SQLiteConnection conn = new SQLiteConnection("Data Source=/data/bakkal.db3;");
conn.Open();
conn.Close();
I am new at programming so maybe the problem is a very dumb one, sorry for that.
I am trying to connect my project with a database which exists in the directory listed above. But the project gives an error at "conn.Open();" line which is just "unable to connect database". Database has no passwords or etc, it is just a very small database with 2 columns.
I don't think it is going to change anything but my project is a WPF application project, maybe differs.
Thanks for any help
If the database file is located in the same folder as the executable you could try this:
using (var conn = new SQLiteConnection(#"Data Source=|DataDirectory|bakkal.db3"))
{
conn.Open();
}
If it is in a subfolder:
#"|DataDirectory|data\bakkal.db3"
If not use absolute path:
#"c:\somepath\data\bakkal.db3"
Write out the location of the database completely [drive][path][databasefile]
using (SQLiteConnection connection = new SQLiteConnection(#"Data Source=c:\data\bakkal.db3"))
{
connection .Open();
}
Related
I'm new to coding. I'm attempting to access a SQL Server file through WPF / C# and I am having trouble getting in the correct string, I believe. I do not yet fully understand SQL logins, but here is the code I have now, which I believe as close to correct as I can get on my own:
string CS = #"Data Source=(LocalDB)\v11.0; Integrated Security=true; AttachDbFileName=C:\Users\Madison\source\repos\TheRealStudyBot\TheRealStudyBot\TestingData.mdf";
SqlConnection con = new SqlConnection(CS);
SqlCommand cmd = new SqlCommand("CREATE TABLE table1 (PK int, Name nvarchar(255), PRIMARY KEY *PK),);", con);
con.Open();
SqlDataReader rdr = cmd.ExecuteReader();
con.Close();
This code is under public MainWindow(), after InitializeComponent(). The file path should be correct. The database is empty. I get this exception:
Win32Exception: Unknown error (0x89c50118)
Ran it once more and I think I may have accidentally altered my debug settings because now it also provides a window stating
The solution does not contain the specified document
(along with plenty of other jargony-code-exception-results-text). I don't see where I'm going wrong. Please help!
If you are on Visual Studio 2019,
Double Click on your LocalDB which opens Server Explorer
Clicking on your database, On the properties tab shows the connection string.
Copy that & Paste on CS!
And the Normal Connection String Format For LocalDB is,
Data Source=Your_DataSource;Initial Catalog=YourDatabaseName;Integrated Security=True;Pooling=False
I developed C# Word add-in which populates some data from database file. It is working fine while I am running through Visual studio running. But if I publish it cannot connect to database.
Here is how I get data from database:
SQLiteConnection con = new SQLiteConnection(ThisAddIn.connectionString);
con.Open();
var command = con.CreateCommand();
command.CommandText =
#"
SELECT *
FROM JK
WHERE article_number = $article_number
";
command.Parameters.AddWithValue("$article_number", textFromDoc);
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
var title = reader.GetString(2);
var article = reader.GetString(3);
ResultForm resultForm = new ResultForm();
resultForm.setArticle(title, article);
resultForm.ShowDialog();
}
}
public static string connectionString = #"Data Source=E:\projects\c#\TBPWordAddin\WordAddIn1\codexes.db";
Am I doing something wrong or do I need to include file in another way? Any help will be appreciated.
Also I tried publishing using Visual studio installer and it connected to database but the add in didnot lounched on other computers.
The connection string contains an absolute path which can be changed after publishing an application. I'd suggest using a relative path instead - in that case you will be able to find the Db easily. You may check out the following threads for more information on such kind of issues:
Connection string with relative path to the database file
How to give relative path of connection string or data source in windows form application
But if I publish it cannot connect to database.
Make sure the Db path (see the connection string) corresponds to the hardcoded value in the application used.
Yes, I know that this questions has been asked at least 5-10 times in here, but I can't for the life of me get any of the methods to save the data.
The idea is to create a new row in table Companies in column Name (there is only one column) with value "asdf"`.
I've tried combinations of the following:
DatabaseDataSetTableAdapters.CompaniesTableAdapter adapter = new DatabaseDataSetTableAdapters.CompaniesTableAdapter();
DatabaseDataSet ds = new DatabaseDataSet();
adapter.Insert("asdf");
adapter.Fill(ds.Companies);
adapter.Update(ds.Companies);
ds.AcceptChanges();
ds.Companies.AddCompaniesRow("asdf");
ds.Companies.AcceptChanges();
ds.Companies.AddCompaniesRow("asdf");
ds.Companies.Rows[0]["Name"] = "asdf";
adapter.Update(ds.Companies);
I'm using C# WPF .NET 4.5.1
It does add the data, but it doesn't save it when I exit the program - I know that it adds data, because if I call this method twice it crashes, because the value is no longer unique.
