D. 使用 OUTPUT 参数 OUTPUT 参数允许外部过程、批处理或多条 Transact-SQL 语句访问在过程执行期间设置的某个值。下面的示例创建一个存储过程 (titles_sum),并使用一个可选的输入参数和一个输出参数。首先,创建过程:USE pubs GO IF EXISTS(SELECT name FROM sysobjects WHERE name = 'titles_sum' AND type = 'P') DROP PROCEDURE titles_sum GO USE pubs GO CREATE PROCEDURE titles_sum @@TITLE varchar(40) = '%', @@SUM money OUTPUT AS SELECT 'Title Name' = title FROM titles WHERE title LIKE @@TITLE SELECT @@SUM = SUM(price) FROM titles WHERE title LIKE @@TITLE GO接下来,将该 OUTPUT 参数用于控制流语言。 说明 OUTPUT 变量必须在创建表和使用该变量时都进行定义。 参数名和变量名不一定要匹配,不过数据类型和参数位置必须匹配(除非使用 @@SUM = variable 形式)。 DECLARE @@TOTALCOST money EXECUTE titles_sum 'The%', @@TOTALCOST OUTPUT IF @@TOTALCOST < 200 BEGIN PRINT ' ' PRINT 'All of these titles can be purchased for less than $200.' END ELSE SELECT 'The total cost of these titles is $' + RTRIM(CAST(@@TOTALCOST AS varchar(20)))下面是结果集:Title Name ------------------------------------------------------------------------ The Busy Executive's Database Guide The Gourmet Microwave The Psychology of Computer Cooking(3 row(s) affected)Warning, null value eliminated from aggregate.
All of these titles can be purchased for less than $200.
sqlHelper.RunProc("pr_SearchRangeSoftByName", param, out dr); recordCount =(int) param.GetValue(3);问题出在这,我返回的是一个xmlreader,参数要等xmlreader.read()之后才能产生值; 已解决! 结帖
SqlCommand sampleCMD = new SqlCommand("SampleProc", nwindConn);
sampleCMD.CommandType = CommandType.StoredProcedure;SqlParameter sampParm = sampleCMD.Parameters.Add("RETURN_VALUE", SqlDbType.Int);
sampParm.Direction = ParameterDirection.ReturnValue;sampParm = sampleCMD.Parameters.Add("@InputParm", SqlDbType.NVarChar, 12);
sampParm.Value = "Sample Value";sampParm = sampleCMD.Parameters.Add("@OutputParm", SqlDbType.NVarChar, 28);
sampParm.Direction = ParameterDirection.Output;nwindConn.Open();SqlDataReader sampReader = sampleCMD.ExecuteReader();Console.WriteLine("{0}, {1}", sampReader.GetName(0), sampReader.GetName(1));while (sampReader.Read())
{
Console.WriteLine("{0}, {1}", sampReader.GetInt32(0), sampReader.GetString(1));
}sampReader.Close();
nwindConn.Close();Console.WriteLine(" @OutputParm: {0}", sampleCMD.Parameters["@OutputParm"].Value);
Console.WriteLine("RETURN_VALUE: {0}", sampleCMD.Parameters["RETURN_VALUE"].Value);
OUTPUT 参数允许外部过程、批处理或多条 Transact-SQL 语句访问在过程执行期间设置的某个值。下面的示例创建一个存储过程 (titles_sum),并使用一个可选的输入参数和一个输出参数。首先,创建过程:USE pubs
GO
IF EXISTS(SELECT name FROM sysobjects
WHERE name = 'titles_sum' AND type = 'P')
DROP PROCEDURE titles_sum
GO
USE pubs
GO
CREATE PROCEDURE titles_sum @@TITLE varchar(40) = '%', @@SUM money OUTPUT
AS
SELECT 'Title Name' = title
FROM titles
WHERE title LIKE @@TITLE
SELECT @@SUM = SUM(price)
FROM titles
WHERE title LIKE @@TITLE
GO接下来,将该 OUTPUT 参数用于控制流语言。 说明 OUTPUT 变量必须在创建表和使用该变量时都进行定义。
参数名和变量名不一定要匹配,不过数据类型和参数位置必须匹配(除非使用 @@SUM = variable 形式)。 DECLARE @@TOTALCOST money
EXECUTE titles_sum 'The%', @@TOTALCOST OUTPUT
IF @@TOTALCOST < 200
BEGIN
PRINT ' '
PRINT 'All of these titles can be purchased for less than $200.'
END
ELSE
SELECT 'The total cost of these titles is $'
+ RTRIM(CAST(@@TOTALCOST AS varchar(20)))下面是结果集:Title Name
------------------------------------------------------------------------
The Busy Executive's Database Guide
The Gourmet Microwave
The Psychology of Computer Cooking(3 row(s) affected)Warning, null value eliminated from aggregate.
All of these titles can be purchased for less than $200.
recordCount =(int) param.GetValue(3);问题出在这,我返回的是一个xmlreader,参数要等xmlreader.read()之后才能产生值;
已解决! 结帖