如何把DataTable对象添加到 DataSet 中

通过帮助，我们可以查出如下代码实现

示例

[ C#] 以下示例创建两个 DataTable 对象和一个 DataRelation 对象，并将这些新对象添加到 DataSet 中。然后通过调用 DataGrid.SetDataBinding 方法在 DataGrid 控件中显示这些表。 

  [C#]

// Put the next line into the Declarations section.

 private System.Data.DataSet myDataSet;

 

 private void MakeDataTables(){

    // Run all of the functions.

    MakeParentTable();

    MakeChildTable();

    MakeDataRelation();

    BindToDataGrid();

 }

 

 private void MakeParentTable(){

    // Create a new DataTable.

    System.Data.DataTable myDataTable = new DataTable("ParentTable");

    // Declare variables for DataColumn and DataRow objects.

    DataColumn myDataColumn;

    DataRow myDataRow;

 

    // Create new DataColumn, set DataType, ColumnName and add to DataTable.   

    myDataColumn = new DataColumn();

    myDataColumn.DataType = System.Type.GetType("System.Int32");

    myDataColumn.ColumnName = "id";

    myDataColumn.ReadOnly = true;

    myDataColumn.Unique = true;

    // Add the Column to the DataColumnCollection.

    myDataTable.Columns.Add(myDataColumn);

 

    // Create second column.

    myDataColumn = new DataColumn();

    myDataColumn.DataType = System.Type.GetType("System.String");

    myDataColumn.ColumnName = "ParentItem";

    myDataColumn.AutoIncrement = false;

    myDataColumn.Caption = "ParentItem";

    myDataColumn.ReadOnly = false;

    myDataColumn.Unique = false;

    // Add the column to the table.

    myDataTable.Columns.Add(myDataColumn);

 

    // Make the ID column the primary key column.

    DataColumn[] PrimaryKeyColumns = new DataColumn[1];

    PrimaryKeyColumns[0] = myDataTable.Columns["id"];

    myDataTable.PrimaryKey = PrimaryKeyColumns;

 

    // Instantiate the DataSet variable.

    myDataSet = new DataSet();

    // Add the new DataTable to the DataSet.

    myDataSet.Tables.Add(myDataTable);

 

    // Create three new DataRow objects and add them to the DataTable

    for (int i = 0; i<= 2; i++){

       myDataRow = myDataTable.NewRow();

       myDataRow["id"] = i;

       myDataRow["ParentItem"] = "ParentItem " + i;

       myDataTable.Rows.Add(myDataRow);

    }

 }

 

 private void MakeChildTable(){

    // Create a new DataTable.

    DataTable myDataTable = new DataTable("childTable");

    DataColumn myDataColumn;

    DataRow myDataRow;

 

    // Create first column and add to the DataTable.

    myDataColumn = new DataColumn();

    myDataColumn.DataType= System.Type.GetType("System.Int32");

    myDataColumn.ColumnName = "ChildID";

    myDataColumn.AutoIncrement = true;

    myDataColumn.Caption = "ID";

    myDataColumn.ReadOnly = true;

    myDataColumn.Unique = true;

    // Add the column to the DataColumnCollection.

    myDataTable.Columns.Add(myDataColumn);

 

    // Create second column.

    myDataColumn = new DataColumn();

    myDataColumn.DataType= System.Type.GetType("System.String");

    myDataColumn.ColumnName = "ChildItem";

    myDataColumn.AutoIncrement = false;

    myDataColumn.Caption = "ChildItem";

    myDataColumn.ReadOnly = false;

    myDataColumn.Unique = false;

    myDataTable.Columns.Add(myDataColumn);

 

    // Create third column.

    myDataColumn = new DataColumn();

    myDataColumn.DataType= System.Type.GetType("System.Int32");

    myDataColumn.ColumnName = "ParentID";

    myDataColumn.AutoIncrement = false;

    myDataColumn.Caption = "ParentID";

    myDataColumn.ReadOnly = false;

    myDataColumn.Unique = false;

    myDataTable.Columns.Add(myDataColumn);

 

    myDataSet.Tables.Add(myDataTable);

    // Create three sets of DataRow objects, five rows each, and add to DataTable.

    for(int i = 0; i <= 4; i ++){

       myDataRow = myDataTable.NewRow();

       myDataRow["childID"] = i;

       myDataRow["ChildItem"] = "Item " + i;

       myDataRow["ParentID"] = 0 ;

       myDataTable.Rows.Add(myDataRow);

    }

    for(int i = 0; i <= 4; i ++){

       myDataRow = myDataTable.NewRow();

       myDataRow["childID"] = i + 5;

       myDataRow["ChildItem"] = "Item " + i;

       myDataRow["ParentID"] = 1 ;

       myDataTable.Rows.Add(myDataRow);

    }

    for(int i = 0; i <= 4; i ++){

       myDataRow = myDataTable.NewRow();

       myDataRow["childID"] = i + 10;

       myDataRow["ChildItem"] = "Item " + i;

       myDataRow["ParentID"] = 2 ;

       myDataTable.Rows.Add(myDataRow);

    }

 }

 

 private void MakeDataRelation(){

    // DataRelation requires two DataColumn (parent and child) and a name.

    DataRelation myDataRelation;

    DataColumn parentColumn;

    DataColumn childColumn;

    parentColumn = myDataSet.Tables["ParentTable"].Columns["id"];

    childColumn = myDataSet.Tables["ChildTable"].Columns["ParentID"];

    myDataRelation = new DataRelation("parent2Child", parentColumn, childColumn);

    myDataSet.Tables["ChildTable"].ParentRelations.Add(myDataRelation);

 }

 

 private void BindToDataGrid(){

    // Instruct the DataGrid to bind to the DataSet, with the

    // ParentTable as the topmost DataTable.

    dataGrid1.SetDataBinding(myDataSet,"ParentTable");

 }

但是在实际的开发过程中，我们一般是通过数据库读取数据，然后放到DataSet中，下面我使用演示如何通过连接数据实现

private DataSet myds;

myds=new DataSet();

   SqlDataBase  SqlDB=new SqlDataBase(DSN);

   string strsql=" select * from A ";

   System.Data.DataSet ds=SqlDB.CreateSet(strsql,"A");

            DataTable dt;

   dt=ds.Tables[0].Clone();

   myds.Tables.Add(dt);

   string strsql1=" select * from B";

   System.Data.DataSet ds1=SqlDB.CreateSet(strsql1,"B");

            DataTable dt1;

   dt1=ds1.Tables[0].Clone();

   myds.Tables.Add(dt1);

   SqlDB.CloseConnection();

   myds.Merge(ds.Tables[0]);

   myds.Merge(ds1.Tables[0]);

   this.DataGrid1.DataSource=myds;

  

   this.DataGrid1.DataBind();

   this.DataGrid2.DataSource=myds.Tables[1];

   this.DataGrid2.DataBind();