Here is the DatabaseDataSetTableAdapters:
http://pastebin.com/gNsaRFD5
This did not work either:
SqlConnection myConnection = new SqlConnection(global::AliBabaMailer.Properties.Settings.Default.DatabaseConnectionString);
myConnection.Open();
SqlCommand myCommand = new SqlCommand("INSERT INTO Companies (Name) " +
"Values ('string')", myConnection);
myCommand.ExecuteNonQuery();
myConnection.Close();
Ok so your problem is the Connection String:
Properties.Settings.Default.DatabaseConnectionString
This connection string is of the form:
“Data Source=ServerName;AttachDbFilename=|DataDirectory|\DataBaseName;Integrated Security=True”
The |DataDirectory| is usually here:
C:\Users\UserName\AppData
When you save the data it is being saved to a database file at `|DataDirectory| location but when you try to view the data using Server Explorer you are trying to view from a database file which is in your project's folder, that is why If you try to save and then view the data on run time it will work fine because then you will be querying the same database you are storing your data into.
|DataDirectory|:
|DataDirectory| (enclosed in pipe symbols) is a substitution string that indicates the path to the database. It eliminates the need to hard-code the full path which leads to several problems as the full path to the database could be serialized in different places. |DataDirectory| also makes it easy to share a project and also to deploy an application.
For example, instead of having the following connection string:
"Data Source= c:\program files\MyApp\Mydb.sdf"
Using DataDirectory, you can have the following connection string:
“Data Source = |DataDirectory|\Mydb.sdf”
To set the DataDirectory property, call the AppDomain.SetData method. If you do not set the DataDirectory property, the following default rules will be applied to access the database folder:
For applications that are put in a folder on the user's computer, the database folder uses the application folder.
For applications that are running under ClickOnce, the database folder uses the specific data folder that is created.
Link
Coding Advice:
Try to dispose your Command and Connection Objects like this:
using(SqlConnection myConnection = new SqlConnection(global::AliBabaMailer.Properties.Settings.Default.DatabaseConnectionString))
using(SqlCommand myCommand = new SqlCommand("INSERT INTO Companies (Name) " + "Values ('string')", myConnection))
{
myConnection.Open();
myCommand.ExecuteNonQuery();
myConnection.Close();
}
Right, I have been tasked with developing a new application in MVC3 that unfortunately has to integrate very slightly with a classic asp web site. This won't be forever as the old site will get an update at some point, but not yet. In the mean time however the new MVC3 application will need a little bit of access to the database for the old site, which is a old MS Access .mdb whereas the new app will be using sql server 2008.
I would greatly appreciate it if someone could give me some examples of how to connect to the access db, aswell as how to execute sql queries (i am fine writing the sql, just got no idea how to execute against the database from my mvc3 app).
thanks in advance
EDIT: I've not got much experience with the old site, but it appears to use the JET adaptor if that helps! ;-)
Your question requires an answer too extensive to be given in detail
I will give you a check list of things and class to research
Define the connection string used to reach your database [see
here]
Create and open the OleDbConnection
Define your OleDbCommand and the command text to be executed
Create and use an OleDbDataReader to read your data line by line
Create and use an OleDbDataAdapter to read your data and load a
DataSet or DataTable
Now don't forget to close your connection and use parametrized query
string connectionString = Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\mydatabase.mdb;Jet OLEDB:Database Password=MyDbPassword;
public void InsertRow(string connectionString, string insertSQL)
{
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
// The insertSQL string contains a SQL statement that
// inserts a new row in the source table.
OleDbCommand command = new OleDbCommand(insertSQL);
// Set the Connection to the new OleDbConnection.
command.Connection = connection;
// Open the connection and execute the insert command.
try
{
connection.Open();
command.ExecuteNonQuery();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
// The connection is automatically closed when the
// code exits the using block.
}
}
Hello I'm trying to run a simple sql command on a DB from MS VS C# 2010 and I have encountered a error I have never seen before the relevant code is:
SqlConnection comCon = new SqlConnection(#"Data Source=C:\\Users\\George\\Desktop\\programming\\C#workspace\\Projects\\Examen\\Examen\\Companie.mdf;Initial Catalog=Proiect;Integrated Security=True");
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "UPDATE Proiect SET Buget = Buget + 500 WHERE (Buget > 0)";
cmd.Connection = comCon;
comCon.Open();
Console.WriteLine(cmd.ExecuteNonQuery().ToString());
comCon.Close();
And the error is Keyword not supported: 'data source'
The main problem is that I'm not used to creating these sqlconnections by hand so please tell me if I'm missing something.
You are using the wrong structure. To attach a database file, you need to use the following structure:
SqlConnection sqlConnection =
"Server=DatabaseServerName;AttachDbFilename=d:\Database\Database.mdf;
Database=DatabaseName; Trusted_Connection=Yes";
You need to have the right permissions on both the target file and database server to attach the databse and establish the connection.
Server=.\SQLExpress;AttachDbFilename=|DataDirectory|mydbfile.mdf;Database=dbname; Trusted_Connection=Yes;
If it's not an ASP.NET application don't use the DataDirectory syntax and just use the full c:... path.