How do I refer to SQL Server database with SqlDataAdapter - sql

Question

I'm new to C# and I'm learning it by following a tutorial.
I've created a SQL Server database (Database1.sdf) with one table and few columns by clicking "Add New Item" on my project.
SqlConnection conn = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=??????;Integrated Security=True;Connect Timeout=30;User Instance=True");
DataTable dt = new DataTable();
SqlDataAdapter SDA = new SqlDataAdapter("SELECT * FROM Database1 WHERE Titel like " + int.Parse(textBox1.Text), conn);
SDA.Fill(dt);
dataGridView1.DataSource = dt;
As you see the "???" part is where I'm stuck. I tried using the path of the database
C:\Users\1\Documents\Visual Studio 2010\Projects\Opdracht0\Opdracht0\Database1.sdf
But that is not working. When I run it, I get:
Input string was not in a correct format.
and this line is red:
SqlDataAdapter SDA = new SqlDataAdapter("SELECT * FROM Database1 WHERE Titel like" + int.Parse(textBox1.Text), conn);
As you can see it's a simple SQL statement but even that won't work.
Any tips are appreciated!

Answer 1

Your main problem is you're mixing two incompatible types of databases:
your database1.sdf file is a SQL Server Compact Edition database file
your SqlConnection and SqlCommand however are used for full-fledged SQL Server (Express) versions - and those are NOT compatible with SQL Server Compact!
So either you need to
keep using your SQL Server Compact database (database1.sdf) - but in that case, you need to use SqlCeConnection and SqlCeCommand and those commands
OR THEN:
you switch to a real SQL Server (Express, Standard, Enterprise) and in that case you can use SqlConnection and SqlCommand

Answer 2

To connect to MS SQL Server database from C#.NET, you need to create a connection string such as below:
private SqlConnection connection;
private string connectionString =
#"Server=(local);Database=Embedding_SQL_Test;User ID=sa;Password=123";
connection = new SqlConnection( connectionString );
Next, you use the SqlConnection object created above to create a 'SqlCommand', as shown below:
SqlCommand cmd = new SqlCommand( "select * from Customer where CustomerID = #Cid", connection);
The SQL query shown here can be replaced by a SELECT, INSERT, UPDATE queries etc.
Next to execute the SQL queries in the database, you use the following methods:
ExecuteReader - to execute SELECT queries
ExecuteNonQuery - to execute INSERT, DELETE, UPDATE, and SET statements.
This is a very short description of how to connect to SQL Server database from C# and execute SQL queries in the database.
For details about the connection string, the methods and their parameters check the following link: ( http://www.shahriarnk.com/embedding-sql-c-sharp-java-shahriar/ )
Here you will also find details about how to pass parameters to the SQL queries as well as calling stored procedures and much more.

Answer 3

Here's how I would go about it. I would go to MSDN and type SqlConnection into the search box. After poking around a bit (because they've deep-sixed my favorite connection string examples), I'd find something like this which has some examples like:
Persist Security Info=False;Integrated Security=true;Initial Catalog=Northwind;server=(local)
Data Source=MSSQL1;Initial Catalog=AdventureWorks;Integrated Security=true;
Usually, the server name is the same as the Computer's name, though SQL Express may do this differently. Or, (local) may work here. These connection strings will log into SQL Server with the user's Windows credentials. For a web application the actual user may depend on whether impersonation is used, etc. (And, yes, the connection string should go into the web.config so it can be updated without recompiling the app. If this is a web app.)
At any rate, if this doesn't work for you, you can use the same search strategy to find other connection string examples on MSDN or Google.