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protected void Button1_Click(object sender, EventArgs e) {
//Create a local table
DataTable table = new DataTable("temp");
DataColumn col1 = new DataColumn("col1", System.Type.GetType("System.Int32"));
DataColumn col2 = new DataColumn("col2", System.Type.GetType("System.String"));
DataColumn col3 = new DataColumn("col3", System.Type.GetType("System.DateTime"));
table.Columns.Add(col1);
table.Columns.Add(col2);
table.Columns.Add(col3);
//Populate the table
for (int i = 20; i <= 30; i++)
{
object[] vals = new object[3];
vals[0] = i;
vals[1] = (char)(i + 90);
//char c1 = (char)random.Next(65, 90);
vals[2] = System.DateTime.Now;
table.Rows.Add(vals);
}
//Create a command object that calls the stored proc
using(SqlConnection conn = new SqlConnection(@"Data Source=(localdb)\projects;Initial Catalog=Northwind;Integrated Security=True"))
{
conn.Open();
SqlCommand command = new SqlCommand("usp_AddRowsToMyTable", conn);
command.CommandType = CommandType.StoredProcedure;
//Create a parameter using the new type
SqlParameter param =command.Parameters.Add("@MyTableParam", SqlDbType.Structured);
command.Parameters.AddWithValue("@UserID", "Kathi");
//Set the value of the parameter
param.Value = table;
//Execute the query
command.ExecuteNonQuery();
conn.Close();
}
}
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值参数(Table-valued parameter)是SQL Server 2008的一个新特性，在以前的版本中，没有办法把表变量当作一个参数传递给存储过程。微软在SQL Server2008中引入了表值参数的特性，可以实现这项功能。
表值参数有两大优点：一是它不需要为初始的数据加锁，二是它不会导致语句重新编译。
表值参数的创建和使用包括以下步骤：
1) 创建表类型
2) 创建一个可将表类型作为参数来接受的存储过程或函数
3) 创建表变量并插入数据
4) 调用该存储过程和函数，并将表变量作为参数传递。
下面，我们来一步步分解这个创建和使用的过程。首先，我们用以下的DDL SQL语句来创建一个名为“TestDB”的测试数据库：
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USE [master] GO IF EXISTS (SELECT name FROM sys.databases WHERE name = N‘TestDB‘) DROP DATABASE TestDB GO Create database TestDB go |
接下来我们使用以下的DDL SQL语句来创建一个名为TestLocationTable的表：
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USE [TestDB] GO IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N‘[dbo].[TestLocationTable]‘) AND type in (N‘U‘)) DROP TABLE [dbo].[TestLocationTable] GO USE [TestDB] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[TestLocationTable]( [Id] [int] NULL, [shortname] [char](3) NULL, [name] [varchar](100) NULL ) ON [PRIMARY] GO SET ANSI_PADDING OFF GO |
然后，使用以下的DML SQL语句将数据添加到我们上面创建的表中：
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USE [TestDB] GO insert into TestLocationTable ( Id, shortname, Name) select 1, ‘NA1‘, ‘NewYork‘ insert into TestLocationTable ( Id, shortname, Name) select 2, ‘NA2‘, ‘NewYork‘ insert into TestLocationTable ( Id, shortname, Name) select 3, ‘NA3‘, ‘NewYork‘ insert into TestLocationTable ( Id, shortname, Name) select 4, ‘EU1‘, ‘London‘ insert into TestLocationTable ( Id, shortname, Name) select 5, ‘EU2‘, ‘London‘ insert into TestLocationTable ( Id, shortname, Name) select 6, ‘AS1‘, ‘Tokyo‘ insert into TestLocationTable ( Id, shortname, Name) select 7, ‘AS2‘, ‘HongKong‘ go |
下一步，我们要创建一个和TestLocationTable表具有相似表结构的表类型(TABLE TYPE)，语句如下：
