linq入门(2) -- 调用存储过程进行查询,删除,更新，新增

本来linq是可以调用Sql语句来进行数据库的四步操作的，但是我对Sql语句写在类里面，非常反感，所以不打算写这个体会了，调用Sql语句的方法可以参看webabcd的步步为营VS 2008 + .NET 3.5(9) - DLINQ(LINQ to SQL)之执行SQL语句的添加、查询、更新和删除 这篇。
本篇，关注的是linq调用存储过程来完成数据库的四步操作(查询,删除,更新，新增)。
数据库仍然是Northwind，数据源是表Customers
1). 首先创建一个网站,添加Linq to Sql类，名称为Northwind.dbml;
2). 打开Visual Studio的服务器资源管理器，选择数据连接-添加连接，引入Northwind数据库，展开，将Customers表拖到Northwind.dbml，这样就完成了创建Customers对象；
3). 创建查询,删除,更新,新增 Customers 的存储过程，代码如下:

查询 Customers 1---------------------------------------------------------------------------
2--Procedure Name: [dbo].[selCustomers]
3--Note : get Customers
4--Created By : Tom
5--Created Date : 2008-5-28
6---------------------------------------------------------------------------
7CREATE PROCEDURE [dbo].[selCustomers]
8(
9 @ncCoustomerID NVARCHAR(5) = NULL,
10 @nvcCountry NVARCHAR(15) = NULL
11)
12
13AS
14 IF @ncCoustomerID IS NULL OR @ncCoustomerID = ''
15 SET @ncCoustomerID = NULL
16
17 IF @nvcCountry IS NULL OR @nvcCountry = ''
18 SET @nvcCountry = NULL
19
20 SELECT *
21 FROM CUSTOMERS
22 WHERE CUSTOMERID LIKE ISNULL(@ncCoustomerID, '%')
23 AND COUNTRY LIKE ISNULL(@nvcCountry, '%')
24RETURN



删除 Customers 1--------------------------------------------------------------------------
2--Procedure Name : [dbo].[delCustomers]
3--Note : delete Customer
4--Created By : Tom
5--Created Date : 2008-5-28
6--------------------------------------------------------------------------
7CREATE PROCEDURE [dbo].[delCustomers]
8(
9 @ncCustomerID NCHAR(5)
10)
11
12AS
13 DELETE CUSTOMERS
14 WHERE CUSTOMERID = @ncCUSTOMERID
15RETURN



更新 Customer 1---------------------------------------------------------------------------
2--Procedure Name : [dbo].[updCustomers]
3--Note : modify Customer
4--Created By : Tom
5--Created Date : 2008-5-28
6---------------------------------------------------------------------------
7CREATE PROCEDURE [dbo].[updCustomers]
8(
9 @ncCustomerID NCHAR(5),
10 @nvcCompanyName NVARCHAR(40),
11 @nvcAddress NVARCHAR(60),
12 @intReturnValue INT OUTPUT
13)
14
15AS
16 --不返回受影响的行
17 SET NOCOUNT ON
18
19 --更新指定的Customers
20 UPDATE CUSTOMERS
21 SET COMPANYNAME = @nvcCompanyName,
22 ADDRESS = @nvcAddress
23 WHERE CUSTOMERID = @ncCustomerID
24
25 IF @@ERROR <> 0
26 BEGIN
27 --如果更新发生异常，返回-1
28 SET @intReturnValue = -1
29 RETURN
30 END
31
32RETURN
33



