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2010-05-26T15:31:19Z

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==Creating Data Tables and Populating Them==

<source lang="csharp">
/*
* 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");
}
}
}

</source>

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

<source lang="csharp">
/*
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("\nAdding a new row with CustomerID of "T1COM"");
// 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.rumandText = 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("\nModifying 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.rumandText = 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("\nRemoving 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.rumandText = 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 ("ALFKI", "T1COM")";
// 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.rumandText = 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();
}
}

</source>

==Update A DataSource==

<source lang="csharp">
/*
* 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.OleDb;
namespace Client.Chapter_13___ADO.NET
{
public class UpdatingADataSource
{
static void Main(string[] args)
{
OleDbConnection MyConnection = new OleDbConnection(@"Provider=Microsft.Jet.OLEDB.4.0; Data Source = c:\MyAccessDB.mdb");
OleDbDataAdapter MyAdapter = new OleDbDataAdapter("SELECT Column1, Column2, Column3 FROM MyTable", MyConnection);
DataSet MyDataSet = new DataSet();
MyAdapter.Fill(MyDataSet, "MyTable");
MyDataSet.Tables[0].Rows[3]["Column3"] = "Test";
OleDbCommandBuilder MyBuilder = new OleDbCommandBuilder(MyAdapter);
MyAdapter.Update(MyDataSet.Tables[0]);
}
}
}

</source>

==Update Data Using Commond Builder==

<source lang="csharp">
/*
* 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 UpdatingDataUsingCommondBuilder
{
static void Main(string[] args)
{
SqlConnection MyConnection = new SqlConnection(@"Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");
SqlDataAdapter MyDataAdapter = new SqlDataAdapter("SELECT ID, Contact, Email FROM Test", MyConnection);
DataSet MyDataSet = new DataSet();
MyDataAdapter.Fill(MyDataSet);
MyDataSet.Tables[0].Rows[0][0] = 55;
SqlCommandBuilder MyCmd = new SqlCommandBuilder(MyDataAdapter);
MyDataAdapter.Update(MyDataSet);
}
}
}

</source>

==Update Data Using Sql Statements 2==

<source lang="csharp">
/*
* 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 UpdatingDataUsingSqlStatements
{
static void Main(string[] args)
{
SqlConnection MyConnection = new SqlConnection(@"Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");
MyConnection.Open();
String MyString = "UPDATE Test SET Contact = "Lee"";
SqlCommand MyCmd = new SqlCommand(MyString, MyConnection);
MyCmd.ExecuteScalar();
MyConnection.Close();
}
}
}

</source>

==Update table using SqlDataAdapter==

<source lang="csharp">
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();
}
}
}

</source>

==Use DataTable to update table in Database==

<source lang="csharp">
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();
}
}
}

</source>

==Using Data Table Mappings==

<source lang="csharp">
/*
* 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.rumon;
using System.Data.SqlClient;
namespace Client.Chapter_13___ADO.NET
{
public class UsingDataTableMappings
{
static void Main(string[] args)
{
SqlConnection SConn = new SqlConnection("Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");
SqlDataAdapter da = new SqlDataAdapter("SELECT ID, Contact, Email FROM CaseInfo", SConn);
DataSet ds = new DataSet();
DataTableMapping custMap = da.TableMappings.Add("CaseInfo", "MyDatabase");
custMap.ColumnMappings.Add("ID", "CaseNumber");
custMap.ColumnMappings.Add("Contact", "MyContact");
custMap.ColumnMappings.Add("Email", "Email Address");
da.Fill(ds);
}
}
}

</source>

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в 15:31, 26 мая 2010

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