I have created a Windows Forms application that is supposed to add a new record into a database. Now, it adds it successfully and the new data can be used... but when I close the application and start it again, the application acts as if nothing has changed.
The database was created in SQL Server and the application uses the .mdf file it generated.
Here is the method:
private void btnUnos_Click(object sender, EventArgs e)
{
//create an instance of the row to be inserted
PIScarinaDataSet.OsobaRow novaOsoba;
novaOsoba = pIScarinaDataSet.Osoba.NewOsobaRow();
//fill the attributes
novaOsoba.Ime = txtImeOsobe.Text;
novaOsoba.Drzavnost = dobijDrzavu();
novaOsoba.Predstavlja = dobijPredstavnika();
//insert into the database
this.Validate();
this.pIScarinaDataSet.Osoba.Rows.Add(novaOsoba);
this.osobaTableAdapter1.Update(this.pIScarinaDataSet.Osoba);
this.osobaBindingSource1.EndEdit();
}
Since this is what helped you, I will make it an answer:
[S]ince you're using the .MDF created by SQL Server, you need to make sure the "Copy to Output Directory" property on the file is set to "Copy if newer" in Visual Studio. (Or, "Do not copy" if you're going to manually put it in the correct directory.) That is, if you're actually saving the data and this is the issue.
You didn't show us the crucial part - the connection string of your application - but I'm guessing that it will contain something like AttachDbFileName=yourdatabase.mdf somewhere in there.
The whole User Instance and 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...
Related
When I try to add an item into the database, after running the app the data won't be in the database for long time memory. I don't know why, the connection is good and I already checked it many times.
private void InsertIncomeBtn_Click(object sender, RoutedEventArgs e)
{
float lf = (float)Convert.ToDouble(IncomeText.Text);
MessageBox.Show(lf.ToString());
DateTime date = (DateTime)MovDatePick.SelectedDate;
Movments mv1 = new Movments();
mv1.Sum = lf;
mv1.Date = date.Date;
db.TotalAll.FirstOrDefault().CurrentSum += lf;
db.Movments.Add(mv1);
db.SaveChanges();
IncomeWin.Close();
MainWindow m = new MainWindow();
m.Show();
}
I am using VS 2017 Community and writing a WPF app.
Thank for helping.
I'm assuming (from a lot of previous questions) that you have a SQL Server database, and your connection string most likely contains an AttachDbFileName=..... entry - correct?
If so: 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. YourDatabase)
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=YourDatabase;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.
After a few years, I have returned to writing in C# and I am really struggling here - I would like to have my app to have a local SQL database. I have added Service-based database and "Database1.mdf" was added to my project. I created a table and added some data just to see if it is working but I cannot connect to it. I tried numerous connection strings with no success (Server not accessible).
Do I need to run something else in the background? I thought that I might have a local database and with .NET client I can access it, and I hoped it would work whenever I bring my application (also not requiring any SQL server running). Is that wrong?
If you don't require any SQL server, take a look at SQLite. This is lite SQL database engine. Database is just one file. C# has a great library to SQLite on NuGet: https://www.nuget.org/profiles/mistachkin
SQLite is widely used, event in Android (as a native db engine).
here is what i use to connect. it appears as a Data Connection in Server Explorer.
string con2 = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=" + Application.StartupPath + "\\jobfile_2017.mdf;Integrated Security=True;Connect Timeout=30";
when i first started working with these, i used this source 1
it works on PC's that i have nothing installed (not even office) but as i said i'd be interested to know of any shortcomings of this method
I experiencing same problem and decided to move mdf file to static c:\db directory. Connection string was changed to incorporate new file location (AttachDbFile).
But AttachDbFile has some issues also (by some reason one table in db is inaccesible and error is access denied).
So I decided to move to Sqlite. LocalDb has many issues to work with. I read good note to resolve problem: in command line stop/remove/start name of instance. But it nuissance.
Wish you good luck to work with these db files.
I need your help.. maybe it's the small task which I am not able to solve but I don't know how to search that on any search engine
I am using an .mdf file (vs 2103) in my WPF login register desktop application.. Everything is working fine, no compilation errors. I inserted some data into the .mdf file by using query in Visual Studio and then try to login through application and it's working fine. Moreover I am also able to register, i.e., insert into .mdf file from the register option of application if I use the "absolute path" of the .mdf file. Problem begins when I try to insert into .mdf file using a "relative path"... it doesn't insert data into the .mdf....I don't know why.
