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Data is not showing/updating in the SQLite table when the data is inserted through my C# code

Currently, I have been doing some simple coding related to SQL and C#. I have created this a registration form which will store the data, username and password, in an SQLite database. This is the code that I am currently using:
private void AddLoginInfo(string username, string password)
{
auth = new Authentication();
auth.getConnection();
using (SQLiteConnection con = new SQLiteConnection(auth.connectionstring))
{
SQLiteCommand cmd = new SQLiteCommand();
con.Open();
string que = #"INSERT INTO LoginInfo(Username, Password) VALUES (#username, #password)";
cmd.CommandText = que;
cmd.Connection = con;
cmd.Parameters.Add(new SQLiteParameter("#Username", username));
cmd.Parameters.Add(new SQLiteParameter("#Password", password));
cmd.ExecuteNonQuery();
MessageBox.Show("Account Created!");
}
}
This code currently works and does add to the correct table in the database however whenever a new user is added. The user information can be used to login but it does not show within the table, which is viewed using DB Browser for SQLite.
For example, if I create a new user; 'admin' as the username and 'password' as the password, through the form, I get the message box saying 'Account Created' and I can use that very account to login. However, if I go view that very data in the DB browser the data doesn't show even after refreshing the table.
After doing some digging, I found this and saw that they were using sqlCommand.Parameters.AddWithValue so I tried this within my code:
SQLiteCommand cmd = new SQLiteCommand(#"INSERT INTO LoginInfo(Username, Password) VALUES (#username, #password)", con);
cmd.Parameters.AddWithValue(new SQLiteParameter("#Username", txtBoxUsername.Text));
I tried this and I got a CS7036 error. Then I realised that they had not used the new SQLiteParameter() part and so I removed it cmd.Parameters.AddWithValue("#Username", txtBoxUsername.Text); and tried again but it still wouldn't update in the table but the data could still be used to log in.
I have also found a similar post but no one had answered it.
Now I don't know what to do, so I am asking for your help.

I figured out what was the problem; I was checking the database that was stored in the solution but what I should have checked is the database stored in the ...\bin\debug folder. The database within the folder shows the added data.

Are you retrieving the db file from another system? i.e. Android Emulator or a network location?
Are there any other files in the folder, you are specifically looking for a filename that contains '-wal'. Additional information on SQLite Wal format
the data is actually contained in this other file. DB Browser knows to look for this file. However, if you are downloading the db to your system before you take a look, you are probably not downloading the -wal file as well.
Depending on how you are configuring your SQLite db, the limit by default for checkpoint threshold is 1kb. Until the checkpoint is triggered, the data doesn't get transferred to the main db file. There are ways to manually trigger the checkpoint, see the link I have included above.

Unspecified Error when trying to ExecuteReader on SQL Server CE

I had implemented a database storage on my app for Windows Mobile 6.5 using SQL Server CE.
Had managed to install the SQL Server CE CAB file on the device (Motorola MC65).
Managed to create database file, and create tables. Insert also can be executed.
However when I try to run ExecuteReader() to read records, I hit the following error:
Error Code: 80004005
Message : Unspecified error
Minor Err.: 25534
Source : SQL Server Compact ADO.NET Data Provider
No idea why this is happening. Since insert can be executed I thought this should not be a connection or privilege issue.
The reading code is as below:
openConnection();
SqlCeCommand cmd = conn.CreateCommand();
cmd.CommandText = "SELECT NAME FROM GROUP_INFO ORDER BY NAME ";
SqlCeDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
string groupName = reader.GetString(0);
listGroup.Add(groupName);
}
The exception is thrown on the line where cmd.ExecuteReader() is executing.
Any pointers are appreciated. Thanks.

Implement proper error handling for SqlCeExceptions! The error is documented here https://technet.microsoft.com/en-us/library/ms172350(v=sql.110).aspx
Large objects (ntext and image) cannot be used in ORDER BY clauses.
Maybe you should redefine the column as nvarchar(4000) (it is currently ntext), or rephrase the query using:
ORDER BY CAST(Name as nvarchar(4000))
But this will cause a table scan

Copy a whole table from a SQL Server CE database to another

I'm developing a C# application and I want to copy a whole table from a SQL Server CE database to another programmatically. I know I can use this command in SQL Server, but I'm not sure how to use two database connections in one query in C#.
Select * into DestinationDB.dbo.tableName from SourceDB.dbo.SourceTable
Thanks in advance.

You wouldn't do it the same way as in SQL Server because there's no single server that manages both databases. Your app is the only thing that links the two databases so the the data has to go through your app. You're trying to do it the wrong way and that's why you can't find a solution: you're looking for the wrong thing.
There are examples of this out there. I know, because I've written more than one myself. You simply need to use a data adapter to populate a DataTable from the first database and then a data adapter to save the contents of that DataTable to the second database. If the data sources are the same type then you can even use just one data adapter because the SelectCommand and InsertCommand can have different connections.
using (var adapter = new SqlDataAdapter("SELECT statement here", "source connection string here"))
using (var destinationConnection = new SqlConnection("destination connection string here"))
using (var insertCommand = new SqlCommand("INSERT statement here", destinationConnection))
{
// Add parameters to insertCommand here.
adapter.InsertCommand = insertCommand;
// Leave the RowState of all DataRows as Added so they are ready to be inserted.
adapter.AcceptChangesDuringFill = false;
var table = new DataTable();
// Retrieve data from source and save to destination.
adapter.Fill(table);
adapter.Update(table);
}
That example uses SqlClient but it works the same for any provider, including SqlServerCe.

