ADO.NET之存储过程的调用

            string source = "server=(local) \\SQLEXPRESS;integrated security=SSPI;database=Student";
            SqlConnection con = new SqlConnection(source);//建立一个连接
            con.Open();//打开数据库
            if (con.State == ConnectionState.Open)//ConnectionState为枚举值，描述数据源的连接状态为打开
                Console.WriteLine("数据库连接成功！");

            SqlCommand com = new SqlCommand("studentupdate", con);//创建一条命令，调用命令将要执行在sql 2008中定义好的存储过程
            //接着开始调用存储过程，因为该存储过程中有两个输入参数，所以需要构建两个参数，设置他们的值，然后添加到Parameters（参数集合）中
            com.CommandType = CommandType.StoredProcedure;//com.CommandType：获取或设置一个值，该值指示如何解释 CommandText属性，CommandText属性：对数据源执行的 Transact-SQL 语句、表名或存储过程   CommandType枚举指定如何解释命令字符串
            com.Parameters.AddWithValue("@id", 1);//表示向 SqlParameterCollection 的末尾添加值,SqlParameterCollection表示参数的集合，该语句还可以用com.Parameters.Add(new SqlParameter("@id","id"))代替
            com.Parameters.AddWithValue("@name", "bob");
            int x = com.ExecuteNonQuery();//调用该存储过程
            Console.WriteLine("受影响的行数：{0}", x);

--写好的存储过程必须执行或保存，SqlCommand类才能创建成功
use Student
go
create procedure studentupdate(@id int,@name char(10))
as
set nocount off--当 SET NOCOUNT 为 ON 时，不返回计数（表示受 Transact-SQL 语句影响的行数）。当 SET NOCOUNT 为 OFF 时，返回计数。
update customers
set name=@name
where id=@id; 

            SqlCommand com2 = new SqlCommand("studentdelete", con);
            com2.CommandType = CommandType.StoredProcedure;
            SqlParameter sp = new SqlParameter("@id", SqlDbType.Int, 0, "id");
            com2.UpdatedRowSource = UpdateRowSource.None;//UpdateRowSource枚举：指定如何将查询命令结果应用到正在更新的行，none表示忽略任何返回的参数或行
            com2.Parameters.Add(sp);//将指定的 SqlParameter 对象添加到 SqlParameterCollection 中,参数还没有赋值，而com.Parameters.AddWithValue（）已经赋值
            sp.Value = 1;//或者用cmd.Parameters["@id"].value=1
            com2.ExecuteNonQuery();
            Console.WriteLine("删除成功！");
            con.Close();

use Student
drop procedure studentdelete;
go
create procedure studentdelete(@id int)
as
set nocount off
delete from Customers
where id=@id

            SqlCommand com5 = new SqlCommand("selectstudent", con);
            com5.CommandType = CommandType.StoredProcedure;
            com5.Parameters.Add("@id", 5);
            SqlDataReader data=com5.ExecuteReader();
            while (data.Read())
            {
                Console.WriteLine("name:{0} id:{1}", data[0], data[1]);
            }

use Student
drop procedure selectstudent
go
create procedure selectstudent(@id int)
as
select *
from Customers
where id<=@id

            SqlCommand com3 = new SqlCommand("studentinsert", con);
            com3.CommandType = CommandType.StoredProcedure;
            com3.Parameters.Add(new SqlParameter("@name", "李四"));
            com3.Parameters.Add(new SqlParameter("@id",SqlDbType.Int,0,ParameterDirection.Output,false,0,0,"id",DataRowVersion.Default,0));
            com3.UpdatedRowSource = UpdateRowSource.OutputParameters;//UpdateRowSource枚举：指定如何将查询命令结果应用到正在更新的行,OutputParameters表示将输出参数映射到dataset中已经更改的行
            com3.ExecuteNonQuery();
            int x = (int)com3.Parameters["@id"].Value;//获得输出参数的方式
            Console.WriteLine("输出参数(下一个id号)为：{0}", x);

use Student
drop procedure studentinsert
go
create procedure studentinsert(@name char(20),@id int output)
as
set nocount off
select @id=MAX(id)+1
from Customers
insert into Customers
values(@name,@id);

            SqlCommand com4 = new SqlCommand("returnstudent", con);
            com4.CommandType = CommandType.StoredProcedure;
            com4.Parameters.Add(new SqlParameter("@id", 3));
            com4.Parameters.Add(new SqlParameter("@rid", SqlDbType.Int, 0, ParameterDirection.Output, false, 0, 0, "id", DataRowVersion.Default, 0));
            com4.Parameters.Add("@rname", SqlDbType.Char, 20).Direction= ParameterDirection.Output;//这种方式可以省略不必要的参数
            com4.ExecuteNonQuery();
            int x = (int)com4.Parameters["@id"].Value;
            string y=com4.Parameters["@rname"].Value.ToString().Trim();
            Console.WriteLine("id:{0} name:{1}",x,y);

use Student
drop procedure returnstudent
go
create procedure returnstudent(@id int,@rid int output,@rname char(20) output)
as
select @rid=id,@rname=Name
from Customers
where id=@id;