Store Procedure return Varchar(max) _return varchar2(max)-优快云博客

本文介绍了一个使用C#调用SQL Server存储过程来获取指定文档摘要的例子。该方法通过设置输入参数为文档ID，并定义一个输出参数来接收摘要内容。此方案适用于需要从数据库中快速检索文档摘要的应用场景。

http://msdn.microsoft.com/zh-cn/library/bb399384(VS.90).aspx



static
 private
 string
 GetDocumentSummary(int
 documentID)

{

    //Assumes GetConnectionString returns a valid connection string.


    using
 (SqlConnection connection =

               new
 SqlConnection(GetConnectionString()))

    {

        connection.Open();

        SqlCommand command = connection.CreateCommand();

        try


        {

            // Setup the command to execute the stored procedure.


            command.CommandText = "GetDocumentSummary"
;

            command.CommandType = CommandType.StoredProcedure;



            // Set up the input parameter for the DocumentID.


            SqlParameter paramID =

                new
 SqlParameter("@DocumentID"
, SqlDbType.Int);

            paramID.Value = documentID;

            command.Parameters.Add(paramID);



            // Set up the output parameter to retrieve the summary.


            SqlParameter paramSummary =

                new
 SqlParameter("@DocumentSummary"
,

                SqlDbType.NVarChar, -1);


            paramSummary.Direction = ParameterDirection.Output;

            command.Parameters.Add(paramSummary);



            // Execute the stored procedure.


            command.ExecuteNonQuery();

            Console.WriteLine((String)(paramSummary.Value));

            return
 (String)(paramSummary.Value);

        }

        catch
 (Exception ex)

        {

            Console.WriteLine(ex.Message);

            return
 null
;

        }

    }

}