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USE [TestDB] GO IF EXISTS (SELECT * FROM sys.types st JOIN sys.schemas ss ON st.schema_id = ss.schema_id WHERE st.name = N‘OfficeLocation_Tabetype‘ AND ss.name = N‘dbo‘) DROP TYPE [dbo].[OfficeLocation_Tabetype] GO USE [TestDB] GO CREATE TYPE [dbo].[OfficeLocation_Tabetype] AS TABLE( [Id] [int] NULL, [shortname] [char](3) NULL, [name] [varchar](100) NULL ) GO |
紧接着，我们要创建一个可以将表类型作为一个参数来接受的存储过程，使用的语句如下：
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USE [TestDB] GO IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N‘[dbo]. [usp_InsertProdLocation]‘) AND type in (N‘P‘, N‘PC‘)) DROP PROCEDURE [dbo].[usp_selectProdLocation] GO CREATE PROCEDURE usp_InsertProdLocation @TVP OfficeLocation_Tabetype READONLY AS SET NOCOUNT ON INSERT INTO TestLocationTable Select ID, shortname, name from @TVP where convert(varchar(10),id)+shortname+name not in (select convert(varchar(10),id)+shortname+name from TestLocationTable) GO |
这个存储过程将表变量作为导入值接收，并且只插入TestLocationTable中没有的数据。现在，我们可以尝试创建一个表变量，并执行上面创建的存储过程usp_InsertProdLocation，语句如下：
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use TestDB go DECLARE @TV AS [OfficeLocation_Tabetype] INSERT INTO @TV (Id, Shortname, Name) SELECT 12, ‘ME1‘, ‘Dubai‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 13, ‘ME2‘, ‘Tehran‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 17, ‘EA1‘, ‘Bombay‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 18, ‘EA2‘, ‘Karachi‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 3, ‘NA3‘, ‘NewYork‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 4, ‘EU1‘, ‘London‘ exec usp_InsertProdLocation @TV go |
这时候，我们可以使用以下的TSQL语句从表TestLocationTable查询所有的数据：
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use TestDB go select * from TestLocationTable go |
查询结果如下所示：
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Id, shortname, name 1, NA1, NewYork 2, NA2, NewYork 3, NA3, NewYork 4, EU1, London 5, EU2, London 6, AS1, Tokyo 7, AS2, HongKong 12, ME1, Dubai 13, ME2, Tehran 17, EA1, Bombay 18, EA2, Karachi (11 row(s) affected) |
从返回的结果，我们可以看到存储过程usp_InsertProdLocation 插入了表变量@TV中和表TestLocationTable所有不匹配的行。
我们还可以将表变量传递给一个函数。下面我们创建一个简单的函数，语句如下：
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USE [TestDB] GO IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N‘[dbo].[myfunction]‘) AND type in (N‘FN‘, N‘IF‘, N‘TF‘, N‘FS‘, N‘FT‘)) DROP FUNCTION [dbo].[myfunction] GO create function dbo.myfunction (@TV OfficeLocation_Tabetype READONLY) returns int as begin declare @i int set @i=(Select COUNT(*) from @TV) return @i end |
现在，我们通过创建一个表变量并将该变量作为一个参数传递给已创建的函数以调用该函数，语句如下：
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USE [TestDB] GO DECLARE @TV AS [OfficeLocation_Tabetype] INSERT INTO @TV (Id, Shortname, Name) SELECT 12,‘ME1‘,‘Dubai‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 13,‘ME2‘,‘Tehran‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 17,‘EA1‘,‘Bombay‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 18,‘EA2‘,‘Karachi‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 3,‘NA3‘,‘NewYork‘ INSERT INTO @TV (Id, Shortname, Name) SELECT 4,‘EU1‘,‘London‘ select dbo.myfunction(@TV) go |
执行结果如下：
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(1 row(s) affected) (1 row(s) affected) (1 row(s) affected) (1 row(s) affected) (1 row(s) affected) (1 row(s) affected) ----------- 6 |
注：上面所演示的脚本都是在SQL Server 2008 CTP6版本上进行编写并经过测试的。