How to insert data into a Microsoft Access Database?

I'm trying to insert data into a Microsoft Access Database.
I inserted data into the Access database, but the first and second time are the only times that show the data I inserted. When I rebuild my application, the data I inserted is gone. I don't know where they go and not show. I use C# with the .NET framework to develop. Here's the relevant part of the code:
OleDbConnection con = new OleDbConnection(ConfigurationManager.ConnectionStrings["Constr"].ConnectionString);
OleDbCommand com = new OleDbCommand();
com.Connection = con;
com.CommandText = "Insert into Language(English,Type,Thai) values(#eng,#type,#thai)";
com.Parameters.AddWithValue("#eng", english);
com.Parameters.AddWithValue("#type", type);
com.Parameters.AddWithValue("#thai", thai);
con.Open();
com.ExecuteNonQuery();
I wrote that code, but I think it is strange. It doesn't show any errors or exceptions, but my data is not inserted correctly. Is this the correct way to insert data? If so, why it it not getting inserted?

When I rebuild my application, the data I inserted is gone
I suspect your database is being overwritten when the application is rebuilt.
This can happen, for example, if your application contains an MDB file that is copied to the output directory on build, and is used from the output directory.

I think Language should be a reserve word and you should wrap it in [] brackets.
Also consider wrapping the code in using blocks, like
using (OleDbConnection con = new OleDbConnection(...))
{
using (OleDbCommand com = new OleDbCommand(sqlString, con))
{
//code
}
}
Other than this [possible issue with table name and that you are not closing your connection], I don't see anything wrong with the code.

You define parameters for the query, but I don't see anywhere those parameters are bound to actual data...
Try some simple tests that replace the variables you're passing in as parameters with actual values, so you can isolate the problem:
In other words, replace this:
com.Parameters.AddWithValue("#eng", english);
com.Parameters.AddWithValue("#type", type);
com.Parameters.AddWithValue("#thai", thai);
With something like this:
//I don't know the data types of your fields, so I'm guessing
com.Parameters.AddWithValue("#eng", "Test1");
com.Parameters.AddWithValue("#type", myEnum.Latin);
com.Parameters.AddWithValue("#thai", "Test1a");
If that works, then your problem probably lies with the english, type, and thai variables and you'll want to make sure they're getting the data you think they should be getting.

May be ur connection string not correct you can it by using .udl file
just follow the link
http://www.gotknowhow.com/articles/test-a-database-connection-string-using-notepad
You can also check the code shown below
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Users\\ruby\\Desktop\\screenShots\\ruby.mdb;Persist Security Info=False");
con.Open();
OleDbCommand cmd = new OleDbCommand("insert into raj(Name,Roll) values('XYZ',12);",con);
cmd.ExecuteNonQuery();

SQL 'Execute As' Login Command and Linq to SQL

I am trying to execute a sql query as another login using the 'Execute As' command. I am using Linq to SQL, so I've generated a Data Context class and I am using the ExecuteQuery method to run the 'Execute As' SQL command. I then call a Linq to SQL command that is successful. However, every subsequent query fails with the following error:
A severe error occurred on the current command. The results, if any, should be discarded.
Here is the code snippet that I have tried:
SummaryDataContext summary = new SummaryDataContext();
summary.ExecuteQuery<CustomPostResult>(#"Execute as Login='Titan\Administrator'");
var test = summary.Customers.First();
var test2 = summary.Products.ToList();
No matter what query I run on the second query I receive the error message from above. Any help would be appreciated.

I managed to get around this issue in my application by executing the query using ADO.NET classes.
SqlCommand cmd = new SqlCommand("EXECUTE AS USER = 'operator'");
cmd.Connection = dc.Connection as SqlConnection;
cmd.Connection.Open();
cmd.ExecuteNonQuery();
// do the rest of the queries using linq to sql

You may have already ruled this out, but one possible work around would be to simply create the data context with a different connection string.
To edit the connection string, you can set the DataContext.Connection.ConnectionString property. I've done it before in the partial method OnCreated(), which gets called when the data context gets created. I haven't tested but I think you could also do:
YourDataContext dc = new YourDataContext();
dc.Connection.ConnectionString = "connection string here";
Here's an article that describes this as well - http://www.mha.dk/post/Setting-DataContext-Connection-String-at-runtime.aspx

I was having a similar issue and by looking at ruskey's answer I was able to Execute as User but noticed that I was getting errors when running other queries after that. It was due to the missing Revert. So for anyone having a similar issue this is how the code looks like.
SqlCommand cmd = new SqlCommand("EXECUTE AS USER = 'domain\\user';");
OSSDBDataContext dc = new OSSDBDataContext();
cmd.Connection = dc.Connection as SqlConnection;
cmd.Connection.Open();
cmd.ExecuteNonQuery();
//Execute stored procedure code goes here
SqlCommand cmd2 = new SqlCommand("REVERT;");
cmd2.Connection = dc.Connection as SqlConnection;
cmd2.ExecuteNonQuery();