в 15:31, 26 мая 2010

2010-05-26T15:31:02Z

Admin: 1 версия

2010-05-26T12:06:22Z

1 версия

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==Add columns to DataTable==

<source lang="csharp">
#include "stdafx.h"
using namespace System;
using namespace System::Data;
void main()
{
DataSet^ myDataSet = gcnew DataSet("Game Data");
myDataSet->Tables->Add("Player");
myDataSet->Tables->Add("Score");
DataTable^ playerTable = myDataSet->Tables["Player"];
DataColumn^ firstNameColumn1 = playerTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn1 = playerTable->Columns->Add("Last Name",String::typeid);
playerTable->Columns->Add("Email", String::typeid);
}

</source>

==Add foreign key to the DataTable==

<source lang="csharp">
#include "stdafx.h"
using namespace System;
using namespace System::Data;
void main()
{
DataSet^ myDataSet = gcnew DataSet("Game Data");
myDataSet->Tables->Add("Player");
myDataSet->Tables->Add("Score");
DataTable^ playerTable = myDataSet->Tables["Player"];
DataColumn^ firstNameColumn1 = playerTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn1 = playerTable->Columns->Add("Last Name",String::typeid);
playerTable->Columns->Add("Email", String::typeid);
array<DataColumn^>^ primaryKey = {firstNameColumn1, lastNameColumn1};
playerTable->Constraints->Add("PlayerPK", primaryKey, true);
// Add columns to 2nd table
DataTable^ ScoreTable = myDataSet->Tables["Score"];
DataColumn^ firstNameColumn2 = ScoreTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn2 = ScoreTable->Columns->Add("Last Name",String::typeid);
ScoreTable->Columns->Add("Points", int::typeid);
array<DataColumn^>^ foreignKey = {firstNameColumn2, lastNameColumn2};
ScoreTable->Constraints->Add("PlayerFK", primaryKey, foreignKey);
// (Same as establish a data relation)
//myDataSet->Relations->Add("Player-Score", PrimaryKey, ForeignKey);
}

</source>

==Add primary key constraints to DataTable==

<source lang="csharp">
#include "stdafx.h"
using namespace System;
using namespace System::Data;
void main()
{
DataSet^ myDataSet = gcnew DataSet("Game Data");
myDataSet->Tables->Add("Player");
myDataSet->Tables->Add("Score");
DataTable^ playerTable = myDataSet->Tables["Player"];
DataColumn^ firstNameColumn1 = playerTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn1 = playerTable->Columns->Add("Last Name",String::typeid);
playerTable->Columns->Add("Email", String::typeid);
array<DataColumn^>^ primaryKey = {firstNameColumn1, lastNameColumn1};
playerTable->Constraints->Add("PlayerPK", primaryKey, true);
// (Same as creating the composite primary key)
//playerTable->PrimaryKey = PrimaryKey;
}

</source>

==Data Relations==

<source lang="csharp">
#include "stdafx.h"
using namespace System;
using namespace System::Data;
void main()
{
DataSet^ myDataSet = gcnew DataSet("Game Data");
DataTable^ playerTable = myDataSet->Tables->Add("Player");
DataTable^ scoreTable = myDataSet->Tables->Add("Score");
DataColumn^ firstNameColumn1 = playerTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn1 = playerTable->Columns->Add("Last Name",String::typeid);
playerTable->Columns->Add("Email", String::typeid);
array<DataColumn^>^ primaryKey = {firstNameColumn1, lastNameColumn1};
playerTable->PrimaryKey = primaryKey;
DataColumn^ firstNameColumn2 = scoreTable->Columns->Add("First Name",String::typeid);
DataColumn^ lastNameColumn2 = scoreTable->Columns->Add("Last Name",String::typeid);
scoreTable->Columns->Add("Points", int::typeid);
array<DataColumn^>^ foreignKey = {firstNameColumn2, lastNameColumn2};
myDataSet->Relations->Add("Player-Score", primaryKey, foreignKey);
myDataSet->Tables["Score"]->Constraints->Add("Unique",foreignKey, true);
}

</source>

==Table Mapping==

<source lang="csharp">
#include "stdafx.h"
using namespace System;
using namespace System::Data;
using namespace System::Data::Common;
using namespace System::Data::OleDb;
using namespace System::Data::SqlClient;
void main()
{
OleDbConnection^ myConnection = nullptr;
myConnection = gcnew OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Music.mdb");
myConnection->Open();
OleDbDataAdapter^ dataAdapter = gcnew OleDbDataAdapter("SELECT * FROM Music", myConnection);
DataSet^ myDataSet = gcnew DataSet();
DataTable^ newMusicTable = myDataSet->Tables->Add("New Music");
newMusicTable->Columns->Add("Title");
newMusicTable->Columns->Add("Duration");
DataTableMapping^ myMapping = dataAdapter->TableMappings->Add("Music", "New Music");
myMapping->ColumnMappings->Add("Title", "Title");
myMapping->ColumnMappings->Add("Duration", "Duration");
dataAdapter->MissingSchemaAction = MissingSchemaAction::Ignore;
dataAdapter->Fill(myDataSet, "Music");
for ( int i = 0; i < newMusicTable->Rows->Count; i++ ){
Console::WriteLine(newMusicTable->Rows[i]["Title"]);
Console::WriteLine(newMusicTable->Rows[i]["Duration"]);
}
myConnection->Close();
}

</source>

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Visual C++ .NET/Database ADO.net/DataTable - История изменений

в 15:31, 26 мая 2010

Admin: 1 версия