新增 Customer 1---------------------------------------------------------------------------
2--Procedure Name : [dbo].[insCustomers]
3--Note : add Customer
4--Created By : Tom
5--Created Date : 2008-5-28
6---------------------------------------------------------------------------
7CREATE PROCEDURE [dbo].[insCustomers]
8(
9 @ncCustomerID NCHAR(5),
10 @nvcCompanyName NVARCHAR(40),
11 @nvcContactName NVARCHAR(30) = NULL,
12 @nvcContactTitle NVARCHAR(30) = NULL,
13 @nvcAddress NVARCHAR(60) = NULL,
14 @nvcCity NVARCHAR(15) = NULL,
15 @nvcRegion NVARCHAR(15) = NULL,
16 @nvcPostalCode NVARCHAR(10) = NULL,
17 @nvcCountry NVARCHAR(15) = NULL,
18 @nvcPhone NVARCHAR(24) = NULL,
19 @nvcFax NVARCHAR(24) = NULL,
20 @intReturnValue INT OUTPUT
21)
22AS
23 --新增Customers行
24 INSERT INTO [dbo].[CUSTOMERS]
25 ([CUSTOMERID],
26 [COMPANYNAME],
27 [CONTACTNAME],
28 [CONTACTTITLE],
29 [ADDRESS],
30 [CITY],
31 [REGION],
32 [POSTALCODE],
33 [COUNTRY],
34 [PHONE],
35 [FAX])
36 VALUES
37 (@ncCustomerID,
38 @nvcCompanyName,
39 @nvcContactName,
40 @nvcContactTitle,
41 @nvcAddress,
42 @nvcCity,
43 @nvcRegion,
44 @nvcPostalCode,
45 @nvcCountry,
46 @nvcPhone,
47 @nvcFax)
48
49 IF @@ERROR <> 0
50 BEGIN
51 --如果更新发生异常，返回-1
52 SET @intReturnValue = -1
53 RETURN
54 END
55RETURN
56

4). 打开Visual Studio2008的服务器资源管理器，展开Northwind数据库的存储过程目录，将上叙四个存储过程依次拖入到打开的Northwind.dbml右侧方法区，查看引入的四个存储过程的属性，修改其Name名为"GetCustomers","DeleteCustomers","UpdateCustomers","InsertCustomers",如下图所示：

5). 新建一个页面:LinqBySP.aspx,页面代码(只列出form部分)如下：

LinqBySP
1<form id="form1" runat="server">
2 <div>
3 <h4>
4 查询</h4>
5 <table>
6 <tr>
7 <td>
8 Customer ID:
9 </td>
10 <td>
11 <asp:DropDownList ID="drpCustomerID" runat="server">
12 </asp:DropDownList>
13 </td>
14 <td>
15 Country:
16 </td>
17 <td>
18 <asp:TextBox ID="txtCountry" runat="server">
19 </asp:TextBox>
20 </td>
21 </tr>
22 <tr>
23 <td colspan="2">
24 <asp:Button ID="btnSelect" runat="server" Text="Search" OnClick="btnSelect_Click" />
25      
26 <asp:Button ID="btnCancel" runat="server" Text="Cancel" OnClick="btnCancel_Click" />
27
28 </td>
29 </tr>
30 </table>
31 </div>
32 <div>
33 <h4>
34 新增</h4>
35 <table>
36 <tr>
37 <td>
38 Customer ID:
39 </td>
40 <td>
41 <asp:TextBox ID="txtCustomerID" runat="server">
42 </asp:TextBox>
43 </td>
44 </tr>
45 <tr>
46 <td>
47 Company Name:
48 </td>
49 <td>
50 <asp:TextBox ID="txtCompanyName" runat="server">
51 </asp:TextBox>
52 </td>
53 </tr>
54 <tr>
55 <td colspan="2">
56 <asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="btnAdd_Click" />
57 </td>
58 </tr>
59 </table>
60 </div>
61 <div>
62 <h4>
63 显示 更新 删除</h4>
64 <asp:GridView ID="gvSelLinQ" runat="server" AllowPaging="True" OnPageIndexChanging="gvSelLinq_PageIndexChanging"
65 OnRowDeleting="gvSelLinQ_RowDeleting" OnRowUpdating="gvSelLinQ_RowUpdating" BackColor="White"
66 BorderColor="#3366CC" BorderStyle="None" BorderWidth="1px" CellPadding="4" OnRowEditing="gvSelLinQ_RowEditing"
67 OnRowCancelingEdit="gvSelLinQ_RowCancelingEdit" DataKeyNames="CustomerID">
68 <PagerSettings Position="TopAndBottom" />
69 <FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
70 <RowStyle BackColor="White" ForeColor="#003399" />
71 <Columns>
72 <asp:CommandField ShowEditButton="True" />
73 <asp:CommandField ShowDeleteButton="True" />
74 </Columns>
75 <PagerStyle BackColor="#99CCCC" ForeColor="#003399" HorizontalAlign="Left" />
76 <SelectedRowStyle BackColor="#009999" Font-Bold="True" ForeColor="#CCFF99" />
77 <HeaderStyle BackColor="#003399" Font-Bold="True" ForeColor="#CCCCFF" />
78 </asp:GridView>
79 </div>
80 </form>

