c# - 是否因为SQL字符串而导致值重复？

我制作了自己的使用INNER JOINS的SQL字符串。这是我的功能:

string cmdstr = @"SELECT s.*, mdb.menu_name
                  FROM stocksdb s, recipelist rl
                  INNER JOIN menudb mdb  ON rl.menu_ID = mdb.menu_ID
                  WHERE rl.stock_ID = '" + stockID + "'";

var cmd = new MySqlCommand(cmdstr, db.mycon);
var dr = cmd.ExecuteReader();
while (dr.Read())
{
    var menuname = dr["menu_name"].ToString();

    stockIDTxtbox.Text = stockID;
    nameTxtBox.Text = dr["stock_name"].ToString();
    availableTxtbox.Text = dr["stock_quantity"].ToString();
    pricePerPieceTxtbox.Text = dr["stock_pricePerPiece"].ToString();
    limitTxtBox.Text = dr["stock_limit"].ToString());

    recipeList.Items.Add(new ListViewItem(new[] { menuname });
}

现在的问题是，当我单击stocksList ListView上的一个项目时，recipeList ListView将具有多个值。像5个左右的相同值的行。

最佳答案

缺少与stocksdb的联接。像这样的东西:

   SELECT s.*, mdb.menu_name
   FROM stocksdb s

   INNRER JOIN recipelist rl
   ON s.stock_ID= r1.stock_ID   <== this join was missing

   INNER JOIN menudb mdb
   ON rl.menu_ID = mdb.menu_ID
   WHERE rl.stock_ID = '" + stockID

关于c# - 是否因为SQL字符串而导致值重复？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/13984084/