using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace DataSetHelper
{
public class DataSetHelper
{
public DataSet ds;
private System.Collections.ArrayList m_FieldInfo; private string m_FieldList;
private class FieldInfo
{
public string RelationName;
public string FieldName; //source table field name
public string FieldAlias; //destination table field name
}
public DataSetHelper(ref DataSet DataSet)
{
ds = DataSet;
}
public DataSetHelper()
{
ds = null;
}
private void ParseFieldList(string FieldList, bool AllowRelation)
{
/*
* This code parses FieldList into FieldInfo objects and then
* adds them to the m_FieldInfo private member
*
* FieldList systax: [relationname.]fieldname[ alias], ...
*/
if (m_FieldList == FieldList) return;
m_FieldInfo = new System.Collections.ArrayList();
m_FieldList = FieldList;
FieldInfo Field; string[] FieldParts;
string[] Fields = FieldList.Split(',');
int i;
for (i = 0; i <= Fields.Length - 1; i++)
{
Field = new FieldInfo();
//parse FieldAlias
FieldParts = Fields[i].Trim().Split(' ');
switch (FieldParts.Length)
{
case 1:
//to be set at the end of the loop
break;
case 2:
Field.FieldAlias = FieldParts[1];
break;
default:
throw new Exception("Too many spaces in field definition: '" + Fields[i] + "'.");
}
//parse FieldName and RelationName
FieldParts = FieldParts[0].Split('.');
switch (FieldParts.Length)
{
case 1:
Field.FieldName = FieldParts[0];
break;
case 2:
if (AllowRelation == false)
throw new Exception("Relation specifiers not permitted in field list: '" + Fields[i] + "'.");
Field.RelationName = FieldParts[0].Trim();
Field.FieldName = FieldParts[1].Trim();
break;
default:
throw new Exception("Invalid field definition: " + Fields[i] + "'.");
}
if (Field.FieldAlias == null)
Field.FieldAlias = Field.FieldName;
m_FieldInfo.Add(Field);
}
}
public DataTable CreateJoinTable(string TableName, DataTable SourceTable, string FieldList)
{
/*
* Creates a table based on fields of another table and related parent tables
*
* FieldList syntax: [relationname.]fieldname[ alias][,[relationname.]fieldname[ alias]]...
*/
if (FieldList == null)
{
throw new ArgumentException("You must specify at least one field in the field list.");
//return CreateTable(TableName, SourceTable);
}
else
{
DataTable dt = new DataTable(TableName);
ParseFieldList(FieldList, true);
foreach (FieldInfo Field in m_FieldInfo)
{
if (Field.RelationName == null)
{
DataColumn dc = SourceTable.Columns[Field.FieldName];
dt.Columns.Add(dc.ColumnName, dc.DataType, dc.Expression);
}
else
{
DataColumn dc = SourceTable.ParentRelations[Field.RelationName].ParentTable.Columns[Field.FieldName];
dt.Columns.Add(dc.ColumnName, dc.DataType, dc.Expression);
}
}
if (ds != null)
ds.Tables.Add(dt);
return dt;
}
}
public void InsertJoinInto(DataTable DestTable, DataTable SourceTable,
string FieldList, string RowFilter, string Sort)
{
/*
* Copies the selected rows and columns from SourceTable and inserts them into DestTable
* FieldList has same format as CreatejoinTable
*/
if (FieldList == null)
{
throw new ArgumentException("You must specify at least one field in the field list.");
//InsertInto(DestTable, SourceTable, RowFilter, Sort);
}
else
{
ParseFieldList(FieldList, true);
DataRow[] Rows = SourceTable.Select(RowFilter, Sort);
foreach (DataRow SourceRow in Rows)
{
DataRow DestRow = DestTable.NewRow();
foreach (FieldInfo Field in m_FieldInfo)
{
if (Field.RelationName == null)
{
DestRow[Field.FieldName] = SourceRow[Field.FieldName];
}
else
{
DataRow ParentRow = SourceRow.GetParentRow(Field.RelationName);
DestRow[Field.FieldName] = ParentRow[Field.FieldName];
}
}
DestTable.Rows.Add(DestRow);
}
}
}
public DataTable SelectJoinInto(string TableName, DataTable SourceTable, string FieldList, string RowFilter, string Sort)
{
/*
* Selects sorted, filtered values from one DataTable to another.
