一、填充dataset
1 class Program
2 {
3 private static string constr = "server=.;database=northwnd;integrated security=sspi";
4 static void Main(string[] args)
5 {
6 string sql = "select contactname,companyname from customers";
7 using (SqlConnection con=new SqlConnection(constr))
8 {
9 SqlDataAdapter sda = new SqlDataAdapter(sql, constr);
10 DataSet ds = new DataSet();
11 sda.Fill(ds, "Customers");
12 foreach (DataRow row in ds.Tables["Customers"].Rows)
13 Console.WriteLine("‘{0}‘ from {1}",
14 row[0],
15 row[1]);
16
17 con.Close();
18 }
19 Console.ReadLine();
20 }
21 }
二、dataset主外键关系
1 class Program
2 {
3 private static string constr = "server=.;database=northwnd;integrated security=sspi";
4 static void Main(string[] args)
5 {
6 string select = "SELECT * FROM Products";
7 string sel2 = "SELECT * FROM Categories";
8 using (SqlConnection con=new SqlConnection(constr))
9 {
10 SqlDataAdapter da = new SqlDataAdapter(select, con);
11
12 DataSet ds = new DataSet();
13
14
15 ManufactureProductDataTable(ds);
16
17 da.Fill(ds, "Products");
18
19 foreach (DataRow row in ds.Tables["Products"].Rows)
20 Console.WriteLine("‘{0}‘ from {1}",
21 row[0],
22 row[1]);
23
24 SqlDataAdapter da2 = new SqlDataAdapter(sel2, con);
25
26
27 ManufactureCategoryTable(ds);
28
29 da2.Fill(ds, "Categories");
30
31 AddForeignKeyConstraint(ds);
32
33 con.Close();
34 }
35 }
36 public static void ManufactureProductDataTable(DataSet ds)
37 {
38 DataTable products = new DataTable("Products");
39 products.Columns.Add(new DataColumn("ProductID", typeof(int)));
40 products.Columns.Add(new DataColumn("ProductName", typeof(string)));
41 products.Columns.Add(new DataColumn("SupplierID", typeof(int)));
42 products.Columns.Add(new DataColumn("CategoryID", typeof(int)));
43 products.Columns.Add(new DataColumn("QuantityPerUnit", typeof(string)));
44 products.Columns.Add(new DataColumn("UnitPrice", typeof(decimal)));
45 products.Columns.Add(new DataColumn("UnitsInStock", typeof(short)));
46 products.Columns.Add(new DataColumn("UnitsOnOrder", typeof(short)));
47 products.Columns.Add(new DataColumn("ReorderLevel", typeof(short)));
48 products.Columns.Add(new DataColumn("Discontinued", typeof(bool)));
49
50 ManufacturePrimaryKey(products);
51
52 ds.Tables.Add(products);
53 }
54 public static void ManufacturePrimaryKey(DataTable dt)
55 {
56 DataColumn[] pk = new DataColumn[1];
57 pk[0] = dt.Columns["ProductID"];
58 dt.Constraints.Add(new UniqueConstraint("PK_Products", pk[0]));
59 dt.PrimaryKey = pk;
60 }
61 public static void ManufactureCategoryTable(DataSet ds)
62 {
63 DataTable categories = new DataTable("Categories");
64
65 categories.Columns.Add(new DataColumn("CategoryID", typeof(int)));
66 categories.Columns.Add(new DataColumn("CategoryName", typeof(string)));
67 categories.Columns.Add(new DataColumn("Description", typeof(string)));
68
69 categories.Constraints.Add(new UniqueConstraint("PK_Categories", categories.Columns["CategoryID"]));
70
71 categories.PrimaryKey = new DataColumn[1] { categories.Columns["CategoryID"] };
72
73 ds.Tables.Add(categories);
74
75 }
