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Cannot set Connection String to LocalDb using OLEDB

Good morning guys,
I feel quite silly to ask this question, but I have looked everywhere and possibly at all questions in this matter and could not find a solution that would work for me.
Long story short.
I am using a local database called TestDB.mdf in windows form application. The application is designed to do (as per current) two simple things.
1. Import data from excel document into the database - which I don't have any issues with.
and...
2. Clear all data stored in that database - this is where I am struggling
For the import data into the database (point 1) I am using two connection strings. One for excelConnectionString
string excelConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " +
"C:\\Users\\User.AR\\Desktop\\export.xls; " +
"Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1;\"";
and second for sqlConnectionString
string sqlConnectionString = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=c:\users\arkadiusz.rzepka\source\repos\Database_application\Database_application\TestDB.mdf;Integrated Security=True";
Then I use SqlBulkCopy to import all data and all is working like a charm.
Now the issue I can see is that I cannot open a connection to clear all data from the same database.
I have navigated to properties of my database to find connection string and this has been presented in the below format:
Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\User.AR\source\repos\Database_application\Database_application\TestDB.mdf;Integrated Security=True
I have had to amend the above connection string as I was getting errors such as missing provider, should be like Provider=SQLOLEDB, after adding a provider, I have had to change Integrated Security = SSPI, and now I am getting error such as SQL Server does not exist or access denied
My code just to check if the connection was opened is presented below and I would be grateful if you could advise of what I am doing wrong.
private void DeleteAllRecords()
{
string connectionString = #"Provider=Sqloledb;Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\User.AR\source\repos\Database_application\Database_application\TestDB.mdf;Integrated Security=SSPI";
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
try
{
connection.Open();
MessageBox.Show("Connection openned successfully!");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}

If you run this in the command prompt.
SqlLocalDB.exe i "MSSQLLocalDB"
You will get the instance pipe name. You should be able to use that in your OLEDB connection. This has worked for me when connecting Excel using OLEDB connection to my MSSQLLocalDB.
Name: MSSQLLocalDB
Version: 13.1.4001.0
Shared name:
Owner: Foo\Foo.Bar
Auto-create: Yes
State: Running
Last start time: 18/03/2021 09:00:34
Instance pipe name: np:\\.\pipe\LOCALDB#DA1FAFF6\tsql\query
So my final connection string in excel looked like this.
provider=SQLOLEDB;initial catalog=IpsosDC;data source=np:\\.\pipe\LOCALDB#DA1FAFF6\tsql\query

Try using double bar on the paths of your connection strings, instead of one. So it would be like this:
string connectionString = #"Provider=Sqloledb;Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\Users\\User.AR\\source\\repos\\Database_application\\Database_application\\TestDB.mdf;Integrated Security=SSPI";

