Creating Data Tables and Populating Them

/*
* C# Programmers Pocket Consultant
* Author: Gregory S. MacBeth
* Email: gmacbeth@comporium.net
* Create Date: June 27, 2003
* Last Modified Date:
* Version: 1
*/
using System;
using System.Data;
using System.Data.SqlClient;

namespace Client.Chapter_13___ADO.NET
{
public class CreatingDataTablesandPopulatingThem
{
static void Main(string[] args)
{
SqlConnection MyConnection = new SqlConnection(@”Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true”);
SqlDataAdapter MyAdapter = new SqlDataAdapter(“SELECT * FROM CaseInfo”, MyConnection);
DataSet MyDataSet = new DataSet();

//Create a new DataTable
DataTable MyTable2 = MyDataSet.Tables.Add(“My2ndTable”);

//Adding Columns and Rows
DataColumn myColumn = new DataColumn();

myColumn.DataType = System.Type.GetType(“System.Decimal”);
myColumn.AllowDBNull = false;
myColumn.Caption = “Price”;
myColumn.ColumnName = “Price”;
myColumn.DefaultValue = 25;

// Add the column to the table.
MyTable2.Columns.Add(myColumn);

// Add 10 rows and set values.
DataRow myRow;

for (int i = 0; i < 10; i++) { myRow = MyTable2.NewRow(); myRow[0] = i + 1; // Be sure to add the new row to the DataRowCollection. MyTable2.Rows.Add(myRow); } SqlCommandBuilder Builder = new SqlCommandBuilder(MyAdapter); MyAdapter.Update(MyDataSet, "My2ndTable"); } } } [/csharp]

Illustrates how to perform INSERT, UPDATE, and DELETE statements using ADO.NET

   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example23_2.cs illustrates how to perform INSERT, UPDATE,
  and DELETE statements using ADO.NET
*/

using System;
using System.Data;
using System.Data.SqlClient;

public class Example23_2
{

  public static void DisplayDataTable(
    SqlDataAdapter mySqlDataAdapter,
    DataSet myDataSet,
    DataTable myDataTable
  )
  {

    // use the Clear() method of the DataSet object
    // to remove all the rows in the DataSet
    myDataSet.Clear();

    // use the Fill() method of the SqlDataAdapter object
    // to synchronize any changes made to the database
    // with the DataSet object
    mySqlDataAdapter.Fill(myDataSet, "Customers");

    // display the columns for each row in the DataTable,
    // using a DataRow object to access each row in the DataTable
    foreach (DataRow myDataRow in myDataTable.Rows)
    {
      Console.WriteLine("CustomerID = " + myDataRow["CustomerID"]);
      Console.WriteLine("CompanyName = " + myDataRow["CompanyName"]);
      Console.WriteLine("ContactName = " + myDataRow["ContactName"]);
      Console.WriteLine("Address = " + myDataRow["Address"]);
    }

  }

  public static void AddRow(
    SqlConnection mySqlConnection,
    SqlDataAdapter mySqlDataAdapter,
    DataSet myDataSet
  )
  {

    Console.WriteLine("
Adding a new row with CustomerID of &#039;T1COM&#039;");

    // step 1: formulate a string containing the SQL statement
    string insertString =
      "INSERT INTO Customers (" +
      "  CustomerID, CompanyName, ContactName, Address" +
      ") VALUES (" +
      "  @CustomerID, @CompanyName, @ContactName, @Address" +
      ")";

    // step 2: create a SqlCommand object to hold the SQL statement
    SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

    // step 3: set the CommandText property of the SqlCommand object to
    // the SQL string
    mySqlCommand.CommandText = insertString;

    // step 4: use the Add() method through the Parameters property
    // of the SqlCommand object to add the parameters to the SqlCommand
    // object
    mySqlCommand.Parameters.Add("@CustomerID", SqlDbType.NChar, 5);
    mySqlCommand.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40);
    mySqlCommand.Parameters.Add("@ContactName", SqlDbType.NVarChar, 30);
    mySqlCommand.Parameters.Add("@Address", SqlDbType.NVarChar, 60);

    // step 5: set the parameters to specified values using the
    // Value property
    mySqlCommand.Parameters["@CustomerID"].Value = "T1COM";
    mySqlCommand.Parameters["@CompanyName"].Value = "T1 Company";
    mySqlCommand.Parameters["@ContactName"].Value = "Jason Price";
    mySqlCommand.Parameters["@Address"].Value = "1 Main Street";

    // step 6: use the ExecuteNonQuery() method to run the
    // SQL statement
    mySqlCommand.ExecuteNonQuery();

  }

  public static void ModifyRow(
    SqlConnection mySqlConnection,
    SqlDataAdapter mySqlDataAdapter,
    DataSet myDataSet
  )
  {

    Console.WriteLine("
Modifying the new row");

    // step 1: formulate the SQL statement
    string updateString =
      "UPDATE Customers " +
      "SET " +
      "  CompanyName = @CompanyName, " +
      "  ContactName = @ContactName, " +
      "  Address = @Address " +
      "WHERE CustomerID = @CustomerID";

