[NHibernate]存儲過程的使用（一）

 1 USE [Shop]
 2 GO
 3 
 4 --|--------------------------------------------------------------------------------
 5 --| [TB_CustomerInsert] - Insert Procedure Script for TB_Customer
 6 --|--------------------------------------------------------------------------------
 7 IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id (N'[dbo].[TB_CustomerInsert]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1) DROP PROCEDURE [dbo].[TB_CustomerInsert]
 8 GO
 9 
10 CREATE PROCEDURE [dbo].[TB_CustomerInsert]
11 (
12     @CustomerID uniqueidentifier = NEWID() OUTPUT,
13     @CustomerName nvarchar(16) = NULL,
14     @CustomerAddress nvarchar(128) = NULL,
15     @Version int
16 )
17 AS
18     SET NOCOUNT ON
19 
20     INSERT INTO [TB_Customer]
21     (
22         [CustomerID],
23         [CustomerName],
24         [CustomerAddress],
25         [Version]
26     )
27     VALUES
28     (
29         @CustomerID,
30         @CustomerName,
31         @CustomerAddress,
32         @Version
33     )
34 
35     RETURN @@Error
36 GO
37 
38 --|--------------------------------------------------------------------------------
39 --| [TB_CustomerUpdate] - Update Procedure Script for TB_Customer
40 --|--------------------------------------------------------------------------------
41 IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id (N'[dbo].[TB_CustomerUpdate]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1) DROP PROCEDURE [dbo].[TB_CustomerUpdate]
42 GO
43 
44 CREATE PROCEDURE [dbo].[TB_CustomerUpdate]
45 (
46     @CustomerID uniqueidentifier,
47     @CustomerName nvarchar(16) = NULL,
48     @CustomerAddress nvarchar(128) = NULL,
49     @Version int
50 )
51 AS
52     SET NOCOUNT ON
53     
54     UPDATE [TB_Customer]
55     SET
56         [CustomerID] = @CustomerID,
57         [CustomerName] = @CustomerName,
58         [CustomerAddress] = @CustomerAddress,
59         [Version] = @Version
60     WHERE 
61         [CustomerID] = @CustomerID
62 
63     RETURN @@Error
64 GO
65 
66 --|--------------------------------------------------------------------------------
67 --| [TB_CustomerDelete] - Update Procedure Script for TB_Customer
68 --|--------------------------------------------------------------------------------
69 IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id (N'[dbo].[TB_CustomerDelete]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1) DROP PROCEDURE [dbo].[TB_CustomerDelete]
70 GO
71 
72 CREATE PROCEDURE [dbo].[TB_CustomerDelete]
73 (
74     @CustomerID uniqueidentifier
75 )
76 AS
77     SET NOCOUNT ON
78 
79     DELETE 
80     FROM   [TB_Customer]
81     WHERE  
82         [CustomerID] = @CustomerID
83 
84     RETURN @@Error
85 GO

sql_procs_TB_Customer.sql

我使用的是sql server2012的版本，在執行腳本的時候，生成添加Customer的存儲過程，有問題

將NewId()函數去掉。修改後的存儲過程

 1 USE [Shop]
 2 GO
 3 --|--------------------------------------------------------------------------------
 4 --| [TB_CustomerInsert] - Insert Procedure Script for TB_Customer
 5 --|--------------------------------------------------------------------------------
 6 IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id (N'[dbo].[TB_CustomerInsert]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1) DROP PROCEDURE [dbo].[TB_CustomerInsert]
 7 GO
 8 
 9 CREATE PROCEDURE [dbo].[TB_CustomerInsert]
10 (
11     @CustomerID uniqueidentifier OUTPUT,
12     @CustomerName nvarchar(16) = NULL,
13     @CustomerAddress nvarchar(128) = NULL,
14     @Version int
15 )
16 AS
17     SET NOCOUNT ON
18 
19     INSERT INTO [TB_Customer]
20     (
21         [CustomerID],
22         [CustomerName],
23         [CustomerAddress],
24         [Version]
25     )
26     VALUES
27     (
28         NEWID(),
29         @CustomerName,
30         @CustomerAddress,
31         @Version
32     )
33 
34     RETURN @@Error

