此示例 InProcessDataAccess 包含许多简单函数，这些函数演示了 SQL Server CLR 进程内数据访问提供程序的各种功能。
先决条件
若要创建并运行此项目，必须安装以下软件：
SQL Server 或 SQL Server Express。 可以从 SQL Server Express 文档和示例网站免费获取 SQL Server Express
SQL Server 开发人员网站提供的 AdventureWorks 数据库
.NET Framework SDK 2.0 或更高版本或Microsoft Visual Studio 2005 或更高版本。 可以免费获取 .NET Framework SDK。
此外，必须满足以下条件：
正在使用的 SQL Server 实例必须启用 CLR 集成。
若要启用 CLR 集成，请执行以下步骤：
启用 CLR 集成
- 执行以下 Transact-SQL 命令：
sp_configure 'clr enabled', 1GORECONFIGUREGO注释
若要启用 CLR，必须具有
ALTER SETTINGS由服务器角色成员sysadminserveradmin隐式持有的服务器级别权限。AdventureWorks 数据库必须安装在正在使用的 SQL Server 实例上。
如果你不是正在使用的 SQL Server 实例的管理员，则必须有管理员授予 CreateAssembly 权限才能完成安装。
生成示例
使用以下说明创建并运行示例：
打开 Visual Studio 或 .NET Framework 命令提示符。
如有必要，请为示例创建目录。 对于此示例，我们将使用 C：\MySample。
在 c：\MySample 中，创建
inprocda.vb（针对 Visual Basic 示例）或inprocda.cs（对于 C# 示例），并将相应的 Visual Basic 或 C# 示例代码（如下所示）复制到文件中。根据所选语言，从命令行提示符将示例代码编译到所需的程序集中。
Vbc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /target:library InProcDA.vbCsc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.XML.dll /target:library inprocda.cs
将 Transact-SQL 安装代码复制到文件中，并将其
Install.sql另存为示例目录中。如果示例安装在其他
C:\MySample\目录中，则按指示编辑该文件Install.sql以指向该位置。通过执行来部署程序集、存储过程和函数
sqlcmd -E -I -i install.sql
将 Transact-SQL 安装代码复制到文件中，并将其
test.sql另存为示例目录中。通过在命令提示符处执行以下行来测试应用程序：
sqlcmd -E -I -i test.sql
将 Transact-SQL 清理脚本复制到文件中，并将其
cleanup.sql另存为示例目录中。使用以下命令执行脚本
sqlcmd -E -I -i cleanup.sql
示例代码
下面是此示例的代码列表。
C#（编程语言）
using System;
using System.Data;
using System.Data.Sql;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using Microsoft.SqlServer.Server;
public sealed class DataAccessDemo
{
private DataAccessDemo()
{
}
/// <summary>
/// Simple example to send a message to the client.
/// </summary>
public static void SendMessage(string msg)
{
SqlContext.Pipe.Send("Message from server: " + msg);
}
/// <summary>
/// Simple example of performing data access within
/// a function
/// </summary>
/// <returns></returns>
[Microsoft.SqlServer.Server.SqlFunction(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.Read)]
public static string ReportSqlVersion()
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
//create a command from the current context
SqlCommand cmd = conn.CreateCommand();
//execute something
cmd.CommandText = "select @@version";
conn.Open();
//return results as scalar
return (string)cmd.ExecuteScalar();
}
}
/// <summary>
/// Create a result set on the fly and send it to the client.
/// </summary>
public static void SendTransientResultSet()
{
//create the metadata for the columns
Microsoft.SqlServer.Server.SqlMetaData[] columnSchema
= new Microsoft.SqlServer.Server.SqlMetaData[] {
new Microsoft.SqlServer.Server.SqlMetaData("stringcol", SqlDbType.NVarChar, 128)
};
//create a record based on that metadata
SqlDataRecord newRecord = new SqlDataRecord(columnSchema);
//populate it
newRecord.SetString(0, "Hello World!");
//send it
SqlContext.Pipe.Send(newRecord);
}
/// <summary>
/// Execute a command and send the results to the client directly.
/// </summary>
public static void ExecuteToClient()
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select @@version";
conn.Open();
SqlContext.Pipe.ExecuteAndSend(cmd);
}
}
/// <summary>
/// Execute a command and send the resultig reader to the client
/// </summary>
public static void SendReaderToClient()
{
using (SqlConnection conn = new SqlConnection("context connection=true"))
{
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select @@version";
conn.Open();
SqlDataReader rdr = cmd.ExecuteReader();
try
{
SqlContext.Pipe.Send(rdr);
}
finally
{
rdr.Close();
}
}
}
};
Visual Basic
Imports Microsoft.SqlServer.Server
Imports Microsoft.VisualBasic
Imports System
Imports System.Collections
Imports System.Data
Imports System.Data.Sql
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports System.Diagnostics
Partial Public NotInheritable Class DataAccessDemo
Private Sub New()
End Sub
''' <summary>
''' Simple example of performing data access within a function
''' </summary>
''' <returns></returns>
<SqlFunction(DataAccess:=DataAccessKind.Read)> _
Public Shared Function ReportSqlVersion() As SqlString
Using conn As New SqlConnection("context connection=true")
'create a command from the current context
Dim cmd As SqlCommand = conn.CreateCommand()
'execute something
cmd.CommandText = "SELECT @@VERSION"
conn.Open()
'return results as scalar
Return CType(cmd.ExecuteScalar(), String)
End Using
End Function
''' <summary>
''' Simple example to send a message to the client.
