C#三层架构中返回list，怎么只能添加一个值啊？菜鸟求救！~没分了，大牛帮忙。。
三层架构DBUtility下SQLHelper
public static string selete2(string sql, List<SqlParameter> paras)
{
string result = "";
SqlConnection conn = new SqlConnection();
try
{
conn.ConnectionString = dataBase.connString;
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = sql;
for (int i = 0; i < paras.Count; i++)
{
cmd.Parameters.Add(paras[i]);
}
SqlDataReader dr = cmd.ExecuteReader();
if (dr.Read())
{
result = dr[0].ToString();
}
return result;
}
catch
{
result = "cuola";
return result;
}
finally
{
conn.Close();
}
}
DAL层
//获取某模块题目的编号 的list
public List<string> getQuestionIdList(string moduleName,string matchName)//比赛环节名与比赛名称
{
string sql = "select questionId from matchQuestions where module='"+moduleName+ "' and match='"+matchName+"'";
List<SqlParameter> sps = new List<SqlParameter>();
List<string> quetionId = new List<string>();
quetionId.Add(DBUtility.SQLHelper.selete2(sql, sps));//怎么只能加一个questionId啊？？？？？？这儿咋改？？？
return quetionId;
}
Bll层
//获取某比赛某模块的题目列表
public List<string> selectMatchQueDistinct(string selectName, string moduleName, string matchName)
{
return dQuestions.getMatchQuescopeOf( selectName, moduleName, matchName);
}
求救，三层架构不熟悉，最后怎么只能从数据库里返回一个值。。咋改啊？？ --------------------编程问答-------------------- 数据库是不是就一个值？ --------------------编程问答-------------------- list.Items.Add();增加项的集合
试试 --------------------编程问答-------------------- 定义个数据结构，实现ISerializal接口，要多少返回多少。
--------------------编程问答-------------------- selete2只返回一个result
while(dr.Read())
{
list.Add( dr[0].ToString());
}
--------------------编程问答-------------------- 解决了。 --------------------编程问答-------------------- --------------------编程问答-------------------- --------------------编程问答-------------------- --------------------编程问答-------------------- public static string selete2(string sql, List<SqlParameter> paras)
{
string result = "";
SqlConnection conn = new SqlConnection();
try
{
conn.ConnectionString = dataBase.connString;
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = sql;
for (int i = 0; i < paras.Count; i++)
{
cmd.Parameters.Add(paras[i]);
}
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read()) //if 只读出一个 改成while循环读取
{
result = dr[0].ToString();
}
return result;
}
catch
{
result = "cuola";
return result;
}
finally
{
conn.Close();
}
}
补充：.NET技术 , C#
