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unable to insert data in sql database with c# even no error accur

hy I want to insert new record in my database but am unable to do this even code is fully error free, I added following code in my button click event
here is my code
SqlConnection con= new SqlConnection("Data Source=.;Initial Catalog=Sample;Integrated Security=true;");
SqlCommand cmd;
SqlDataAdapter adapt;
private void btn_Update_Click(object sender, EventArgs e)
{
string query="insert into users(Name,Password)values('ubaid','ali')";
cmd = new SqlCommand(query, con);
con.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Record Updated Successfully");
con.Close();
}
I mean insert query is not updating my database, even when I execute my query it return 2 not 0 which means query applied successfully,

not really an answer but the steps you need to take to see whats going on, so we can help you are a bit longer...
you will need to execute the following query, once in your sql management studio, and once in your program ... i suspect the result being different in both cases
select ##SERVERNAME, ##SERVICENAME, db_name(), SCHEMA_NAME()
on the code side please use this:
private void btn_Update_Click(object sender, EventArgs e)
{
// string query="insert into users(Name,Password)values('ubaid','ali')";
// cmd = new SqlCommand(query, con);
// con.Open();
// cmd.ExecuteNonQuery();
// MessageBox.Show("Record Updated Successfully");
// con.Close();
string query="select ##SERVERNAME, ##SERVICENAME, db_name(), SCHEMA_NAME()";
cmd = new SqlCommand(query, con);
con.Open();
using(var rdr = cmd.ExecuteReader())
{
rdr.read();
MessageBox.Show($"{rdr.GetString(0)}, {rdr.GetString(1)}, {rdr.GetString(2)}, {rdr.GetString(3)} ");
}
con.Close();
}
the result should show the name of the server, its instance name, the name of your DB and of the default schema you are using in both cases
example result for my testmachine would look like this:
srv9, MSSQLSERVER, testdb, dbo
expectation in your case:
you will get 2 different results which means that your sql management studio, where you are trying to check if your code did the right thing, is using a different server, instance, database or schema
with the provided information it will be possible to change the used connectionstring so both your clients work on the same database...

Cant read from SQL Server database in C#

I am currently working on a college assignment in which I am having trouble reading data from a SQL Server database. I'm attempting to read the Dentist Name column and then add these names to a combobox.
However when I input the column name it shows an error.
My table is called dentistInfo with columns Dentist ID, Dentist Name, Dentist Surname, DOB and Gender.
Eventually when I get to the reading done correctly I will then hopefully be able to populate their details when the names are selected from the combobox.
public partial class Dentist_Info : Form
{
Surgery mySurgery = new Surgery();
private SqlConnection conn;
private SqlCommand cmd;
private SqlDataAdapter da;
Surgery _formsSurgery;
public Dentist_Info(Surgery SurgeryToDisplay)
{
_formsSurgery = SurgeryToDisplay;
}
public void FillCombo()
{
SqlConnection conn = new SqlConnection(#"Data Source = GGJG; Initial Catalog = DentistDB; Integrated Security = True");
SqlCommand SelectCommand = new SqlCommand("SELECT * FROM DentistInfo", conn);
SqlDataReader myreader;
conn.Open();
try
{
myreader = SelectCommand.ExecuteReader();
while (myreader.Read())
{
string dname = myreader.GetString("Dentist Name");
comboBox1.Items.Add(dname);
}
conn.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message, ex);
}
finally
{
if (conn != null)
{
conn.Close();
}
}
}

Pro-tip: If you want to ask about an error, post the error.
In any case, the problem is easy to spot in this case. There's no overload of GetString that accepts a string as an argument - you can only use the column index.
So either you need to pass the column index (myreader.GetOrdinal("Dentist Name")) or you need to use the indexer ((string)myreader["Dentist Name"]). In either case, make sure to handle possible NULL values properly - data reader simply throws an exception if you try to read an SQL NULL value.
As an aside, your try...catch can be simplified (and more useful):
When you want to rethrow an exception, use throw; (no "argument"). Wrap the exception only if you have some information to add.
The catch clause isn't required. It seems that you're only using it for the finally - it's perfectly fine to just use try...finally without the catch.
conn can never be null in the finally clause - your try isn't long enough.
For a pattern like this, you want to use using instead of try...finally anyway. You should also use using for the data reader.

