DataSet key points

In a typical multiple-tier implementation, the steps for creating and refreshing a DataSet, and in turn, updating the original data are to:

1. Build and fill each DataTable in a DataSet with data from a data source using a DataAdapter.

2. Change the data in individual DataTable objects by adding, updating, or deleting DataRow objects.

3. Invoke the GetChanges method to create a second DataSet that features only the changes to the data.

4. Call the Update method of the DataAdapter, passing the second DataSet as an argument.

5. Invoke the Merge method to merge the changes from the second DataSet into the first.

6. Invoke the AcceptChanges on the DataSet. Alternatively, invoke RejectChanges to cancel the changes.

DataRelation

ds.Tables.Add(table);
                    ds.Tables.Add(detailsTableSaved);
 
                    DataColumn[] pColumns = new DataColumn[] { table.Columns["DEPT_CODE"], table.Columns["CHECK_DATE"], table.Columns["INDEX_CODE"] };
                    DataColumn[] cColumns = new DataColumn[] { detailsTableSaved.Columns["DEPT_CODE"], detailsTableSaved.Columns["CHECK_DATE"], detailsTableSaved.Columns["INDEX_CODE"] };
 
                    DataRelation tDataRelation = new DataRelation("relation_Category_Product", pColumns, cColumns);
                    ds.Relations.Add(tDataRelation);

Master and Detail Relationship

// Add data from the Customers table to the DataSet.
            SqlDataAdapter masterDataAdapter = new
                SqlDataAdapter("select * from Customers", connection);
            masterDataAdapter.Fill(data, "Customers");
 
            // Add data from the Orders table to the DataSet.
            SqlDataAdapter detailsDataAdapter = new
                SqlDataAdapter("select * from Orders", connection);
            detailsDataAdapter.Fill(data, "Orders");
 
            // Establish a relationship between the two tables.
            DataRelation relation = new DataRelation("CustomersOrders",
                data.Tables["Customers"].Columns["CustomerID"],
                data.Tables["Orders"].Columns["CustomerID"]);
            data.Relations.Add(relation);
 
            // Bind the master data connector to the Customers table.
            masterBindingSource.DataSource = data;
            masterBindingSource.DataMember = "Customers";
 
            // Bind the details data connector to the master data connector,
            // using the DataRelation name to filter the information in the
            // details table based on the current row in the master table.
            detailsBindingSource.DataSource = masterBindingSource;
            detailsBindingSource.DataMember = "CustomersOrders";

Real Example:

private void btnSearch_Click(object sender, EventArgs e)
        {
            string a = "03-8月-2014";//dtpStart.Value.ToString("yyyy/MM/dd hh:mm:ss");
            string b = "05-8月-2014";//dtpEnd.Value.ToString("yyyy-MM-dd hh:mm:ss");
            gDtNursingIndexMasterResult = getTableData.getTableData("select * from NURSING_INDEX_CHECK_MASTER where CHECK_DATE Between '" + a + "' and '" + b + "'");
            gDtNursingIndexMasterResult.Tables[0].TableName = "NURSING_INDEX_CHECK_MASTER";
            gDtNursingIndexDetailResult = getTableData.getTableData("select * from NURSING_INDEX_CHECK_DETAIL where CHECK_DATE Between '" + a + "' and '" + b + "'");
            gDtNursingIndexDetailResult.Tables[0].TableName = "NURSING_INDEX_CHECK_DETAIL";
 
            gDtNursingIndexMasterResult.Merge(gDtNursingIndexDetailResult);
 
            DataTable tblMaster = gDtNursingIndexMasterResult.Tables[0].Copy();
            DataTable tblDetail = gDtNursingIndexDetailResult.Tables[0].Copy();
 
            gDsMasterDetail.Tables.Add(tblMaster);
            gDsMasterDetail.Tables.Add(tblDetail);
 
            DataColumn[] pColumns = new DataColumn[] { tblMaster.Columns["DEPT_CODE"], tblMaster.Columns["CHECK_DATE"], tblMaster.Columns["INDEX_CODE"] };
            DataColumn[] cColumns = new DataColumn[] { tblDetail.Columns["DEPT_CODE"], tblDetail.Columns["CHECK_DATE"], tblDetail.Columns["INDEX_CODE"] };
            DataRelation tDataRelation = new DataRelation("MasterDetail", pColumns, cColumns);
            gDsMasterDetail.Relations.Add(tDataRelation);
 
            gBsMaster.DataSource = gDsMasterDetail;
            gBsMaster.DataMember = "NURSING_INDEX_CHECK_MASTER";
 
            gBsDetail.DataSource = gBsMaster;
            gBsDetail.DataMember = "MasterDetail";
            bnbSearchResult.BindingSource = gBsMaster;
 
            cmbPatBedNo.DataBindings.Add("Text", gBsMaster, "BED_NO", true);
 
        }

Generating Typed DataSets Using xsd.exe

File.WriteAllText(file\employees.xsd, DataSet2.GetXmlSchema());

c:\> xsd.exe employees.xsd /d /l:cs /n:Employees.Data

c:\> csc /target:library Employees.cs

Write and Read DataSet

file.WriteAllText(file "employees.xml", employeesTable.GetXml();