    // step 2: create a SqlCommand object to hold the SQL statement
    SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

    // step 3: set the CommandText property of the SqlCommand object to
    // the SQL string
    mySqlCommand.CommandText = updateString;

    // step 4: use the Add() method through the Parameters property
    // to add the parameters
    mySqlCommand.Parameters.Add("@CustomerID", SqlDbType.NChar, 5);
    mySqlCommand.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40);
    mySqlCommand.Parameters.Add("@ContactName", SqlDbType.NVarChar, 30);
    mySqlCommand.Parameters.Add("@Address", SqlDbType.NVarChar, 60);

    // step 5: set the parameters to values using the Value property
    mySqlCommand.Parameters["@CustomerID"].Value = "T1COM";
    mySqlCommand.Parameters["@CompanyName"].Value = "Widgets Inc.";
    mySqlCommand.Parameters["@ContactName"].Value = "John Smith";
    mySqlCommand.Parameters["@Address"].Value = "1 Any Street";

    // step 6: use the ExecuteNonQuery() method to run the
    // SQL statement
    mySqlCommand.ExecuteNonQuery();

  }

  public static void RemoveRow(
    SqlConnection mySqlConnection,
    SqlDataAdapter mySqlDataAdapter,
    DataSet myDataSet
  )
  {

    Console.WriteLine("
Removing the new row");

    // step 1: formulate the SQL statement
    string deleteString =
      "DELETE FROM Customers " +
      "WHERE CustomerID = @CustomerID";

    // step 2: create a SqlCommand object to hold the SQL statement
    SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

    // step 3: set the CommandText property of the SqlCommand object to
    // the SQL string
    mySqlCommand.CommandText = deleteString;

    // step 4: use the Add() method through the Parameters property
    // to add the parameter
    mySqlCommand.Parameters.Add("@CustomerID", SqlDbType.NChar, 5);

    // step 5: set the parameters to values using the Value property
    mySqlCommand.Parameters["@CustomerID"].Value = "T1COM";

    // step 6: use the ExecuteNonQuery() method to run the
    // SQL statement
    mySqlCommand.ExecuteNonQuery();

  }

  public static void Main()
  {

    // formulate a string containing the details of the
    // database connection
    string connectionString =
      "server=localhost;database=Northwind;uid=sa;pwd=sa";

    // create a SqlConnection object to connect to the
    // database, passing the connection string to the constructor
    SqlConnection mySqlConnection =
      new SqlConnection(connectionString);

    // formulate a SELECT statement to retrieve the
    // CustomerID, CompanyName, ContactName, and Address
    // columns for rows from the Customers table
    string selectString =
      "SELECT CustomerID, CompanyName, ContactName, Address " +
      "FROM Customers " +
      "WHERE CustomerID IN (&#039;ALFKI&#039;, &#039;T1COM&#039;)";

    // create a SqlCommand object to hold the SELECT statement
    SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

    // set the CommandText property of the SqlCommand object to
    // the SELECT string
    mySqlCommand.CommandText = selectString;

    // create a SqlDataAdapter object
    SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter();

    // set the SelectCommand property of the SqlAdapter object
    // to the SqlCommand object
    mySqlDataAdapter.SelectCommand = mySqlCommand;

    // create a DataSet object to store the results of
    // the SELECT statement
    DataSet myDataSet = new DataSet();

    // open the database connection using the
    // Open() method of the SqlConnection object
    mySqlConnection.Open();

    // use the Fill() method of the SqlDataAdapter object to
    // retrieve the rows from the table, storing the rows locally
    // in a DataTable of the DataSet object
    string dataTableName = "Customers";
    Console.WriteLine("Retrieving a row from the Customers table");
    mySqlDataAdapter.Fill(myDataSet, dataTableName);

    // get the DataTable object from the DataSet object
    DataTable myDataTable = myDataSet.Tables[dataTableName];

    // display the rows in the DataTable object
    DisplayDataTable(mySqlDataAdapter, myDataSet, myDataTable);

    // add a new row
    AddRow(mySqlConnection, mySqlDataAdapter, myDataSet);
    DisplayDataTable(mySqlDataAdapter, myDataSet, myDataTable);

    // modify the new row
    ModifyRow(mySqlConnection, mySqlDataAdapter, myDataSet);
    DisplayDataTable(mySqlDataAdapter, myDataSet, myDataTable);

    // remove the new row
    RemoveRow(mySqlConnection, mySqlDataAdapter, myDataSet);
    DisplayDataTable(mySqlDataAdapter, myDataSet, myDataTable);

    // close the database connection using the Close() method
    // of the SqlConnection object
    mySqlConnection.Close();

  }

}


           
          


Update table using SqlDataAdapter

   


using System;
using System.Data;
using System.Data.SqlClient;

   class PropagateChanges {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
         string qry = @"select * from employee ";
         string upd = @"update employee set firstname = @firstname where id = @id";

         SqlConnection conn = new SqlConnection(connString);

         try {
            SqlDataAdapter da = new SqlDataAdapter();
            da.SelectCommand = new SqlCommand(qry, conn);