* Allows you to specify relationname.fieldname in the FieldList to include fields from
* a parent table. The Sort and Filter only apply to the base table and not to related tables.
*/
DataTable dt = CreateJoinTable(TableName, SourceTable, FieldList);
InsertJoinInto(dt, SourceTable, FieldList, RowFilter, Sort);
return dt;
}
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
调用 winform
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using DataSetHelper;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
DataSet ds; DataSetHelper.DataSetHelper dsHelper;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
ds = new DataSet();
dsHelper = new DataSetHelper.DataSetHelper(ref ds);
//Create source tables
DataTable dt = new DataTable("Employees");
dt.Columns.Add("EmployeeID", Type.GetType("System.Int32"));
dt.Columns.Add("FirstName", Type.GetType("System.String"));
dt.Columns.Add("LastName", Type.GetType("System.String"));
dt.Columns.Add("BirthDate", Type.GetType("System.DateTime"));
dt.Columns.Add("JobTitle", Type.GetType("System.String"));
dt.Columns.Add("DepartmentID", Type.GetType("System.Int32"));
dt.Rows.Add(new object[] { 1, "Tommy", "Hill", new DateTime(1970, 12, 31), "Manager", 42 });
dt.Rows.Add(new object[] { 2, "Brooke", "Sheals", new DateTime(1977, 12, 31), "Manager", 23 });
dt.Rows.Add(new object[] { 3, "Bill", "Blast", new DateTime(1982, 5, 6), "Sales Clerk", 42 });
dt.Rows.Add(new object[] { 1, "Kevin", "Kline", new DateTime(1978, 5, 13), "Sales Clerk", 42 });
dt.Rows.Add(new object[] { 1, "Martha", "Seward", new DateTime(1976, 7, 4), "Sales Clerk", 23 });
dt.Rows.Add(new object[] { 1, "Dora", "Smith", new DateTime(1985, 10, 22), "Trainee", 42 });
dt.Rows.Add(new object[] { 1, "Elvis", "Pressman", new DateTime(1972, 11, 5), "Manager", 15 });
dt.Rows.Add(new object[] { 1, "Johnny", "Cache", new DateTime(1984, 1, 23), "Sales Clerk", 15 });
dt.Rows.Add(new object[] { 1, "Jean", "Hill", new DateTime(1979, 4, 14), "Sales Clerk", 42 });
dt.Rows.Add(new object[] { 1, "Anna", "Smith", new DateTime(1985, 6, 26), "Trainee", 15 });
ds.Tables.Add(dt);
dt = new DataTable("Departments");
dt.Columns.Add("DepartmentID", Type.GetType("System.Int32"));
dt.Columns.Add("DepartmentName", Type.GetType("System.String"));
dt.Rows.Add(new object[] { 15, "Men's Clothing" });
dt.Rows.Add(new object[] { 23, "Women's Clothing" });
dt.Rows.Add(new object[] { 42, "Children's Clothing" });
ds.Tables.Add(dt);
ds.Relations.Add("DepartmentEmployee", ds.Tables["Departments"].Columns["DepartmentID"],
ds.Tables["Employees"].Columns["DepartmentID"]);
}
private void btnCreateJoin_Click(object sender, EventArgs e)
{
dsHelper.CreateJoinTable("EmpDept", ds.Tables["Employees"],
"FirstName FName,LastName LName,BirthDate,DepartmentEmployee.DepartmentName Department");
//dataGrid1.SetDataBinding(ds, "EmpDept");
}
private void btnSelectJoinInto_Click(object sender, EventArgs e)
{
dsHelper.SelectJoinInto("EmpDept2", ds.Tables["Employees"],
"FirstName,LastName,BirthDate BDate,DepartmentEmployee.DepartmentName Department",
"JobTitle='Manager'", "DepartmentID");
//dataGrid1.SetDataBinding(ds, "EmpDept2");
}
private void btnInsertJoinInto_Click(object sender, EventArgs e)
{
dsHelper.InsertJoinInto(ds.Tables["EmpDept"], ds.Tables["Employees"],
"FirstName FName,LastName LName,BirthDate,DepartmentEmployee.DepartmentName Department",
"JobTitle='Sales Clerk'", "DepartmentID");
//dataGrid1.SetDataBinding(ds, "EmpDept");
}
}
}