в 15:31, 26 мая 2010

2010-05-26T15:31:53Z

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2010-05-26T12:19:04Z

1 версия

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==Accessing Data Values in a DataRow Array by column name==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect ="SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable();
da.Fill(dt);
DataRow[] dra = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(dra, 0);
Console.WriteLine("FirstName = {0}", dra[2]["FirstName"]);
}
}</source>

==Accessing Data Values in a DataRow Array by column name and return default value==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect ="SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable();
da.Fill(dt);
DataRow[] dra = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(dra, 0);
Console.WriteLine("FirstName = {0}",dra[2]["FirstName", DataRowVersion.Default]);
}
}</source>

==Accessing Data Values in a DataRow Array by index==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect ="SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable();
da.Fill(dt);
DataRow[] dra = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(dra, 0);
Console.WriteLine("FirstName = {0}", dra[2][1]);
}
}</source>

==Accessing Data Values in a DataRow Array in a generic way by index==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect ="SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable();
da.Fill(dt);
DataRow[] dra = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(dra, 0);
Console.WriteLine("FirstName = {0}", dra[2].Field<string>(1));
}
}</source>

==Accessing Data Values in a DataRow Array in a generic way by name==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect ="SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable();
da.Fill(dt);
DataRow[] dra = new DataRow[dt.Rows.Count];
dt.Rows.CopyTo(dra, 0);
Console.WriteLine("FirstName = {0}",dra[2].Field<string>("FirstName"));
Console.WriteLine("FirstName = {0}",dra[2].Field<string>("FirstName", DataRowVersion.Default));
}
}</source>

==Create and fill the DataRow array==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);

DataTable dt1 = new DataTable();
da.Fill(dt1);
DataRow[] dra = new DataRow[dt1.Rows.Count];
dt1.Rows.CopyTo(dra, 0);
for (int i = 0; i < dra.Length; i++){
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
dra[i].Field<int>("ContactID"), dra[i].Field<string>("FirstName"),
dra[i].Field<string>("LastName"));
}
}
}</source>

==DataRowState manipulation==

<source lang="csharp">using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
class Program
{
static void Main(string[] args)
{
DataTable temp = new DataTable("Temp");
temp.Columns.Add(new DataColumn("TempColumn", typeof(int)));
DataRow row = temp.NewRow();
Console.WriteLine("After calling NewRow(): {0}", row.RowState);
temp.Rows.Add(row);
Console.WriteLine("After calling Rows.Add(): {0}", row.RowState);
row["TempColumn"] = 10;
Console.WriteLine("After first assignment: {0}", row.RowState);
temp.AcceptChanges();
Console.WriteLine("After calling AcceptChanges: {0}", row.RowState);
row["TempColumn"] = 11;
Console.WriteLine("After first assignment: {0}", row.RowState);
temp.Rows[0].Delete();
Console.WriteLine("After calling Delete: {0}", row.RowState);
}
}</source>

==DataRow Update==

<source lang="csharp">using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.rumon;
public class DataRowUpdateState : System.Windows.Forms.Form
{
private System.Windows.Forms.DataGrid dataGrid1;
private System.ruponentModel.Container components = null;
public DataRowUpdateState()
{
InitializeComponent();
CreateCustomersTable();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
private void InitializeComponent()
{
this.dataGrid1 = new System.Windows.Forms.DataGrid();
((System.ruponentModel.ISupportInitialize)(this.dataGrid1)).BeginInit();
this.SuspendLayout();
//
// dataGrid1
//
this.dataGrid1.DataMember = "";
this.dataGrid1.Location = new System.Drawing.Point(8, 8);
this.dataGrid1.Name = "dataGrid1";
this.dataGrid1.Size = new System.Drawing.Size(416, 296);
this.dataGrid1.TabIndex = 0;
//
// DataRowUpdateState
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(432, 309);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.dataGrid1});
this.Name = "DataRowUpdateState";
this.Text = "DataRowUpdateState";
((System.ruponentModel.ISupportInitialize)(this.dataGrid1)).EndInit();
this.ResumeLayout(false);
}
[STAThread]
static void Main()
{
Application.Run(new DataRowUpdateState());
}
private void CreateCustomersTable()
{
System.Data.DataTable custTable = new DataTable("Customers");
DataColumn dtColumn;

dtColumn = new DataColumn();
dtColumn.DataType = System.Type.GetType("System.Int32");
dtColumn.ColumnName = "id";
dtColumn.Caption = "Cust ID";
dtColumn.ReadOnly = true;
dtColumn.Unique = true;
custTable.Columns.Add(dtColumn);
dtColumn = new DataColumn();
dtColumn.DataType = System.Type.GetType("System.String");
dtColumn.ColumnName = "Name";
dtColumn.Caption = "Cust Name";
dtColumn.AutoIncrement = false;
dtColumn.ReadOnly = false;
dtColumn.Unique = false;
custTable.Columns.Add(dtColumn);
dtColumn = new DataColumn();
dtColumn.DataType = System.Type.GetType("System.String");
dtColumn.ColumnName = "Address";
dtColumn.Caption = "Address";
dtColumn.ReadOnly = false;
dtColumn.Unique = false;
// Add Address column to the table.
custTable.Columns.Add(dtColumn);
DataColumn[] PrimaryKeyColumns = new DataColumn[1];
PrimaryKeyColumns[0] = custTable.Columns["id"];
custTable.PrimaryKey = PrimaryKeyColumns;
DataSet ds = new DataSet("Customers");
ds.Tables.Add(custTable);
DataRow row1 = custTable.NewRow();
row1["id"] = 1;
row1["Address"] = "USA";
row1["Name"] = "George";
custTable.Rows.Add(row1);
MessageBox.Show(row1.RowState.ToString());
row1.RejectChanges();
MessageBox.Show(row1.RowState.ToString());
row1.Delete();
MessageBox.Show(row1.RowState.ToString());