Try this: I recommend you putting [] in the Dentist Name since it has a space between the two words, which might cause you the error, or change the name from the Database to DentistName
public void FillCombo()
{
SqlConnection conn = new SqlConnection(#"Data Source = GGJG; Initial Catalog = DentistDB; Integrated Security = True");
SqlCommand SelectCommand = new SqlCommand("SELECT * FROM DentistInfo", conn);
conn.Open();
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(SelectCommand);
da.fill(ds);
foreach(DataRow dr in ds.Tables[0].Rows)
{
comboBox1.Items.Add(dr["[Dentist Name]"].ToString());
}
conn.Close();
}
As per addition instead of using conn.Open() and conn.Close(), as the answer of the first user you can surround the connection inside a using like so:
using(SqlConnection conn = new SqlConnection(#"Data Source = GGJG; Initial Catalog = DentistDB; Integrated Security = True"))
{
//your codes here no need for conn.Open() and conn.Close()
}

Update existing database entries C# VS2010

I'm using Visual Studio 2010 to create a Win Form in c#. It has a handful of Comboboxes, and textboxes that the user can fill out and then submit to an Access DB. My issue comes in when I try to update existing entries. I load an existing entry, make my changes and click update. I do not get any system errors, my connection to the DB is successful, but no changes are actually made to the data. Am I completely missing something? Thanks in advance for any help or insight.
Here is the code for the update button:
private void updateButton_Click_1(object sender, EventArgs e)
{
{
OleDbConnection conn = new OleDbConnection();
conn.ConnectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\servicereq1.mdb";
OleDbCommand cmd = new OleDbCommand("UPDATE servicereq SET DateLogged = #datelogged, LoggedBy = #loggedby, Function = #function, [Other Impacts] = #summary, Account = #earningsaccount, [From] = #from, [To] = #to, Description = #description, Fixer = #fixer, [Time Estimate] = #timeestimate, [Actual Start] = #actualstart, [Actual Finish] = #actualfinish, [Actual Time] = #actualtime, [Programs/Forms] = #programsforms, Comments = #comments, [Retest Date] = #requestdate, Tester = #tester, Status = #status, [Problem In Environment] = #problemfoundin, [Code In Environment] = #codein WHERE (ServiceRequestNumber = #servreq)");
cmd.Connection = conn;
conn.Open();
if (conn.State == ConnectionState.Open)
{
cmd.Parameters.AddWithValue("#servreq", serviceRequestNumberTextBox.Text);
cmd.Parameters.AddWithValue("#datelogged", dateLoggedTextBox.Text);
cmd.Parameters.AddWithValue("#loggedby", loggedByComboBox.Text);
cmd.Parameters.AddWithValue("#problemfoundin", problem_In_EnvironmentComboBox.Text);
cmd.Parameters.AddWithValue("#function", functionTextBox.Text);
cmd.Parameters.AddWithValue("#summary", other_ImpactsTextBox.Text);
cmd.Parameters.AddWithValue("#earningsaccount", accountTextBox.Text);
cmd.Parameters.AddWithValue("#from", fromTextBox.Text);
cmd.Parameters.AddWithValue("#to", toTextBox.Text);
cmd.Parameters.AddWithValue("#status", statusComboBox.Text);
cmd.Parameters.AddWithValue("#description", descriptionTextBox.Text);
cmd.Parameters.AddWithValue("#fixer", fixerComboBox.Text);
cmd.Parameters.AddWithValue("#codein", code_In_EnvironmentComboBox.Text);
cmd.Parameters.AddWithValue("#programsforms", programs_FormsTextBox.Text);
cmd.Parameters.AddWithValue("#timeestimate", time_EstimateTextBox.Text);
cmd.Parameters.AddWithValue("#actualstart", actual_StartTextBox.Text);
cmd.Parameters.AddWithValue("#actualfinish", actual_FinishTextBox.Text);
cmd.Parameters.AddWithValue("#actualtime", actual_TimeTextBox.Text);
cmd.Parameters.AddWithValue("#requestdate", retest_DateTextBox.Text);
cmd.Parameters.AddWithValue("#tester", testerComboBox.Text);
cmd.Parameters.AddWithValue("#comments", commentsTextBox.Text);
try
{
cmd.ExecuteNonQuery();
MessageBox.Show("Form Updated Successfully");
conn.Close();
}
catch (OleDbException ex)
{
MessageBox.Show(ex.Message);
conn.Close();
}
}
else
{
MessageBox.Show("Connection Failed");
}
}
}

You shouldn't put your database parameters within quotes - they are evaluated as plain text instead of parameters if you do. There is no row where ServiceRequestNumber equals the literal string '#servreq', so nothing is updated.
Also, DataCommands don't pull in local variables as parameters - they must be explicitly added to the DataCommand object (cmd in this case). The reason you aren't getting any errors when you remove your parameter-adding code is because, as stated above, the query doesn't expect any parameters.
Also, the way parameters are being added in the code you removed is strange to say the least. This is much more normal, and significantly easier to read:
cmd.Paramaters.AddWithValue("#paramName", paramData);
//or
cmd.Parameters.Add(new OleDbParameter("#paramName", paramData));

After spending a little more time editing and moving code around, I stumbled on the fact that your parameters must be in the same order in the query as they are when you bind values to them. After making syntactical changes suggested by JoFlash Studios and putting my parameters in the correct order, I was able to make edits to existing data in my form.

