I'm working on Windows CE application, I was trying to connect to server database from the device and fetch some information from db on button click, below is the code I tried,
SqlConnection conn = new SqlConnection("Data Source=192.168.0.0;Initial Catalog=DashReport;Integrated Security=SSPI; User ID=SA;Password=Admin#123;");
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "SELECT STORE, YEAR,DATE FROM TOPSALES WHERE MONTH = " + txtcode.Text + ";";
// cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
conn.Open();
using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
sda.Fill(dt);
if (dt.Rows.Count > 0)
{
gvDataGrid.DataSource = dt;
}
else
{
MessageBox.Show("No data found");
}
}
conn.Close();
but while running the application I'm getting a SqlException. It seems there is something wrong with the connection string. What is the right method to do it?
You cannot have both the integrated security and specify a specific user id and password at the same time. Since you have the Integrated Security=SSPI;, that will take precedence and your connection tries to connect with the currently logged in Windows user.
Most likely, from a Windows CE device, you want to use the specific User I
string connStr = "Data Source=192.168.0.0;Initial Catalog=DashReport;User ID=SA;Password=Admin#123;"
SqlConnection conn = new SqlConnection(connStr);
And another word of caution from long time SQL Server users, admins, and programmers: you should NEVER EVER use the built-in sa account! Just don't do it - use another account (possibly one you create specifically for this application).
Have you tried using the Server Explorer of Visual Studio, then connect to the database, get the Connection String via Properties Window, and use it as your connection string?
Just some kind of assurance that your connection to the database is the same as your code.
Related
I'm using Sql Server 2017 and Visual Studio 2017. I transferred my database from my PC to my friend's laptop using Generate Scripts. I use the following code in my friend's laptop when trying to connect to said database in the laptop:
using (SqlConnection sqlCon = new SqlConnection(#"Data Source = (local); Initial Catalog = PresentasiDB; Integrated Security = True; Trusted_Connection = True;"))
{
DataTable orderTable = new DataTable();
SqlDataAdapter sqlda;
string insertOrder = "INSERT INTO \"Order\" DEFAULT VALUES";
using (SqlCommand newOrder = new SqlCommand(insertOrder, sqlCon))
{
sqlCon.Open();
newOrder.ExecuteNonQuery();
}
sqlda = new SqlDataAdapter("SELECT TOP 1 * FROM \"Order\" ORDER BY OrderID DESC", sqlCon);
sqlda.Fill(orderTable);
orderID = Convert.ToInt32(orderTable.Rows[0][0]);
}
However, this failed. The failure occurred in the sqlCon.Open() part. I've tried using SQL Server login Authentication and Windows Authentication. Both failed. Someone, please help me.
In the data source you need to specify server name you use to connect to sql server.
As shown in the screen the datasource here is "gaurav.goel
Try your connecting string something like this (for sa login)
string connstr = userid=sa;password=sapassword;server=localhost,1433;database=PresentasiDB;Trusted_Connection=no
To test it did you try entering the server as 'localhost' from management studio?
I want to create a program for my school, handling marks and certificates.
To save the data I have to use a "local" network shared database-file, because we are using Citrix and there is no possibility to setup an seperate SQL-Server.
I tried it with localdb v11 with the following code:
string connectionString = #"Data Source=(LocalDB)\v11.0; AttachDbFilename=D:\_prog\TestNoten\TestNoten\bin\Debug\Database1.mdf; Integrated Security=True;Connect Timeout=3;";
SqlConnection connection = new SqlConnection(connectionString);
string sql = "INSERT INTO test(name) VALUES('lal')";
SqlCommand cmd = new SqlCommand(sql, connection);
connection.Open();
cmd.ExecuteNonQuery();
connection.Close();
DataTable table = new DataTable();
SqlDataAdapter adp = new SqlDataAdapter("Select * from test", connection);
connection.Open();
adp.Fill(table);
MessageBox.Show(table.Rows[0][1].ToString());
The MessageBox says "lal", but when I restart the program with "lala" instead of "lal", it will show "lala" and not the expected "lal".
So when closing the program, the database won't be saved correctly. I also opened the file over VSs Data Connections, and the testing table is empty.
Is there something I missed?
I want to built a connection to a SQL Server database with a SELECT command.
The connection is ok but I get a error if I make a error. I want to get the Select values to a DataTable.
This I get if I try this:
The SELECT-Perssision was denied for UserApplicationRequests-Objekt, DB_CM0-Datenbank, dbo-Schema.
I use a Login Dialog in my application for building the connection string. In this form:
user id=[username];password=[password];server=[servername];Trusted_Connection=yes;database=DB_CM0
And here is my code for the SELECT command.
public DataTable GetDataTable(string sql)
{
using (con = new SqlConnection(connectionstring))
{
try
{
SqlCommand command = new SqlCommand(sql, con);
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataTable tb = new DataTable();
adapter.Fill(tb);
con.Open();
command.ExecuteReader();
return tb;
}
catch (Exception)
{
return null;
}
}
}
My SQL command:
string sql = "SELECT * FROM [DB_CM0].[dbo].[UserApplicationRequests]";
its happening because of security issue..below steps might help you
Open SQL Server Management studio
Navigate to the database 'CNET_85731' >> Security >> Users
Right click on the one which you are using in your code
And finally, just uncheck 'db_denydatareader' inside "Database Role
membership" section.
Your connection string uses the sql authentication login method and integrated security login method simultaneously... Windows integrated security will have the priority in this case and attempt to use your windows user permissions to interact with the database... maybe this is not the behaviour you intended.