生成的存儲過程以下：

一個例子

在NHibernate的映射文件中，在Class元素中提供了<sql-delete>、<sql-insert>、<sql-update>元素用於刪除、新建、更新對象，注意這三個元素順序惟一，就是下圖顯示的順序，在根元素提供了<sql-query>元素用來查詢對象，下圖顯示在Class元素中的增刪改存儲過程元素。

刪除對象

修改映射文件添加存儲過程，打開Customer.hbm.xml映射文件，在Class元素下添加<sql-delete>節點，調用TB_CustomerDelete存儲過程，TB_CustomerDelete存儲過程有一個CustomerID參數，這裏用一個問號表示：

    <!--存儲過程，check參數：none/rowcount/param-->
    <sql-delete>exec TB_CustomerDelete ?</sql-delete>

測試

 1         /// <summary>
 2         /// 經過存儲過程方式刪除客戶信息
 3         /// </summary>
 4         /// <param name="customer"></param>
 5         /// <returns></returns>
 6         public bool DeleteCustomerByIDWithProcedure(Customer customer)
 7         {
 8             var session = NHibernateHelper.GetSession();
 9             using (ITransaction trans = session.BeginTransaction())
10             {
11                 try
12                 {
13                     session.Delete(customer);
14                     session.Flush();
15                     trans.Commit();
16                     return true;
17                 }
18                 catch (Exception)
19                 {
20                     trans.Rollback();
21                     throw;
22                 }
23             }
24         }

此時會有一個異常「Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [Wolfy.Shop.Domain.Entities.Customer#b0720295-9541-40b3-9994-610066224db8]」。這個錯誤是存儲過程寫法錯誤，咱們修改TB_CustomerDelete存儲過程，去掉SET NOCOUNT ON，代碼片斷以下：

 1 ALTER PROCEDURE [dbo].[TB_CustomerDelete]
 2 (
 3     @CustomerID uniqueidentifier
 4 )
 5 AS
 6     --SET NOCOUNT ON
 7 
 8     DELETE 
 9     FROM   [TB_Customer]
10     WHERE  
11         [CustomerID] = @CustomerID
12 
13     RETURN @@Error

再次運行進行測試，測試成功，查看生成的sql語句

你會發如今sql語句裏面多了一個@p1的參數。這個參數爲以前添加的Version參數，nhibernate中樂觀併發控制添加的。

如何解決？

修改存儲過程，將版本號添加上。

 1 ALTER PROCEDURE [dbo].[TB_CustomerDelete]
 2 (
 3     @CustomerID uniqueidentifier,
 4     @Version int
 5 )
 6 AS
 7     --SET NOCOUNT ON
 8 
 9     DELETE 
10     FROM   [TB_Customer]
11     WHERE  
12         [CustomerID] = @CustomerID and [Version]=@Version
13 
14     RETURN @@Error

不要忘了，此時的存儲過程有兩個參數了，版本號在映射文件中已經處理了，存儲過程當中已經幫我們自動添加上了，若是是其餘的參數可在映射文件經過"?,?..."添加多個參數。

    <!--存儲過程，check參數：none/rowcount/param-->
    <sql-delete check="rowcount" >exec TB_CustomerDelete ?</sql-delete>

再次運行進行測試，成功，生成的sql語句

exec sp_executesql N'exec TB_CustomerDelete @p0',N'@p0 uniqueidentifier,@p1 int',@p0='3727A133-C079-4DF9-B31E-7625B03F95DF',@p1=1

固然了，若是你不想使用存儲過程，也能夠直接在<sql-delete>中寫SQL語句，像這樣，照樣用。

  <sql-delete>DELETE FROM [TB_Customer] WHERE [CustomerID] = ? and [Version] =?</sql-delete>

生成的sql語句爲

exec sp_executesql N'DELETE FROM [TB_Customer] WHERE [CustomerID] = @p0 and [Version] =@p1',N'@p0 uniqueidentifier,@p1 int',@p0='64C35DEE-84D9-4C2D-ABAF-7D53631E3EAA',@p1=1