C#: SQL can't execute the reading

I've ordered SQL Server from Somee. I want to use this SQL Server for my windows form. Somehow, i'm not sure, but whenever i execute the login query what i've found, it will have an unhandled exeption.
private void log_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = "workstation id=wbhandler.mssql.somee.com;packet size=4096;user id=acc;pwd=pw;data source=wbhandler.mssql.somee.com;persist security info=False;initial catalog=wbhandler";
con.Open();
string felh = username.Text;
string jelsz = password.Text;
string query = "SELECT * FROM accounts WHERE account=#felhasznalo AND password=#jelszó";
SqlCommand cmd = new SqlCommand(query, con);
cmd.Parameters.Add(new SqlParameter("#felhasznalo", felh));
cmd.Parameters.Add(new SqlParameter("#jelszó", jelsz));
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows == true )
{
MessageBox.Show("Succes");
}
else
{
MessageBox.Show("Failed");
}
}
I thought that the adress is wrong, but then i found on the website the connection string, and now i don't really know.
I'm thinking what's the problem is.
I have 3 schemes in the sql:
dbo, acc, guest.
I first created a table in dbo, then in acc. Now in both of it. But it doesn't execute the SqlDataReader dr = cmd.ExecuteReader();, sadly. Like i said, it has unhandled exeption. Any solution? Any ideas?
(the acc scheme is an example what i created in somee, so it doesn't exist, it's fake)
I also tried this way:
using (var dr = cmd.ExecuteReader())
{
if (dr.HasRows)
{
MessageBox.Show("Sikeres Login!");
}
else
{
MessageBox.Show("Sikertelen Login");
}
}
The problem is always the ExecuteReader()

Try the SqlParameterCollection.AddWithValue Method instead:
cmd.Parameters.AddWithValue("#felhasznalo", felh);
cmd.Parameters.AddWithValue("#jelszó", jelsz);
I will also recommend that you use using statements on your SQL objects to ensure that the unmanaged resources they consume are freed when they are no longer needed. You can read more on the using statement from here.
Another thing that I can suggest is adding Charset=utf8; to your connection string.

error in connecting combox to textbox with database

i am working on C# .net platform
i wanted to connect my combox to my text box
this is code done by me but it is give me error
private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
{
panel1.Visible = true;
string sql;
SqlConnection cn = new SqlConnection();
cn.ConnectionString = "Data Source=CJ\SQLEXPRESS;Initial Catalog=elligiblity;Persist Security Info=True;User ID=sa;Password=123";
cn.Open();
sql = "SELECT inst_name FROM institude WHERE(inst_id="+comboBox2.SelectedItem+")";
SqlCommand cmd = new SqlCommand(sql,cn);
SqlDataReader myReader = cmd.ExecuteReader();
while(myReader.Read())
{
textBox2.Text = myReader["inst_name"].ToString();
}
myReader.Close();
cn.Close();
The multi-part identifier "System.Data.DataRowView" could not be bound.
on this line of the code
SqlDataReader myReader = cmd.ExecuteReader();

As well as that problem there are a few issues with your code that you might want to bear in mind.
Firstly, if there is an error between opening and closing the connection (as indeed there was) then you're probably going to leave connections open. Eventually this will choke your site. Use
using (SqlConnection cn = new SqlConnection())
{
}
when you're out of the scope of the using statement the connection will be closed and disposed of.
Also, you probably want to parameterize your query (for reasons both of security and efficiency), so that it is
sql = "SELECT inst_name FROM institude WHERE(inst_id=#inst_id)";
Then add that parameter to your command object and set its value to your combo box selected item value.

You want
comboBox2.SelectedValue
or
comboxBox2.SelectedItem.ToString()
then but I'd look at using parameters instead as that's not a very good way of creating a SQL string.
Also, do you realise that if you return more than one result your textbox2 will only show the last result as its text will get over-ridden with each result as its read?

First of all check the binding of dropdown. If you are binding datasource with ID and Text something like this combobox2.DisplayMember ="Name"; combobox2.ValueMember ="ID". After that you have to check for the parameter to be used in your query if its text then try combobox2.text else if you are selecting on the basis of id use int.parse(combobox2.selectedvalue) or simply combobox2.selectedvalue if your id is alphanumeric.