Not inserting data into database and not getting any error

I am not sure what I am doing wrong, If I use the connection string shown here, my application works fine.
SqlConnection conn = new SqlConnection();
string DbPath = Application.StartupPath;
DbPath = DbPath.Substring(0, DbPath.LastIndexOf("\\bin"));
DbPath = DbPath + "\\MyDatabase.mdf";
conn.ConnectionString = "Data Source=.\\EXPRESS2008;AttachDbFilename=" + DbPath + ";Integrated Security=True;User Instance=True";
but if I use connection string here, it's not inserting data into MyDatabase table
conn.ConnectionString = Properties.Settings.Default.MyDatabaseConnectionString;
My app.config is
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<connectionStrings>
<add name="ERPSystem.Properties.Settings.MyDatabaseConnectionString"
connectionString="Data Source=.\EXPRESS2008; AttachDbFilename=|DataDirectory|\MyDatabase.mdf;Integrated
Security=True;User Instance=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
INSERT statement and preceding code:
comm = new SqlCommand("CreateUser", MyConnection.MyConn("Open"));
comm.CommandType = CommandType.StoredProcedure;
comm.Parameters.Add("#UserName", SqlDbType.VarChar).Value = userName.Text;
comm.Parameters.Add("#Password", SqlDbType.VarChar).Value = userPassword.Text;
comm.Parameters.Add("#UserRole", SqlDbType.VarChar).Value = UserRole.SelectedItem.ToString();
comm.ExecuteNonQuery();
This is the code to get the connection
class MyConnection
{
public static SqlConnection MyConn(string str)
{
SqlConnection conn = new SqlConnection();
try
{
//get application path
string DbPath = Application.StartupPath;
if (Program.RunFrEn == true) //bool var
//remove string after bin folder
DbPath = DbPath.Substring(0, DbPath.LastIndexOf("\\bin"));
//add database name with new path
DbPath = DbPath + "\\MyDatabase.mdf";
//generate new connection string for database
conn.ConnectionString = "Data Source=.\\EXPRESS2008;AttachDbFilename="
+ DbPath
+ ";Integrated Security=True;User Instance=True";
//conn.ConnectionString = Properties.Settings.Default.MyDatabaseConnectionString;
if (str == "Open")
{
if (conn.State == ConnectionState.Closed)
conn.Open();
}
else
{
if (conn.State == ConnectionState.Open)
conn.Close();
}
}
catch (System.Data.SqlClient.SqlException ex)
{
MessageBox.Show(ex.Message);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
return conn;
}
}
I am not getting any error
Thank you

The whole AttachDbFileName= approach is flawed - at best! When running your app in Visual Studio, it will be copying around the .mdf file (from your App_Data directory to the output directory - typically .\bin\debug - where you app runs) and most likely, your INSERT works just fine - but you're just looking at the wrong .mdf file in the end!
If you want to stick with this approach, then try putting a breakpoint on the myConnection.Close() call - and then inspect the .mdf file with SQL Server Mgmt Studio Express - I'm almost certain your data is there.
The real solution in my opinion would be to
install SQL Server Express (and you've already done that anyway)
install SQL Server Management Studio Express
create your database in SSMS Express, give it a logical name (e.g. MyDatabase)
connect to it using its logical database name (given when you create it on the server) - and don't mess around with physical database files and user instances. In that case, your connection string would be something like:
Data Source=.\\SQLEXPRESS;Database=MyDatabase;Integrated Security=True
and everything else is exactly the same as before...
Also see Aaron Bertrand's excellent blog post Bad habits to kick: using AttachDbFileName for more background info.

I also had fighted long time with same problem. And I saw many same questions & answers.
You're using |DataDirectory|. I assume you can get values from the DB file and you don't get error to run insert command but the values are not inserted into the DB file.
This is absolutely my private idea and my private conclusion is that this behavior is normal as |DataDirectory| does. I mean a data file of an application should be protected from manipulation once after deployment. The 'Data' file should provide data inside the file so that we can read the data.
Therefore, I coded to create a localDB .MDF file (SQL Server 2014) from users' side so that my applications can utilize the localDB to write and read data. My application automatically downloads data from cloud server which are we need to update frequently. On the other side, I put big and already fixed data into |DataDirectory| .MDF file, I mean inserted big data for read only and add the .MDF file to my project before deployment.
Hope my experience helps.. But, please keep in mind again that this is really my private opinion and I might be totally wrong and my experience is limited only to localDB. But again, I couldn't find a Microsoft's official document mentioning this behavior.
Do you have only 1 option like |DataDirectory|? Did this work to insert before? Is this code by you wrote on your own? If possible, try to find another option rather than |DataDirectory| to connect to the SQL Server database. I use a cloud SQL server with IP address but I can't understand why you use |DataDirectory|. There might be many various options as connection strings to SQL Server Express.

connection string in c#

I have to access data from an MS Access DB stored in a central server.What should be the connection string in c# for it? Currently the connection string for the access database stored in my local machine is as follows:
string ConnectionString = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\GAURASI\Documents\Visual Studio 2013\Projects\IMPACT\PACEDB.accdb;Jet OLEDB:Database Password=PACE#impact";

Provider=Microsoft.ACE.OLEDB.12.0;
Data Source=\\server\share\folder\myAccessFile.accdb;
Refer this

Creating an SQL Server connection string without importing a datasource in C#

I am going off of this tutorial: http://www.dotnetperls.com/sqlclient . Instead of adding a data source and a having visual studio compile my connecting string - I want to do it myself. The reason being is that the database will not always be the same and I want this application to be able to use different databases depending on which I point it to.
So how can I manually create the connection string? I am using SQL Server 2005.

