connect database with dataGridView - c#

How can I connect my Trgovina.mdf with dataGridView?
I follow this tutorial, but it seems that program doesn't find my database.
Connection string looks like that:
string connString = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Klemen\documents\visual studio 2012\Projects\Trgovina\Trgovina\Trgovina.mdf;Integrated Security=True";
Everything else is the same as tutorial example.
Error string is An OLE DB Provider was not specified in the ConnectionString. An example would be, 'Provider=SQLOLEDB;'
Full code looks like this.

The tutorial you talk about in your question use an Access Database and thus uses the OleDB engine to reach and work with the database. Instead your connection string use the syntax reserved for SQLServer LocalDB.
You should change your objects to SqlConnection (instead of OleDbConnection), SqlCommand (instead of OleDbCommand) and so on...
With these changes you should be able to connect to the automatic instance of SqlServer LocalDB. The rest of the tutorial could work or not, depending on what is present in the MDF file used.

You trying to connect to database .mdf file, but you have a wrong provider.
An MDF is a Microsoft SQL Server database not a Jet Database like
Access (*.mdb). You cannot just connect to the flat file and read it.
You would need to mount the database in an instance of SQL Server.
You could install SQL Server 2005 Express
Source
Note: Just download MS SQL Server 2005 Express or later and you must use the System.Data.SqlClient instead of OLE DB to solve your problem.

Related

Local DB in Visual Studio 2015

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.

Can not connect to MySQL with VS2012

I am trying to establish connection between my application in C# and MySQL. I have downloaded .NET connector from MySql website.
I have installed MySQL server with TYPO3 winstaller, and it is running properly.
Here is my code:
MySqlConnection con = new MySqlConnection("Server=localhost:8501;Database=drogy;Uid=root;Pwd=;");
con.Open();
It says that: Unable to connect to any of the specified MySQL hosts.
In PHPMyAdmin I see host as localhost:8501. I am sure that user root has password set to NO and I am also pretty sure about the database name. How can I do this please? Thank you
you should not mention the password if maybe its should be empty means use the ' ' single quotes in you code.
And you should remove the ; in after the password like ot;Pwd=;"); you should change like ot;Pwd=");
if your not add the connector, first of all you should must add the MySQL Connector.
sample code:
"server=localhost:portno; user id=yourusername; password=yourpassword; database=yourdatabasename"
update:1
All had happend after moving database files to new location and after updating mysql server. All tables with InnoDB engine disappeared from my database. I was trying to recreate them, but mysql told me 1146: Table 'xxx' doesn't exist all the time until I had recreated my database and restarted mysql service.
I think there's a need to read about InnoDB table binaries.
click here : 1
*Pwd=;"*Required your database password
In the password field give your password and try it.. it will work

Create connection to database in VS2010 without SQL Client - dynamically

How to create connection to database in VS2010 without SQL Client dynamically?
I tried using ConnectionStringSettings and SqlConnection and I succeeded, but I'm not supposed to use SQL Client.
I'm using Massive.
You should be able to use System.Data.OleDb.OleDbConnection.
Use a connection string like this:
Provider=SQLOLEDB;Server=myServerAddress;Database=myDataBase;Uid=myUsername; Pwd=myPassword;
It might be that you just miss to reference System.Configuration in your project and consequently Massive cannot find the connection string in your app.config.
Following the instructions on github I could query my SQL Express database without any problems using Massive having a plain SqlClient connection string in my app.config.

Migrating from SQL Server CE to SQL Server database

Currently I am using SQL Server CE for persisting my data for which I am providing with a .sdf and connection string mentioned in app.config pointing to this .sdf file.
Now I want to provide user with the flexibility to have the data stored in their own SQL Server database if present at there disposal.
Now I am facing the problem of how to change the connection string at runtime if user chooses to uses its own database ?
Or if restrict them to use my predefined .mdf file how to attach that in their SQL Server ?
My recommendation would be to have 2 connection strings in the configuration file (app or web). There is a special section for them intuitively called ConnectionStrings. You can then switch between them based on other settings.
Changing connection strings dynamically is actually pretty easy to do as long as you have a place to store the new settings (ie. web or app config files). If you provide a way for them to enter the server information you can use the ConfigurationManager class to update your app/web.config.
Ado.net typically has parameters on almost any db connection object that allows you to specify the connection string as an arguement. Additionally, there are helper classes that can be used to construct the connection string on the fly like the SqlConnectionStringBuilder or EntityConnectionStringBuilder. I personally love the Entity Framework as it allows you to create the database from the model itself if it does not already exist, provided you already have the connection string.

SQL Server CE Database Connection Issues

I have an application with a database called voodoobase.sdf.
Using .NET Framework Data Provider for Microsoft SQL Server Compact 3.5
I can see it in Server Explorer and connect to it fine from there. The DB File is located in:
c:\Users\me\Documents\VisualStudio2010\Projects\testproj\voodoobase.sdf
The same named DB under Solution Explorer is said to reside at the same location.
c:\Users\me\Documents\VisualStudio2010\Projects\testproj\voodoobase.sdf
Assuming they are the same... why can my application which compiles successfully alwways crash with a connection error:
SqlConnection dbCon = new SqlConnection(Properties.Settings.Default.voodoobaseConnectionString);
dbCon.Open();
Throws an error on dbCon.Open() saying that could not get a connection to the SQL server. Let me know if further detail is required.
Do not use the SqlConnection class, but the SqlCeConnection class.

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