76 public static void AddForeignKeyConstraint(DataSet ds)
77 {
78 DataColumn parent = ds.Tables["Categories"].Columns["CategoryID"];
79 DataColumn child = ds.Tables["Products"].Columns["CategoryID"];
80
81 ForeignKeyConstraint fk = new ForeignKeyConstraint("FK_Product_CategoryID", parent, child);
82
83 fk.UpdateRule = Rule.Cascade;
84 fk.DeleteRule = Rule.SetNull;
85
86 // Create the constraint
87 // If this fails, you have a row in the products table with no associated category
88 ds.Tables["Products"].Constraints.Add(fk);
89
90 }
91 }
三、数据关联关系
1 class Program
2 {
3 static void Main(string[] args)
4 {
5
6 DataSet ds = CreateDataSetWithRelationships();
7
8
9 DataRow aBuilding = ds.Tables["Building"].NewRow();
10
11 aBuilding["BuildingID"] = 1;
12 aBuilding["Name"] = "The Lowry";
13
14 ds.Tables["Building"].Rows.Add(aBuilding);
15
16
17 DataRow aRoom = ds.Tables["Room"].NewRow();
18
19 aRoom["RoomID"] = 1;
20 aRoom["Name"] = "Reception";
21 aRoom["BuildingID"] = 1;
22
23 ds.Tables["Room"].Rows.Add(aRoom);
24
25
26 aRoom = ds.Tables["Room"].NewRow();
27 aRoom["RoomID"] = 2;
28 aRoom["Name"] = "The Modern Art Gallery";
29 aRoom["BuildingID"] = 1;
30
31 ds.Tables["Room"].Rows.Add(aRoom);
32
33
34 foreach (DataRow theBuilding in ds.Tables["Building"].Rows)
35 {
36 DataRow[] children = theBuilding.GetChildRows("Rooms");
37 int roomCount = children.Length;
38
39 Console.WriteLine("Building {0} contains {1} room{2}",
40 theBuilding["Name"],
41 roomCount,
42 roomCount > 1 ? "s" : "");
43
44
45 foreach (DataRow theRoom in children)
46 Console.WriteLine("Room: {0}", theRoom["Name"]);
47 }
48
49
50 foreach (DataRow theRoom in ds.Tables["Room"].Rows)
51 {
52 DataRow[] parents = theRoom.GetParentRows("Rooms");
53
54 foreach (DataRow theBuilding in parents)
55 Console.WriteLine("Room {0} is contained in building {1}", theRoom["Name"], theBuilding["Name"]);
56 }
57 }
58 public static DataSet CreateDataSetWithRelationships()
59 {
60 DataSet ds = new DataSet("Relationships");
61
62 ds.Tables.Add(CreateBuildingTable());
63 ds.Tables.Add(CreateRoomTable());
64
65
66 ds.Relations.Add("Rooms", ds.Tables["Building"].Columns["BuildingID"], ds.Tables["Room"].Columns["BuildingID"]);
67
68 return ds;
69 }
70 public static DataTable CreateBuildingTable()
71 {
72 DataTable aBuilding = new DataTable("Building");
73 aBuilding.Columns.Add(new DataColumn("BuildingID", typeof(int)));
74 aBuilding.Columns.Add(new DataColumn("Name", typeof(string)));
75 aBuilding.Constraints.Add(new UniqueConstraint("PK_Building", aBuilding.Columns[0]));
76 aBuilding.PrimaryKey = new DataColumn[] { aBuilding.Columns[0] };
77
78 return aBuilding;
79 }
80
81 public static DataTable CreateRoomTable()
82 {
83 DataTable aRoom = new DataTable("Room");
84 aRoom.Columns.Add(new DataColumn("RoomID", typeof(int)));
85 aRoom.Columns.Add(new DataColumn("Name", typeof(string)));
86 aRoom.Columns.Add(new DataColumn("BuildingID", typeof(int)));
87 aRoom.Constraints.Add(new UniqueConstraint("PK_Room", aRoom.Columns[0]));
88 aRoom.PrimaryKey = new DataColumn[] { aRoom.Columns[0] };
89
90 return aRoom;
91 }
92 }
时间： 2024-10-10 12:46:00