Step 1: Go to connectionstrings.com and find the proper format for your database.
Step 2: Plug in the appropriate values to the connection string.
Step 3: Pass that string to the constructor of SqlConnection.
I would also suggest storing your connection string in your app.config/web.config file. You can then modify them easily if needed. The proper format can be found at MSDN - connectionStrings element. You then change your code to:
SqlConnection sqlConn = new SqlConnection(
ConfigurationManager.ConnectionStrings["ConnStringName"].ConnectionString);

I don't see where the connection string is "compiled".
In the code
SqlConnection con = new SqlConnection(
ConsoleApplication1.Properties.Settings.Default.masterConnectionString)
ConsoleApplication1.Properties.Settings.Default.masterConnectionString is a field and it can be replaced with any other appropriate string.

for SQL Server format of the connection string is
"Data Source = server_address; Initial Catalog = database_name; User ID = UserId; Password = **;"
save this connection string in a string variable and use with connection object.
either way you can add in web.config file.
<ConnectionString>
<add name = "name_of_connecctionString" ConnectionString = "Data Source = server_address; Initial Catalog = database_name; User ID = UserId; Password = ****;" ProviderName = "system.Data.SqlClient"/>
</ConnectionString>
you can change the provider as needed by you.
then in code behind file access this particular connection string using configuration manager.

Error trying to connect to SQL Server using C#

My code is as follows:
string constring = "Data Source=132.186.127.169"+ "Initial Catalog=CadPool1;" + "Integrated Security=True";
SqlConnection con;
con = new SqlConnection(constring);
con.Open();
string query="SELECT * from CadPoolProjectTable1";
SqlCommand cmd = new SqlCommand(query, con);
cmd.ExecuteNonQuery();
MessageBox.Show("selected");
con.Close();
I am getting error at the line con.Open();. The error is:
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: Named Pipes
Provider, error: 40 - Could not open a
connection to SQL Server)

You are missing a ';' after the server name in the connection string.
string constring = "Data Source=132.186.127.169"+ "Initial Catalog=CadPool1;" + "Integrated Security=True";
It should be
string constring = "Data Source=132.186.127.169;"+ "Initial Catalog=CadPool1;" + "Integrated Security=True";
The error says that your app was not able to connect to the server. I would do the following.
Check for the server address (on a quick look it looks good)
Connect using management studio and in your case it should have worked.
It means the issue is with the code. Since you are concatenating the string I would debug the code and see what the end result for the connection string is.
Tip:If it is a web application add the connection string to web.config file. More info here How to: Read Connection Strings from the Web.config File

You're missing a semicolon in your connection string
Data Source=132.186.127.169;"+ "Initial...
^
If you need to build the connection string yourself you can use the SqlConnectionStringBuilder class. That way you won't to be as troubled by these subtle mistakes.

Your connection string is wrong:
string constring =
"Data Source=132.186.127.169;Initial Catalog=CadPool1;Integrated Security=True";
You don't need to concatenate the strings together, but more importantly, you were missing the semi-colon ";" between the data source and the initial catalog settings.

First, you are missing a ; (semicolon) between Data Source and Initial Catalog.
Second, if this is a newly installed SQL Server instance, you may need to go into SQL Server Configuration Manager, and enable the protocol(s) you'll need.

Please check if you can ping the server mentioned via cmd
Also try telnet to the server from your machine.
One more thing to check would be port the server is configured for if its not the default one you will have to add the port as 132.186.127.169,XXX

Servername in the connection string is wrong. and also since there are no dynamic values you don't need string concatenation. Change it to:
string constring = "Data Source=132.186.127.169;
Initial Catalog=CadPool1;
Integrated Security=True";