''' </summary>
Public Shared Sub SendMessage(ByVal msg As String)
SqlContext.Pipe.Send(("Message from server: " & msg))
End Sub
''' <summary>
''' Create a result set on the fly and send it to the client.
''' </summary>
Public Shared Sub SendTransientResultSet()
'create the metadata for the columns
Dim columnSchema() As Microsoft.SqlServer.Server.SqlMetaData _
= {New SqlMetaData("stringcol", SqlDbType.NVarChar, 128)}
'create a record based on that metadata
Dim newRecord As New SqlDataRecord(columnSchema)
'populate it
newRecord.SetString(0, "Hello World!")
'send it
SqlContext.Pipe.Send(newRecord)
End Sub
''' <summary>
''' Execute a command and send the results to the client directly.
''' </summary>
Public Shared Sub ExecuteToClient()
Using conn As New SqlConnection("context connection=true")
Dim cmd As SqlCommand = conn.CreateCommand()
cmd.CommandText = "SELECT @@VERSION"
conn.Open()
SqlContext.Pipe.ExecuteAndSend(cmd)
End Using
End Sub
''' <summary>
''' Execute a command and send the resulting reader to the client
''' </summary>
Public Shared Sub SendReaderToClient()
Using conn As New SqlConnection("context connection=true")
Dim cmd As SqlCommand = conn.CreateCommand()
cmd.CommandText = "SELECT @@VERSION"
conn.Open()
Dim rdr As SqlDataReader = cmd.ExecuteReader()
Try
SqlContext.Pipe.Send(rdr)
Finally
rdr.Close()
End Try
End Using
End Sub
End Class
这是 Transact-SQL 安装脚本（Install.sql），该脚本部署程序集并创建此示例所需的存储过程和函数。
USE AdventureWorks;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendMessage')
DROP PROCEDURE SendMessage;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendTransientResultSet')
DROP PROCEDURE SendTransientResultSet;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'ExecuteToClient')
DROP PROCEDURE ExecuteToClient;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendReaderToClient')
DROP PROCEDURE SendReaderToClient;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'ReportSqlVersion' and (type = 'FS' or type = 'FT'))
DROP FUNCTION [ReportSqlVersion];
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'InProcDA') DROP ASSEMBLY InProcDA;
GO
DECLARE @SamplesPath nvarchar(1024)
-- You may need to modify the value of the this variable if you have installed the sample someplace other than the default location.
set @SamplesPath = N'C:\MySample\'
CREATE ASSEMBLY InProcDA FROM @SamplesPath + 'InProcDA.dll'
WITH permission_set = SAFE;
GO
CREATE PROCEDURE [SendMessage] @msg nvarchar(4000)
AS
EXTERNAL NAME [InProcDA].[DataAccessDemo].[SendMessage];
GO
CREATE FUNCTION [ReportSqlVersion]() RETURNS nvarchar(4000)
AS EXTERNAL NAME [InProcDA].[DataAccessDemo].[ReportSqlVersion];
GO
CREATE PROCEDURE [SendTransientResultSet]
AS
EXTERNAL NAME [InProcDA].[DataAccessDemo].[SendTransientResultSet];
GO
CREATE PROCEDURE [ExecuteToClient]
AS
EXTERNAL NAME [InProcDA].[DataAccessDemo].[ExecuteToClient];
GO
CREATE PROCEDURE [SendReaderToClient]
AS
EXTERNAL NAME [InProcDA].[DataAccessDemo].[SendReaderToClient];
GO
以下 Transact-SQL （test.sql） 通过执行此示例中定义的存储过程和函数来测试该示例。
USE AdventureWorks;
GO
-- send a message to the client
EXEC SendMessage N'This is a test message.';
-- exec a function that does data access
SELECT dbo.ReportSqlVersion();
-- exec the proc that sends a result set to the client
EXEC SendTransientResultSet;
EXEC ExecuteToClient;
EXEC SendReaderToClient;
USE master;
GO
以下 Transact-SQL 从数据库中删除程序集、函数和存储过程。
USE AdventureWorks
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendMessage')
DROP PROCEDURE SendMessage;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendTransientResultSet')
DROP PROCEDURE SendTransientResultSet;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'ExecuteToClient')
DROP PROCEDURE ExecuteToClient;
GO
IF EXISTS (SELECT * FROM sys.procedures WHERE name = N'SendReaderToClient')
DROP PROCEDURE SendReaderToClient;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'ReportSqlVersion' and (type = 'FS' or type = 'FT'))
DROP FUNCTION [ReportSqlVersion];
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'InProcDA') DROP ASSEMBLY InProcDA;
GO