was copying the database using the Copy Database wizard in order to create a test database on the same server, and got this error. The problem was that the source database had a user login mapped to that database. Somewhere in the mix of it all, the Copy Database wizard was trying to add a user to the destination database via a straight copy, but also add the same user through the mapping. The trick was to remove the mapping of the source database, then copy the database, then add the mapping back to the source (it was already added at the destination).

Error while connecting to sql through windows authentication

I am using the following code to connect to sql throgh windows authentication.
string connctionstring = "connectionString={0};Database={1};Integrated Security=SSPI;";
string _connctionstring = string.Format(connctionstring, datasource, initialCatalogue);
SqlConnection _connection = new SqlConnection(_connctionstring);
_connection.Open();
But i am getting the following error. Help please.I am able to login through sql server.

The connection string format is not correct
Change to this:
string connctionstring = "Data Source={0};Database={1};Integrated Security=SSPI;";
Or
string connctionstring = "Server={0};Database={1};Integrated Security=SSPI;";

While Peyman's answer does cover the basic issue (connectionString is not a valid key for the string) a better solution is to use a SqlConnectionStringBuilder, this will also help you do proper escaping if you have odd characters in your string (for example if your database name contained a space)
var scsb = new SqlConnectionStringBuilder();
scsb.DataSource = datasource;
scsb.InitialCatalog = initialCatalogue;
scsb.IntegratedSecurity = true;
//You also really should wrap your connections in using statements too.
using(SqlConnection connection = new SqlConnection(scsb.ConnectionString))
{
connection.Open();
//...
}

Entity Framework runtime connection string

I'd like to supply the connection string for my database at runtime. I am using the Entity Framework. This is what I have so far
class MyClassDBContext:DbContext
{
public MyClassDBContext(string str) : base(str)
{
this.Database.Connection.ConnectionString = str;
}
}
To use the above code, I tried
//create connection string
EntityConnectionStringBuilder myConn = new EntityConnectionStringBuilder();
myConn.Provider = "System.Data.SqlClient";
myConn.ProviderConnectionString = "user id=xxxx;password=xxxx;server=localhost;database=xxxx;connection timeout=30";
//inject the connection string at runtime
MyClassDBContext a = new MyClassDBContext(myConn.ToString())
The above code gave me an error saying "Provider keyword not supported".
To attempt to debug this error, I tried the following
MyClassDBContext a = new MyClassDBContext("metadata=res://*/Model.csdl|res://*/Model.ssdl|res://*/Model.msl;provider=System.Data.SqlClient;provider connection string=user id=xxxx;password=xxxx;server=localhost;database=xxxx;connection timeout=30")
Now, I got an error saying "metadata keyword not supported". So I changed my code to
MyClassDBContext a = new MyClassDBContext("provider=System.Data.SqlClient;provider connection string=user id=xxxx;password=xxxx;server=localhost;database=xxxx;connection timeout=30")
Now I got an error saying "provider keyword not supported". So I again changed my code to
MyClassDBContext a = new MyClassDBContext("user id=xxxx;password=xxxx;server=localhost;database=xxxx;connection timeout=30")
and now it works!. My question is : how do I specify the provider and metadata at runtime? It looks like only the connection string is being accepted. I am using Entity 4.3.1 from Nuget.
Thanks

edmx file based EF require the "Provider" and "Metadata" content. Code-first based EF doesn't require this, requiring only the regular connection string. You could use a SqlConnectionStringBuilder (instead of EntityConnectionStringBuilder) to build this normal connection string if you'd like. But as you've seen, you need only specify the actual connection details. The Provider and Metadata aren't needed in EF 4.3.1's DbContext Code-first paradigm.

Building on HatSoft's answer:
var entityConnectionStringBuilder= new EntityConnectionStringBuilder();
entityConnectionStringBuilder.Provider = "System.Data.SqlClient";
entityConnectionStringBuilder.ProviderConnectionString = <your SQL Server connection string>;
entityConnectionStringBuilder.Metadata = "res://*";
MyClassDBContext a = new MyClassDBContext(entityConnectionStringBuilder.ToString());

The EntityConnectionStringBuilder class can be used to to specify provider and metadata at runtime
e.g.
var entityConnectionStringBuilder= new
EntityConnectionStringBuilder();
entityConnectionStringBuilder.Provider = "System.Data.SqlClient";
entityConnectionStringBuilder.Metadata =
"res:///Example.csdl|res:///Example.ssdl|res://*/Example.msl";
Please see for more on CSDL, SSDL & MSDL in Metadata

I followed this link
and also this one
How to use EF Code-First without an app.conf file?
Basically what I do is almost like you, create a constructor with a string and calling the base.
But I also set the provider in this constructor.
here's a example
public Context(string ConnectionString) : base(ConnectionString) {
Database.DefaultConnectionFactory = new SqlCeConnectionFactory("Oracle.DataAccess.Client");
}
That way you can specify the provider. And you won't get the provider keyword error since you don't need to specify in the connection string
Here's how I call it.
var dbCont = new ClassLibrary1.Models.Context("DATA SOURCE=xxx;PASSWORD=xxx;USER ID=xxx");
Hope that helps took me long time to find it

It's old question but maybe it will be useful for someone
var provider = (DbProviderFactory)System.Data.Entity.DbConfiguration
.DependencyResolver
.GetService(typeof(DbProviderFactory), "invariant provider name");
var conn = provider.CreateConnection();
//conn.ConnectionString = "sample connection string";
DbInterception.Dispatch.Connection.SetConnectionString(conn, new DbConnectionPropertyInterceptionContext<string>()
.WithValue("sample connection string"));
return new SampleDbContext(conn,true);

Connect to AS400 using .NET

I am trying to build a .NET web application using SQL to query AS400 database. This is my first time encountering the AS400.
What do I have to install on my machine (or the AS400 server) in order to connect?
(IBM iSeries Access for Windows ??)
What are the components of the connection string?
Where can I find sample codes on building the Data Access Layer using SQL commands?
Thanks.