I want to get into developing applications that use databases. I am fairly experienced (as an amateur) at web based database utilization (mysql, pdo, mssql with php and old style asp) so my SQL knowledge is fairly good.
Things I have done already..
Create forms application
Add four text boxes (first name, last name, email, phone)
Added a datagrid control
Created a database connection using 'Microsoft SQL Server Database File (SqlClient)'
Created a table with fields corresponding to the four text boxes.
What I want to be able to do now is, when a button is clicked, the contents of the four edit boxes are inserted using SQL. I don't want to use any 'wrapper' code that hides the SQL from me. I want to use my experience with SQL as much as possible.
So I guess what I am asking is how do I now write the necessary code to run an SQL query to insert that data. I don't need to know the SQL code obviously, just the c# code to use the 'local database file' connection to run the SQL query.
An aside question might be - is there a better/simpler way of doing this than using the 'Microsoft SQL Server Database File' connection type (I have used it because it looks like it's a way to do it without having to set up an entire sql server)
The below is inserting data using parameters which I believe is a better approach:
var insertSQL = "INSERT INTO yourTable (firstName, lastName, email, phone) VALUES (firstName, lastName, email, phone)";
string connectionString = "Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI; User ID=userid;Password=pwd;"
using (var cn = new SqlCeConnection(connectionString))
using (var cmd = new SqlCeCommand(insertSQL, cn))
{
cn.Open();
cmd.Parameters.Add("firstName", SqlDbType.NVarChar);
cmd.Parameters.Add("lastName", SqlDbType.NVarChar);
cmd.Parameters.Add("email", SqlDbType.NVarChar);
cmd.Parameters.Add("phone", SqlDbType.NVarChar);
cmd.Parameters["firstName"].Value = firstName;
cmd.Parameters["lastName"].Value = lastName;
cmd.Parameters["email"].Value = email;
cmd.Parameters["phone"].Value = phone;
cmd.ExecuteNonQuery();
}
This is selecting data from database and populating datagridview:
var dt = new DataTable();
string connectionString = "Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI; User ID=userid;Password=pwd;"
using (var cn = new SqlCeConnection(connectionString )
using (var cmd = new SqlCeCommand("Select * From yourTable", cn))
{
cn.Open();
using (var reader = cmd.ExecuteReader())
{
dt.Load(reader);
//resize the DataGridView columns to fit the newly loaded content.
yourDataGridView.AutoSize = true; yourDataGridView.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCells);
//bind the data to the grid
yourDataGridView.DataSource = dt;
}
}
This first example is an over view based upon how I think it will be easier to understand but this is not a recommended approach due to vulnerability to SQL injection (a better approach further down). However, I feel it is easier to understand.
private void InsertToSql(string wordToInsert)
{
string connectionString = Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI; User ID=myDomain\myUsername;Password=myPassword;
string queryString = "INSERT INTO table_name (column1) VALUES (" + wordToInsert + ")"; //update as you feel fit of course for insert/update etc
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open()
SqlDataAdapter adapter = new SqlDataAdapter();
SqlCommand command = new SqlCommand(queryString, connection);
command.ExecuteNonQuery();
connection.Close();
}
}
I would also suggest wrapping it in a try/catch block to ensure the connection closes if it errors.
I am not able to test this but I think it is OK!
Again don't do the above in live as it allows SQL injection - use parameters instead. However, it may be argued it is easier to do the above if you come from PHP background (just to get comfortable).
This uses parameters:
public void Insert(string customerName)
{
try
{
string connectionString = Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI; User ID=myDomain\myUsername;Password=myPassword;
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
connection.Open() SqlCommand command = new SqlCommand( "INSERT INTO Customers (CustomerName" + "VALUES (#Name)", connection);
command.Parameters.Add("#Name", SqlDbType.NChar, 50, " + customerName +");
command.ExecuteNonQuery();
connection.Close();
}
catch()
{
//Logic in here
}
finally()
{
if(con.State == ConnectionState.Open)
{
connection.Close();
}
}
}
And then you just change the SQL string to select or add!
When I tried to add a connection it is showing the following error as shown in the attachment. “Unable to open the physical file. Access is Denied” .
When I searched about it, it suggest for adding the SQL Server’s account to the folder. Then, using the following query I found that the account is “LocalSystem”. When I tried to add “LocalSystem” to ACL of the folder, such an account is not available. How do we resolve it and add the connection to DBML?
Note: When I used DataReader with the database name in a C# program, it worked well.
Query Used:
declare #sqlser varchar(20)
EXEC master..xp_regread #rootkey='HKEY_LOCAL_MACHINE',
#key='SYSTEM\CurrentControlSet\Services\MSSQLSERVER',
#value_name='objectname', #value=#sqlser OUTPUT
SELECT convert(varchar(30),#sqlser)
Working C# Program:
SqlDataReader rdr = null;
SqlConnection con = null;
SqlCommand cmd = null;
try
{
// Open connection to the database
string ConnectionString = "server=D088DTRV;integrated security=true; database=BankAccount";
con = new SqlConnection(ConnectionString);
con.Open();
string CommandText = "SELECT * FROM Account";
cmd = new SqlCommand(CommandText);
cmd.Connection = con;
rdr = cmd.ExecuteReader();
while (rdr.Read())
{
string test = rdr["AccountType"].ToString();
}
}
The problem was related to Data Connections.
In the advanced window, when I checked, it was trying for ./SQLExpress. I modified it with ".".
I restarted the machine. I also stopped the SQLExpress in the services.msc
Data Source=.;AttachDbFilename=C:\DevTEST\Databases\LibraryReservationSystem.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True