Hey Members i am new to C# Language and Visual Studio Platform recently i am learning how to connect access Database with visual Studio and first time with same code i have connected with database but after some time when i compiled again then there is error given in Title.
why this is happening ?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.OleDb;
namespace Clinic_Management_System
{
public partial class Login : Form
{
public Login()
{
InitializeComponent();
}
private void Login_Load(object sender, EventArgs e)
{
try
{
OleDbConnection connection = new OleDbConnection();
connection.ConnectionString = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users
\Hassan Gillani\Documents\Clinic Management System.accdb; Persist Security Info = False; ";
connection.Open();
label1.Text = "Connected to Clinic Management System Database";
connection.Close();
}
catch (Exception exp)
{
MessageBox.Show("Error " + exp);
}
}
}
}
please visit given like to view screen short
http://s33.postimg.org/5ltm4dtnj/Error.png
Using the verbatim character (#) and splitting your path in the middle in not a good idea.
Spaces counts in paths so the filename used for your connection is
C:\Users \Hassan Gillani\Documents\Clinic Management System.accdb;
If you try to use File.Exists on this string you get false as result.
Do not split your connection string in the middle of the path
connection.ConnectionString = #"Provider=Microsoft.ACE.OLEDB.12.0;
Data Source=C:\Users\Hassan Gillani\Documents\Clinic Management System.accdb;
Persist Security Info = False; ";
Related
I am creating a practice SQL Server database project, and I'm trying to enter text into a SQL Server database through a Windows Form. I'm not sure if my text data was really entered to my database. How do I view if it was entered? I'm a beginner so please try to use beginner SQL and VS vocabulary. I've tried going to show table data but that shows that no data was entered so I'm assuming its not working. Whenever I hit the button it just gives me no response so I'm not sure.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
namespace DBHotel
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
string connectionString = "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\Users\\Nicholas Hoffs\\source\\repos\\DBHotel\\DBHotel\\Hotel.mdf;Integrated Security=True";
private void instBttn_Click(object sender, EventArgs e)
{
string nameQuery = textInst.Text;
using(SqlConnection conn = new SqlConnection(connectionString))
{
using(SqlCommand cmd = new SqlCommand(nameQuery, conn))
{
conn.Open();
cmd.CommandText = "INSERT INTO Customers(name) VALUES(#nameQuery)";
cmd.Parameters.AddWithValue("nameQuery", nameQuery);
cmd.ExecuteNonQuery();
}
}
}
}
}
Help is very much appreciated, thanks!
I know this is nonintuitive but try using the # inside your AddWithValue:
cmd.Parameters.AddWithValue("#nameQuery", nameQuery);
EDIT: WARNING The below solution is at risk of sql injection, and is highly discouraged.
As you are using direct query in instead of using stored procedure, you can't pass parameter to SQL. Instead of passing parameter try using
cmd.CommandText = "INSERT INTO Customers(name) VALUES('" + nameQuery + "')";
this means we are just concatenating the value of variable "nameQuery" in the query itself. so no need of below statement
cmd.Parameters.AddWithValue("nameQuery", nameQuery);
Please help.
I have device MC3200 Zebra(motorola)(Windows Embedded version 7, build 2864). This device is connecting to network and see SQL server(ping is OK). I used it Visual Studio 2008, c#, SmartDevicePrj, .NET CF 3.5
But after start application on device will be displayed message:
Unknown connection option in connection string: initial catalog.
Some idea how to repair it?
Many thanks for your help.
using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;
namespace SmartDeviceProject1
{
public partial class Form1 : Form
{
public SqlCeConnection msConn;
public string strCon = "";
public SqlCeCommand command;
public Form1()
{
InitializeComponent();
strCon = "Data Source=server007; Initial Catalog=FMPredlis; User ID=mistr; Password=heslo;";
try
{
msConn = new SqlCeConnection(strCon);
msConn.Open();
MessageBox.Show("Připojeno");
}
catch (SqlCeException ex)
{
MessageBox.Show("Chyba" + ex.Message);
msConn.Close();
}
}
}
}
I think you are mixing 2 things.