dataGrid1.DataSource = ds.DefaultViewManager;
}
}</source>

==DataView and DataRowView==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class DataViews
{
static void Main(string[] args)
{
string connString = @"server = .\sqlexpress;integrated security = true;database = northwind";
string sql = @"select contactname,country from customers";
SqlConnection conn = new SqlConnection(connString);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = new SqlCommand(sql, conn);
DataSet ds = new DataSet();
da.Fill(ds, "customers");
DataTable dt = ds.Tables["customers"];
DataView dv = new DataView(dt,"country = "Germany"","country",DataViewRowState.CurrentRows);
foreach (DataRowView drv in dv)
{
for (int i = 0; i < dv.Table.Columns.Count; i++)
Console.Write(drv[i] + "\t");
}
}
catch (Exception e)
{
Console.WriteLine("Error: " + e);
}
finally
{
conn.Close();
} Console.ReadLine();
}
}</source>

==Filling a DataTable from the DataRow array using CopyToDataTable()==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);

DataTable dt1 = new DataTable();
da.Fill(dt1);
DataRow[] dra = new DataRow[dt1.Rows.Count];
dt1.Rows.CopyTo(dra, 0);
for (int i = 0; i < dra.Length; i++){
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
dra[i].Field<int>("ContactID"), dra[i].Field<string>("FirstName"),
dra[i].Field<string>("LastName"));
}
DataTable dt2 = dra.CopyToDataTable();
foreach (DataRow row in dt2.Rows)
{
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
row["ContactID"], row["FirstName"], row["LastName"]);
}
}
}</source>

==Filling a DataTable from the DataRow array using CopyToDataTable(DataTable, LoadOption)==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);

DataTable dt1 = new DataTable();
da.Fill(dt1);
DataRow[] dra = new DataRow[dt1.Rows.Count];
dt1.Rows.CopyTo(dra, 0);
for (int i = 0; i < dra.Length; i++){
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
dra[i].Field<int>("ContactID"), dra[i].Field<string>("FirstName"),
dra[i].Field<string>("LastName"));
}
DataTable dt2 = dra.CopyToDataTable();
foreach (DataRow row in dt2.Rows)
{
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
row["ContactID"], row["FirstName"], row["LastName"]);
}
DataTable dt3 = dt1.Clone();
dra.CopyToDataTable(dt3, LoadOption.Upsert);
foreach (DataRow row in dt3.Rows)
{
Console.WriteLine("ContactID = {0}\tFirstName = {1}\tLastName = {2}",row["ContactID"], row["FirstName"], row["LastName"]);
}
}
}</source>

==For loop over DataRow array==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);

DataTable dt1 = new DataTable();
da.Fill(dt1);
DataRow[] dra = new DataRow[dt1.Rows.Count];
dt1.Rows.CopyTo(dra, 0);
for (int i = 0; i < dra.Length; i++){
Console.WriteLine(
"ContactID = {0}\tFirstName = {1}\tLastName = {2}",
dra[i].Field<int>("ContactID"), dra[i].Field<string>("FirstName"),
dra[i].Field<string>("LastName"));
}
}
}</source>

==Get column value in a row==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable( );
da.Fill(dt);
for (int i = 0; i < 5; i++)
{
DataRow row = dt.Rows[i];
Console.WriteLine(i);
Console.WriteLine(row[0]);
Console.WriteLine(row["FirstName"]);
Console.WriteLine(row[2, DataRowVersion.Default]);
}

}
}</source>

==Get first index in a row==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable( );
da.Fill(dt);
for (int i = 0; i < 5; i++)
{
DataRow row = dt.Rows[i];
Console.WriteLine(i);
Console.WriteLine(row[0]);
Console.WriteLine(row["FirstName"]);
Console.WriteLine(row[2, DataRowVersion.Default]);
}

}
}</source>

==Get value from a row with default value==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable( );
da.Fill(dt);
for (int i = 0; i < 5; i++)
{
DataRow row = dt.Rows[i];
Console.WriteLine(i);
Console.WriteLine(row[0]);
Console.WriteLine(row["FirstName"]);
Console.WriteLine(row[2, DataRowVersion.Default]);
}

}
}</source>

==Using foreach statement with DataRow in DataTable==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class Program
{
static void Main(string[] args)
{
string sqlConnectString = "Data Source=(local);Integrated security=SSPI;Initial Catalog=AdventureWorks;";
string sqlSelect = "SELECT ContactID, FirstName, LastName FROM Person.Contact";
SqlDataAdapter da = new SqlDataAdapter(sqlSelect, sqlConnectString);
DataTable dt = new DataTable( );
da.Fill(dt);
int j = 0;
foreach (DataRow row in dt.Rows)
{
j++;
Console.WriteLine("Row = {0}\tContactID = {1}\tFirstName = {2}\tLastName = {3}", j, row[0], row["FirstName"],row["LastName", DataRowVersion.Default]);
}
}
}</source>

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Csharp/CSharp Tutorial/ADO.Net/DataRow - История изменений

в 15:31, 26 мая 2010

Admin: 1 версия