(this absolute path is not working. I have .mdf file in the database folder)
//connection string
connetionString = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database\Database1.mdf;Integrated Security=True";
//code
SqlCommand sqlCmd;
string sql = null;
SqlConnection sqlCnn = new SqlConnection(connetionString);
try
{
sqlCnn.Open();
sql = "insert into [NewTable] ( Name , Password ) values ('ABC' , '12345')";
sqlCmd = new SqlCommand(sql, sqlCnn);
sqlCmd.ExecuteNonQuery();
sqlCnn.Close();
MessageBox.Show("You have Been Registered");
}
catch (Exception ex)
{
MessageBox.Show("" + ex);
}
It shows the message "You have Been Registered"
but is not visible in .mdf file...
I want to ask..why is it behaving like this....and I want to use the relative path as we cant judge the client system absolute path...what mistake I am doing? how to handle this (i guess self made) issue?
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 excellent blog article Bad habits to kick: Using AttachDbFileName for more in depth explanations and tips
I have a C# winforms application, and a SQL Server .mdf database file.
I tried to use Entity Framework. It works great when retrieving data from the database, but on calling .SaveChanges() nothing happens. No error, no exception, and no changes saved.
This issue just drives me crazy. I found a bunch of questions with nearly the same issue, but neither of the answers apply to my case.
My code looks like that:
using (World_ParkingEntities context = new World_ParkingEntities())
{
client _client = context.CreateObject<client>();
_client.name = name;
_client.mobile_number = phoneNo;
_client.email = email;
context.AddToclients(_client);
context.SaveChanges();
}
My connection string:
<add name="World_ParkingEntities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\World_Parking.mdf;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" /></connectionStrings>
The whole User Instance and 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 after the context.SaveChanges(); 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. World_Parking)
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=World_Parking;Integrated Security=True
and everything else is exactly the same as before...
I have C# application which uses SQL Server R2 as its database. That database is on a separate PC by the name of SERVER. SQL Server's instance name also server.
My windows application uses DataSet to communicate with the database. Now my SQL installed PC name is change to another name, ex SERVERHP. Now all my coding works want to change my connection string. Are there any other easy way to do it ?
I am to tried to edit hosts file, but it does not work for me.
This is my coding style (http://goo.gl/FQrkp). I am using DataSet with DataAdapter with IDE designers.
I have 100 ~ 150 forms. Now I cannot compile all codings. I want to easy method to connect that SQL Server database.
I want to have a way to hide the change of the hostname of the computer
You have a couple of options:
Globally replace all server names with IP address in connection strings in the app
Globally replace all server names with the new server name in the app
Add a CNAME record to the DNS table on the server (assuming of course you're in the same network, which you are if you're using computer names)
Add an entry to the LMHOSTS file (you can add as many names as you'd like that point to the same IP)
As I understand, it is SqlConnection used to connect to database, or something like that. Why don't you use SqlConnectionStringBuilder? Then you can dinamically construct connection string you need. Also, to get list of servers, you can use SqlDataSourceEnumerator, from namespace System.Data.Sql.
It sounds like you want to have a way to hide the change of the hostname of the computer (Server/Desktop/Virtualized instance of Windows, whatever) that is running your SQL Server.
This isn't my area of expertise, but I can't think of a way to do it that only involves your application code and just the computer.
If you control the local DNS you can create a CNAME entry with the old name that "points" at the new one. Depending on how your connection strings are stored, you might have to edit them or you might not. But you won't have to worry about the location of your SQL Server changing again because you can always edit your CNAME to point at the new location.
Note for the future - not your current problem: If you continue to use MS SQL Server in particular you'll want to be careful about moving it to a computer where it isn't the default instance because then you need to put the instance name in the connection string as well, which might force you to edit all of your application web.configs and app.configs again.
Are you using Visual Studio 2012 with your development efforts? I ran into a conflict with the mini SQL db VS installs (Using Premium version) and had to modify the ConnectionStrings section of my Machine.config file to point to my SQL database. For whatever reason, VS will write references to the mini db in the Machine.Config file (for whatever version of .Net you are leveraging) throwing potetial conflicts.
The file can be found in %systemroot%\Microsoft.Net\Framework64\dot net version\Config
If you're using an x86 processor the Framework64 folder is just called 'Framework'.