            DataSet ds = new DataSet();   
            da.Fill(ds, "employee");

            DataTable dt = ds.Tables["employee"];

            dt.Rows[0]["firstname"] = "W";

            foreach (DataRow row in dt.Rows){
               Console.WriteLine(
                  "{0} {1}",
                  row["firstname"].ToString().PadRight(15),
                  row["lastname"].ToString().PadLeft(25));
            }

            // Update employees
            SqlCommand cmd = new SqlCommand(upd, conn);
            cmd.Parameters.Add("@firstname",SqlDbType.NVarChar,15, "firstname");
            SqlParameter parm = cmd.Parameters.Add("@id",SqlDbType.Int,4,"id");
            parm.SourceVersion = DataRowVersion.Original;
            da.UpdateCommand = cmd;
            da.Update(ds, "employee");
         } catch(Exception e) {
            Console.WriteLine("Error: " + e);
         } finally {
            conn.Close();
         }
      }  
   }


           
          


Use DataTable to update table in Database

   

using System;
using System.Data;
using System.Data.SqlClient;

   class PropagateAddsBuilder {
      static void Main() {
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
         string qry = @"select * from employee";
 
         SqlConnection conn = new SqlConnection(connString);

         try {
            SqlDataAdapter da = new SqlDataAdapter();
            da.SelectCommand = new SqlCommand(qry, conn);

            SqlCommandBuilder cb = new SqlCommandBuilder(da);

            DataSet ds = new DataSet();   
            da.Fill(ds, "employee");

            DataTable dt = ds.Tables["employee"];

            // Add a row
            DataRow newRow = dt.NewRow();
            newRow["firstname"] = "y";
            newRow["lastname"] = "y";
            dt.Rows.Add(newRow);

            foreach (DataRow row in dt.Rows){
               Console.WriteLine(
                  "{0} {1}",
                  row["firstname"].ToString().PadRight(15),
                  row["lastname"].ToString().PadLeft(25));
            }

            da.Update(ds, "employee");
         } catch(Exception e)  {
            Console.WriteLine("Error: " + e);
         } finally {
            conn.Close();
         }
      }  
   }



           
          


Update Data Using Transactions

   


/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 * Version: 1
 */
using System;
using System.Data;
using System.Data.SqlClient;

namespace Client.Chapter_13___ADO.NET
{
    public class UpdatingDataUsingTransactions
    {
        static void Main(string[] args)
        {
            SqlConnection MyConnection = new SqlConnection(@"Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");

            MyConnection.Open();

            String MyString = "INSERT INTO Test(ID, Contact, Email)VALUES(1, &#039;Greg&#039;, &#039;Mac&#039;)";
            SqlTransaction MyTransaction = MyConnection.BeginTransaction();
            SqlCommand MyCmd = new SqlCommand(MyString, MyConnection, MyTransaction);

            MyCmd.ExecuteScalar();
            MyTransaction.Commit();
            MyConnection.Close();
        }
    }
}
           
          


Commit two delete sql command

   


using System;
using System.Data;
using System.Data.SqlClient;

   class SqlDemo {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";

         SqlConnection cn = new SqlConnection(connString);
         cn.Open();

         SqlTransaction objTrans = cn.BeginTransaction();

         try{
            SqlCommand cmd = cn.CreateCommand();
            cmd.CommandType = CommandType.Text;
            cmd.Transaction = objTrans;

            cmd.CommandText = "DELETE Employee WHERE Id = 222";
            cmd.ExecuteNonQuery();

            cmd.CommandText="DELETE Employee WHERE Id = 333";
            cmd.ExecuteNonQuery();

            objTrans.Commit();

            Console.WriteLine("Transaction Committed
");
         }
         catch (System.Data.SqlClient.SqlException  ex)
         {
            objTrans.Rollback();  

            Console.WriteLine("Error - TRANSACTION ROLLED BACK
" + ex.Message);
         }
         catch (System.Exception ex)
         {
            Console.WriteLine("System Error
" + ex.Message);
         }
         finally
         {
            cn.Close();  
         }
      }
   }

           
          


Transaction roll back and commit

   


using System;
using System.Data;
using System.Data.SqlClient;

   class SqlDemo {
      static void Main(){
         string connString = "server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";

         SqlConnection cn = new SqlConnection(connString);
         cn.Open();

         SqlTransaction objTrans = cn.BeginTransaction();

         try 
         {      
            SqlCommand cmd = cn.CreateCommand();
            cmd.CommandType = CommandType.Text;
            cmd.Transaction = objTrans;

            cmd.CommandText = "DELETE Employee WHERE Id = 222";
            cmd.ExecuteNonQuery();

            objTrans.Commit();
        
            Console.WriteLine("Transaction Committed
" );
         }
         catch (System.Data.SqlClient.SqlException ex)
         {
            objTrans.Rollback();
            Console.WriteLine("Error - TRANSACTION ROLLED BACK
" + ex.Message);
         }
         catch (System.Exception ex)
         {
            Console.WriteLine("System Error
" + ex.Message);
         }
         finally
         {
            cn.Close();
         }
      }
   }