You need the AS400 .Net data provider. Check here:
https://www-01.ibm.com/support/docview.wss?uid=isg3T1027163
For connection string samples, check here:
https://www.connectionstrings.com/as-400/
Also, check out the redbook for code examples and getting started.
http://www.redbooks.ibm.com/redbooks/pdfs/sg246440.pdf

Following is what I did to resolve the issue.
Installed the IBM i Access for Windows. Not free
Referred the following dlls in the project
IBM.Data.DB2.iSeries.dll
Interop.cwbx.dll (If Data Queue used)
Interop.AD400.dll (If Data Queue used)
Data Access
using (iDB2Command command = new iDB2Command())
{
command.Connection = (iDB2Connection)_connection;
command.CommandType = CommandType.Text;
command.Parameters.AddWithValue(Constants.ParamInterfaceTransactionNo, 1);
command.CommandText = dynamicInsertString;
command.ExecuteScalar();
}
Connection String
<add name="InterfaceConnection"
connectionString="Data Source=myserver.mycompany.com;User ID=idbname;Password=mypassxxx;
Default Collection=ASIPTA;Naming=System"/>
UPDATE
i Access for Windows on operating systems beyond Windows 8.1 may not be supported. Try the replacement product IBM i Access Client Solutions
IBM i Access Client Solutions

As mentioned in other answers, if you have the IBM i Access client already installed, you can use the IBM.Data.DB2.iSeries package.
If you don't have the IBM i Access software, you can leverage JTOpen and use the Java drivers. You'll need the nuget package JT400.78 which will pull in the IKVM Runtime.
In my case I needed to query a DB2 database on an AS400 and output a DataTable. I found several hints and small snippets of code but nothing comprehensive so I wanted to share what I was able to build up in case it helps someone else:
using com.ibm.as400.access;
using java.sql;
var sql = "SELECT * FROM FOO WITH UR";
DriverManager.registerDriver(new com.ibm.as400.access.AS400JDBCDriver());
Connection conn = DriverManager.getConnection(
"jdbc:as400:" + ServerName + ";prompt=false", UserName, Password);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
int ct = md.getColumnCount();
DataTable dt = new DataTable();
for(int i=1; i<=ct; i++)
dt.Columns.Add(md.getColumnName(i));
while (rs.next())
{
var dr = dt.NewRow();
for (int i = 1; i <= ct; i++)
dr[i - 1] = rs.getObject(i);
dt.Rows.Add(dr);
}
rs.close();
The conversion from RecordSet to DataTable is a little clunky and gave me bad flashbacks to my VBScript days. Performance likely isn't blinding fast, but it works.

Extremely old question - but this is still relevant. I needed to query our AS/400 using .NET but none of the answers above worked and so I ended up creating my own method using OleDb:
public DataSet query_iseries(string datasource, string query, string[] parameterName, string[] parameterValue)
{
try
{
// Open a new stream connection to the iSeries
using (var iseries_connection = new OleDbConnection(datasource))
{
// Create a new command
OleDbCommand command = new OleDbCommand(query, iseries_connection);
// Bind parameters to command query
if (parameterName.Count() >= 1)
{
for (int i = 0; i < parameterName.Count(); i++)
{
command.Parameters.AddWithValue("#" + parameterName[i], parameterValue[i]);
}
}
// Open the connection
iseries_connection.Open();
// Create a DataSet to hold the data
DataSet iseries_data = new DataSet();
// Create a data adapter to hold results of the executed command
using (OleDbDataAdapter data_adapter = new OleDbDataAdapter(command))
{
// Fill the data set with the results of the data adapter
data_adapter.Fill(iseries_data);
}
return iseries_data;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
return null;
}
}
And you would use it like so:
DataSet results = query_iseries("YOUR DATA SOURCE", "YOUR SQL QUERY", new string[] { "param_one", "param_two" }, new string[] { "param_one_value", "param_two_value"});
It returns a DataSet of the results returned. If anyone needs/wants a method for inserting/updating values within the IBM AS/400, leave a comment and I'll share...

I'm using this code and work very good for me!
Try
Dim sqltxt As String = "SELECT * FROM mplib.pfcarfib where LOTEF=" & My.Settings.loteproceso
dt1 = New DataTable
Dim ConAS400 As New OleDb.OleDbConnection
ConAS400.ConnectionString = "Provider=IBMDA400;" & _
"Data Source=192.168.100.100;" & _
"User ID=" & My.Settings.usuario & ";" & _
"Password=" & My.Settings.contrasena
Dim CmdAS400 As New OleDb.OleDbCommand(sqltxt, ConAS400)
Dim sqlAS400 As New OleDb.OleDbDataAdapter
sqlAS400.SelectCommand = CmdAS400
ConAS400.Open()
sqlAS400.Fill(dt1)
grid_detalle.DataSource = dt1
grid_detalle.DataMember = dt1.TableName
Catch ex As Exception
DevExpress.XtraEditors.XtraMessageBox.Show("Comunicación Con El AS400 No Establecida, Notifique a Informatica..", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Me.Close()
End Try

I recently found the ADO.Net driver available on NuGet. I have the iSeries client access installed on my PC, so I can't say if it works as a standalone, but it does connect. Theonly problem is I can't actually see any tables or procedures. I think there may be a schema or library or something I still haven't gotten down to. I will post if I find the answer. Meanwhile I can still get to the server and write most of my code with the NuGet adapter.

Check out http://asna.com/us/ as they have some development tools working with SQL and the AS400.