后台代码，如下：

LinqBySP 主要代码 1public partial class LinqBySP : System.Web.UI.Page
2 {
3 /**//// <summary>
4 /// Linq to Sql 类:Norwind DataContext 初始化
5 /// </summary>
6 NorthwindDataContext northwind = new NorthwindDataContext();
7
8 /**//// <summary>
9 /// 页面初始化
10 /// </summary>
11 /// <param name="sender"></param>
12 /// <param name="e"></param>
13 protected void Page_Load(object sender, EventArgs e)
14 {
15 if (!IsPostBack)
16 {
17 BindDDL();
18 BindGrid();
19 }
20 }
21
22 /**//// <summary>
23 /// 绑定DropDownList
24 /// </summary>
25 private void BindDDL()
26 {
27 string customerID = string.Empty, country = string.Empty;
28 var c = getCustomers(customerID, country).Select(t => t.CustomerID);
29
30 drpCustomerID.DataSource = c;
31 drpCustomerID.DataBind();
32
33 drpCustomerID.Items.Insert(0, "");
34 }
35
36 /**//// <summary>
37 /// 绑定GridView
38 /// </summary>
39 private void BindGrid()
40 {
41 string customerID = string.Empty, country = string.Empty;
42 customerID = drpCustomerID.SelectedValue.Trim();
43 country = txtCountry.Text.Trim();
44 var c = getCustomers(customerID, country);
45
46 gvSelLinQ.DataSource = c;
47 gvSelLinQ.DataBind();
48 }
49
50 private IEnumerable<Customers> getCustomers(string customerID, string country)
51 {
52 var c = northwind.GetCustomers(customerID, country);
53 return (IEnumerable<Customers>)c;
54 }
55
56 /**//// <summary>
57 /// 根据指定的查询条件获取Customers实体集对象指定的实体
58 /// </summary>
59 /// <param name="sender"></param>
60 /// <param name="e"></param>
61 protected void btnSelect_Click(object sender, EventArgs e)
62 {
63 BindGrid();
64 }
65
66 /**//// <summary>
67 /// 撤销当前查询条件，页面初始化
68 /// </summary>
69 /// <param name="sender"></param>
70 /// <param name="e"></param>
71 protected void btnCancel_Click(object sender, EventArgs e)
72 {
73 //初始化当前查询条件
74 drpCustomerID.SelectedValue = string.Empty;
75 txtCountry.Text = string.Empty;
76
77 //重新绑定GridView
78 BindGrid();
79 }
80
81 /**//// <summary>
82 /// 新增Customers
83 /// </summary>
84 /// <param name="sender"></param>
85 /// <param name="e"></param>
86 protected void btnAdd_Click(object sender, EventArgs e)
87 {
88 //声明变量
89 string customerID = string.Empty, companyname = string.Empty, contactname = string.Empty, contacttitle = string.Empty, address = string.Empty, city = string.Empty;
90 string region = string.Empty, postalcode = string.Empty, country = string.Empty, phone = string.Empty, fax = string.Empty;
91
92 //声明返回值
93 int? returnValue = null;
94
95 //获取新增的Customers实体的数据
96 customerID = txtCustomerID.Text.Trim();
97 companyname = txtCompanyName.Text.Trim();
98
99 //调用Linq to sql类的InsertCustomers方法来新增Customers实体
