如何在SQL中获取一串行？

Question

这是我的表

MY_TABLE

| id | first4 | last4 | reason |
--------------------------------
|  1 |   123  |  456  | Cancel |
|  2 |   123  |  789  | Correct|

问题

它进入循环并获取信息,但最后它只显示最后一行

例:

id = 1 
first4 = 123 
last4 = 456 
reason = cancel

我试图实现的是一个像这样渲染的字符串:

id = 1,2;
first4 = 123,123;
last4 = 456,789;
reason = Cancel,Correct

在C#我使用

try
{
    SqlDataReader render = cmd.ExecuteReader();
    while (render.Read())
    {
        while (render.Read())
        {
            column = new Dictionary<string, string>();

            column["id"] = string.Join(",", render["id"]);
            column["first4"] = string.Join(",", render["first4"]);
            column["last4"] = string.Join(",", render["last4"]);
            column["reason"] = string.Join(",", render["reason"]);

            rows.Add(column);
        }
        render.close();
    }
}
catch (Excecption ex)
{
    console.writeline(ex);
}
finally
{
    conn.Close();
}

打电话给桌子

foreach (Dictionary<string, string> column in rows)
{
    interchange.DownloadBlacklist.id = column["id"] ;
    interchange.DownloadBlacklist.first4 = column["first4"];
    interchange.DownloadBlacklist.last4 = column["last4"];
    interchange.DownloadBlacklist.status =  column["status"];
}

实现它的最简单方法是什么？因为我设法提取信息,但我只得到表的最后一行,但不是我试图实现它的方式.

Answer 1

这可能对你有所帮助

SqlDataReader render = cmd.ExecuteReader();
List<string> IdList = new List<string>();
List<string> First4List = new List<string>();
List<string> Last4List = new List<string>();
List<string> ReasonList = new List<string>();
while (render.Read())
{
    IdList.Add(render["id"].ToString());
    First4List.Add(render["first4"].ToString());
    Last4List.Add(render["last4"].ToString());
    ReasonList.Add(render["reason"].ToString());
}
render.close();
string idstr = string.Join(",", IdList);
string first4str = string.Join(",", First4List);
string last4str = string.Join(",", Last4List);
string reasonstr = string.Join(",", ReasonList);

尝试使用UsingSQL连接和命令.这将帮助您摆脱final阻塞并使您的连接和命令关闭.

一瞥代码.

创建了字符串列表,即List<string>对于所有四列,将添加从sql读取的所有数据.

然后在一个循环中正常读取数据并分别添加列表中的所有数据.

一旦在列表中读取并填充了数据,就可以,使用Join 加入它们.