C# 是否因为SQL字符串而复制值?
我创建了自己的使用内部联接的SQL字符串。以下是我的功能:C# 是否因为SQL字符串而复制值?,c#,mysql,sql,ado.net,C#,Mysql,Sql,Ado.net,我创建了自己的使用内部联接的SQL字符串。以下是我的功能: 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 + "'";
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,当我在
stocksList ListView
上单击一个项目时,recipeList ListView
将有多个值。大约5行相同的值。缺少与stocksdb的联接。大概是这样的:
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
选择s.*,mdb.menu\u名称
来自斯托克斯
客栈加盟互惠酒店
关于s.stock\u ID=r1.stock\u ID,请同时纠正我的SQL语法问题。您能提供一些示例数据吗?