Thursday, November 11, 2010

c# connecting mysql and select ,insert ,delete

The MySQL Connector/Net allows you to create a graphical Windows application that is data-based. When your application runs, it must connect to a MySQL database. To support this connection, you can use the MySqlConnection class that is defined in the MySql.Data.MySqlClient namespace. Before using this class, you can first include that namespace in your file.

How to include :
1. Add Reference
2. Browse
3. Select File 'MySql.Data.dll'
at
C:\Program Files\MySQL\MySQL Connector Net
1.0.3\bin.\NET 1.1
4. You put code
using MySql.Data.MySqlClient;

Create a connection with mysql database :

MySqlConnection conn = new MySqlConnection("Network Address=localhost;" + "Initial Catalog='test';"   +"Persist Security Info=no;" + "User Name='root';" + "Password=''");

After creating a connection string, to apply it and actually establish the connection, you must call the MySqlConnection.Open(). Its syntax is:
public void Open();
 
As you can see, this method doesn't take any argument. 
The MySqlConnection object that calls it is responsible 
to get the connection string ready. If the connection 
fails, the compiler would throw a MySqlException exception. 
If the connection string doesn't contain a data source or 
server, the compiler would throw an  
InvalidOperationException
exception. 
After using a connection and getting the necessary information from it, you should terminate it. To close a connection, you can call the MySqlConnection.Close() method. Its syntax is:

public void Close();


This method is simply called to close the current connection. While you should avoid 
calling the Open() method more than once if a connection is already opened, you can 
call the Close() method more than once.


 Select Data : 

 To read data from a mysql table add following code under a button . 


MySqlConnection conn = new MySqlConnection("Network Address=localhost;" + "Initial Catalog='test';" +"Persist Security Info=no;" +
                                                                "User Name='root';" +
                                                                "Password=''");

            MySqlCommand command = conn.CreateCommand();
            MySqlDataReader Reader;
            command.CommandText = "select name from student where id='1'";
            conn.Open();
            Reader = command.ExecuteReader();
            while (Reader.Read())
            {
                string thisrow = "";
                for (int i = 0; i < Reader.FieldCount;i++)
                    thisrow += Reader.GetValue(i).ToString() + ",";
                MessageBox.Show(thisrow);
            }
            conn.Close();







 Insert Data: 



 MySqlConnection conn = new MySqlConnection("Network Address=localhost;" + "Initial Catalog='test';" + "Persist Security Info=no;" +  "User Name='root';" +"Password=''");

            conn.Open();

            MySqlCommand command = conn.CreateCommand();

            command.CommandText = "insert into student(name,address)values('sanjoy','kaunia')";

            MySqlDataReader result = command.ExecuteReader();

            MessageBox.Show("successfully inserted");

            result.Close();

            conn.Close();






Delete Data:



MySqlConnection conn = new MySqlConnection("Network Address=localhost;" + "Initial Catalog='test';" + "Persist Security Info=no;" +
                                                                "User Name='root';" +
                                                                "Password=''");

            conn.Open();

            MySqlCommand command = conn.CreateCommand();

            command.CommandText = "delete from student where id='1'";

            MySqlDataReader result = command.ExecuteReader();

            MessageBox.Show("successfully deleted");

            result.Close();

            conn.Close();
       

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