Either use The SqlConnection object, then you can connect to a SQL Server using a connection string found on this page:
https://www.connectionstrings.com/sql-server/
Or use like in your code the SqlCEConnection, then you connect to a SQL Lite (local file), and your connection string should be like on this page:
https://www.connectionstrings.com/sqlite/
But in your sample you are using SqlCEConnection to connect to a sql server, that wont work.
Grtz
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Please advise me. I am trying to develop Windows Application in WPF with Mysql server database.
Which approach I have to use to create connection establish on the Mysql database?
1) Entity Framework
OR
2) ADO.NET
OR
3) Other one
The Admin computer need to install mysql database on his computer and then access the mysql database to another (10 or more) client systems which are under network connected.
Here, just one MySql database inside admin computer only. And all other client machines are accessing MySql database by admin's computer IP address. The IP connection string is like this:-
#"Data Source=10.0.0.101
One of other matter is, the customer demanding that, when installing .exe file on client machine, then should have to automatically install mysql server database (ie, xampp or other ect..) also.
How can I do this?
I have tried, ADO.NET C# instead EF to connect mysql for wpf windows application. like that :-
public void AddUserList( UserSetUp user)
{
dbConnection.Open();
string query = "INSERT INTO Tble_UserSetUp (FirstName, SurName, Email, PhoneNumber, UserName, Password,Computer_Name,IP_Address,CreatedBy, CreatedDate,IsActive,Function,Department) VALUES (#FirstName, #SurName, #Email, #PhoneNumber, #UserName, #Password,#Computer_Name,#IP_Address,#CreatedBy, #CreatedDate,#IsActive,#Function,#Department)";
MySqlCommand insertSQL = new MySqlCommand(query, (MySqlConnection)dbConnection);
insertSQL.Parameters.AddWithValue("#FirstName", user.FirstName);
insertSQL.Parameters.AddWithValue("#SurName", user.SurName);
insertSQL.Parameters.AddWithValue("#Email", user.Email);
insertSQL.Parameters.AddWithValue("#PhoneNumber", user.PhoneNumber);
insertSQL.Parameters.AddWithValue("#UserName", Encrypt(user.UserName));
insertSQL.Parameters.AddWithValue("#Password", Encrypt(user.Password));
insertSQL.Parameters.AddWithValue("#Computer_Name", user.Computer_Name);
insertSQL.Parameters.AddWithValue("#IP_Address", user.IP_Address);
insertSQL.Parameters.AddWithValue("#CreatedBy", user.CreatedBy);
insertSQL.Parameters.AddWithValue("#CreatedDate", user.CreatedDate);
insertSQL.Parameters.AddWithValue("#IsActive", user.IsActive);
insertSQL.Parameters.AddWithValue("#Function", user.Function);
insertSQL.Parameters.AddWithValue("#Department", user.Department);
try
{
insertSQL.ExecuteNonQuery();
dbConnection.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
Is it a bad idea instead of use Entity Framework or another one?
public partial class MainWindow : Window
{
/*mysql
*
* 1. add nuget mysql.data.dll（desktop application）
* 2. using MySql.Data.MySqlClient;
* 3. code like bellow , you can try
*/
private StringBuilder sb = new StringBuilder();
public MainWindow()
{
InitializeComponent();
mysql();
tbx.Text = sb.ToString();
}
private void mysql()
{
try
{
var connstr = "Server=localhost;Uid=root;Pwd=123456;database=world";
using (var conn = new MySqlConnection(connstr))
{
conn.Open();
using (var cmd = conn.CreateCommand())
{
cmd.CommandText = "select * from city where countryCode= #ID";
cmd.Parameters.AddWithValue("#ID", "100");
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
var ii = reader.FieldCount;
for (int i = 0; i < ii; i++)
{
if (reader[i] is DBNull)
sb.AppendLine("null");
else
sb.AppendLine(reader[i].ToString());
}
}
}
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
}
Reference: Official MySQL documentation - Introduction to Connector/NET Programming
Step 0: Setup MySql and Create a database
Step 1: Create WPF Project
Step 2: Install MySql.Data package using Nuget package manager
(Visual Studio) Project> (click) Manage NuGet packages
Select Browse tab> search Mysql.data > Select Mysql.data package> Install
Step 3: In my case I created the connection within MainWindow.xaml.cs file.