100 northwind.InsertCustomers(customerID, companyname, contactname, contacttitle, address, city, region, postalcode, country, phone, fax, ref returnValue);
101
102 //重新绑定DropDownList和GridView
103 BindDDL();
104 BindGrid();
105 }
106
107 GridView 事件#region GridView 事件
108 /**//// <summary>
109 /// GridView分页
110 /// </summary>
111 /// <param name="sender"></param>
112 /// <param name="e"></param>
113 protected void gvSelLinq_PageIndexChanging(object sender, GridViewPageEventArgs e)
114 {
115 gvSelLinQ.PageIndex = e.NewPageIndex;
116 BindGrid();
117 }
118
119 /**//// <summary>
120 /// 编辑 GridView
121 /// </summary>
122 /// <param name="sender"></param>
123 /// <param name="e"></param>
124 protected void gvSelLinQ_RowEditing(object sender, GridViewEditEventArgs e)
125 {
126 gvSelLinQ.EditIndex = e.NewEditIndex;
127 BindGrid();
128 }
129
130 /**//// <summary>
131 /// 编辑 GridView 撤销
132 /// </summary>
133 /// <param name="sender"></param>
134 /// <param name="e"></param>
135 protected void gvSelLinQ_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
136 {
137 gvSelLinQ.EditIndex = -1;
138 BindGrid();
139 }
140
141 /**//// <summary>
142 /// 更新 Customers
143 /// </summary>
144 /// <param name="sender"></param>
145 /// <param name="e"></param>
146 protected void gvSelLinQ_RowUpdating(object sender, GridViewUpdateEventArgs e)
147 {
148 //变量
149 string customerID = string.Empty, companyname = string.Empty, address = string.Empty;
150
151 //返回值
152 int? returnValue = null; //为了数据操作异常而定义，这里我就不写了，不然又会写一大堆
153
154 //变量赋值
155 customerID = gvSelLinQ.DataKeys[e.RowIndex].Value.ToString().Trim();
156 companyname = ((TextBox)gvSelLinQ.Rows[e.RowIndex].Cells[3].Controls[0]).Text.Trim();
157 address = ((TextBox)gvSelLinQ.Rows[e.RowIndex].Cells[6].Controls[0]).Text.Trim();
158
159 //调用Norwind DataContext类的UpdateCustomers方法，更新指定的Customers对象
160 northwind.UpdateCustomers(customerID, companyname, address, ref returnValue);
161
162 //重新绑定GridView
163 gvSelLinQ.EditIndex = -1;
164 BindGrid();
165 }
166
167 /**//// <summary>
168 /// 删除 Customers
169 /// </summary>
170 /// <param name="sender"></param>
171 /// <param name="e"></param>
172 protected void gvSelLinQ_RowDeleting(object sender, GridViewDeleteEventArgs e)
173 {
174 string customerID = string.Empty;
175
176 //获取GridView的主键索引
177 customerID = gvSelLinQ.DataKeys[e.RowIndex].Value.ToString().Trim();
178
179 //调用Norwind DataContext类的DeleteCustomers方法，删除指定的Customers对象
180 northwind.DeleteCustomers(customerID);
181
182 //重新绑定DropDownList和GridView
183 BindDDL();
184 BindGrid();
185 }
186 #endregion
187 }

好了，到这里linq第二步，调用存储过程的四步基本操作完成，thx~
后记：在引入存储过程到dbml里面的时候，GetCustomer属性的【Return Type】一定要指明是"Customers"，否则它会使用默认属性，有可能会发生问题
来自：http://www.cnblogs.com/TomToDo/archive/2008/05/29/1209602.html