To consume MySql.Data and MySql.Data.MySqlClient
using MySql.Data;
using MySql.Data.MySqlClient;
Full Code (relevent to the question): MainWindow.xaml.cs file
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using MySql.Data;
using MySql.Data.MySqlClient;
namespace EAppartments
{
public partial class MainWindow : Window
{
string connStr = "server=localhost;user=root;database=YourDBName;password=yourpassword";
//Connect to MySql when app starts
//you can use OnStartUp event as well
public MainWindow()
{
InitializeComponent();
connectToMySql();
}
private void connectToMySql()
{
MySqlConnection conn = new MySqlConnection(connStr);
try
{
Console.WriteLine("Connecting to MySQL...");
conn.Open();
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
//close connection if you want
conn.Close();
Console.WriteLine("Done.");
}
}
}
Useful resources:
Execute MySql commands using WPF app
Lifecycle of WPF application
i have a web server on internet i am using php/mysql. for my website, now i want to connect to my mysql database on my webserver using my c# windows form application so that i will be able to view,create, update, delete the data on mysql database on webserver, i want to user same database for website and my desktop application. i want any one having my desktop application would be able to update my database on my webserver(i mean not only form some specific ip).
Here is my code when i try to run it shows error "Unable to connect to any of specified MySQL hosts."
can any one Guide me how to do it. Thanks.
The following code is working fine for localhost but not working for web-server which is on internet.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MySql.Data.MySqlClient; // for mysql
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
string con_str = "SERVER=fdb4.biz.nf;Port=3306;DATABASE=1558711_zee;UID=1558711_zee;PASSWORD=multan321;compress=true;";
MySqlConnection connection = new MySqlConnection(con_str);
try {
connection.Open();
MySqlCommand cmd = connection.CreateCommand();
cmd.CommandText = "SELECT * FROM zeetable";
MySqlDataAdapter mda = new MySqlDataAdapter(cmd);
DataSet mds = new DataSet();
mda.Fill(mds);
dataGridView1.DataSource = mds.Tables[0].DefaultView;
}
catch(MySqlException ex){
MessageBox.Show(ex.Message);
}
}
}
}
for this i am not getting any output thought there is not any error or warning... i guess the problem is with connection string but not sure, is it?? i have created a database name RV(.mdf file) in SQL server data tool and connected it to this project in visual studio.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using System.Configuration;
namespace student_TableConnectTry1
{
class Program
{
static void Main(string[] args)
{
using (SqlConnection cn = new SqlConnection())
{
cn.ConnectionString =#"Data Source=(local);Integrated Security=SSPI;" +"Initial Catalog=RV";
cn.Open();
string strSQL = "Select * From student";
SqlCommand myCommand = new SqlCommand(strSQL, cn);
using (SqlDataReader myDataReader = myCommand.ExecuteReader())
{
// Loop over the results.
while (myDataReader.Read())
{
Console.WriteLine("-> usn: {0}, name: {1}.",
myDataReader["usn"].ToString(),
myDataReader["name"].ToString()
);
}
}
Console.ReadLine();
}
}
}
}
You can use following connection string and try:
Integrated Security=SSPI;Persist Security Info=False;User ID=youruserid;Initial Catalog=databasename;Data Source=.\SQLEXPRESS
Also see the following link for connectionstring:
http://www.connectionstrings.com/sql-server/
I hope it will help you. :)
Let me know if it does not help you.