我必須運行1個查詢,然後用第一個結果運行另一個查詢。我意識到我可能只是拋出數組中的第一個結果集,然後遍歷數組,但有沒有一種方法來嵌套查詢,以便我不必亂搞數組?在asp.net中嵌套的SQL查詢
這裏是我當前的代碼:
SqlConnection conn2 = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["wesdb1SQL"].ToString());
SqlCommand strSQL2;
SqlDataReader itemReader2;
using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["wesdb1SQL"].ToString()))
using (SqlCommand strSQL = conn.CreateCommand())
{
strSQL.CommandText = "SELECT item_id,item_lot,item_title,item_est_lo,item_est_hi,item_timed_start,item_reserve FROM tblItem WHERE ([email protected]_sale_id) ORDER BY item_lot";
strSQL.Parameters.Add(new SqlParameter("@item_sale_id", SqlDbType.VarChar, 10, ParameterDirection.Input, true, 0, 0, "item_sale_id", DataRowVersion.Current, itemSaleId1_Var));
try
{
conn.Open();
using (SqlDataReader itemReader = strSQL.ExecuteReader())
{
if (itemReader.Read())
{
using (conn2)
using (strSQL2 = conn2.CreateCommand())
{
strSQL2.CommandText = "SELECT TOP (1) MAX(tblBidHistory.bid_price) AS bid_price, tblMailList.mail_Email1, tblBidHistory.bid_bidder_id, tblMailList.mail_FirstName, tblMailList.mail_LastName, tblBidHistory.bid_item_id FROM tblBidHistory INNER JOIN tblBidder ON tblBidHistory.bid_bidder_id = tblBidder.bidder_number AND ([email protected]_sale_id) INNER JOIN tblMailList ON tblBidder.bidder_mail_id = tblMailList.mail_ID GROUP BY tblMailList.mail_Email1, tblBidHistory.bid_bidder_id, tblMailList.mail_FirstName, tblMailList.mail_LastName, tblBidHistory.bid_item_id,tblBidHistory.bid_type,tblBidHistory.bid_date HAVING ([email protected]_id) AND (tblBidHistory.bid_type = '2') ORDER BY bid_price DESC,bid_date DESC";
strSQL2.Parameters.Add(new SqlParameter("@item_sale_id", SqlDbType.VarChar, 10, ParameterDirection.Input, true, 0, 0, "item_sale_id", DataRowVersion.Current, itemSaleId1_Var));
strSQL2.Parameters.Add(new SqlParameter("@item_id", SqlDbType.VarChar, 10, ParameterDirection.Input, true, 0, 0, "item_id", DataRowVersion.Current, itemReader["item_id"].ToString()));
try
{
conn2.Open();
using (itemReader2 = strSQL2.ExecuteReader())
{
if (itemReader2.Read())
{
if (count % 2 == 0)
{
results_Var += "<tr><td colspan=\"2\"><font size=\"2\">" + itemReader["item_lot"].ToString() + " - <u>" + itemReader["item_title"].ToString() + "</u></font></td><td><font size=\"2\">$" + itemReader["item_est_lo"].ToString() + " - $" + itemReader["item_est_hi"].ToString() + "</font></td><td>" + itemReader2["bid_price"].ToString() + " - " + itemReader2["bid_bidder_id"].ToString() + " (" + itemReader2["mail_FirstName"].ToString() + " " + itemReader2["mail_LastName"].ToString() + ")</td><td><font size=\"2\">$" + itemReader2["bid_price"].ToString() + "</font></td></tr>";
}
else
{
results_Var += "<tr><td colspan=\"2\" bgcolor=\"#b0e0e6\"><font size=\"2\">" + itemReader["item_lot"].ToString() + " - <u>" + itemReader["item_title"].ToString() + "</u></font></td><td><font size=\"2\">$" + itemReader["item_est_lo"].ToString() + " - $" + itemReader["item_est_hi"].ToString() + "</font></td><td>" + itemReader2["bid_price"].ToString() + " - " + itemReader2["bid_bidder_id"].ToString() + " (" + itemReader2["mail_FirstName"].ToString() + " " + itemReader2["mail_LastName"].ToString() + ")</td><td><font size=\"2\">$" + itemReader2["bid_price"].ToString() + "</font></td></tr>";
}
}
itemReader2.Close();
}
}
catch (Exception e1)
{
throw new Exception(e1.Message);
}
finally
{
conn2.Close();
}
}
}
itemReader.Close();
}
}
catch (Exception e2)
{
throw new Exception(e2.Message);
}
finally
{
conn.Close();
}
}
兩個查詢的輸出用於創建多行數據的表。每行都是數據庫中的一個項目,出價者的信息最高,包括出價本身以及一些類別信息。類別信息是第一個查詢,而唯一項目信息是第二個查詢(在這裏您可以看到使用兩個結果集構建的表格行)。
編輯
我改變xQbert查詢一點,結束了:
SELECT MAX(BH.bid_price) AS bid_price, ML.mail_Email1, BH.bid_bidder_id, ML.mail_FirstName, ML.mail_LastName, BH.bid_item_id, I.item_lot, I.item_title, I.item_est_lo, I.item_est_hi, I.item_timed_start, I.item_reserve
FROM tblBidHistory BH
INNER JOIN tblBidder B ON BH.bid_bidder_id = B.bidder_number AND ([email protected]_sale_id)
INNER JOIN tblMailList ML ON B.bidder_mail_id = ML.mail_ID
INNER JOIN tblItem I ON I.Item_ID = BH.Bid_item_id
WHERE ([email protected]_sale_id) And (BH.bid_type = '2')
GROUP BY ML.mail_Email1, BH.bid_bidder_id, ML.mail_FirstName, ML.mail_LastName, BH.bid_item_id, BH.bid_type, BH.bid_date, I.item_lot, I.item_title, I.item_est_lo, I.item_est_hi, I.item_timed_start, I.item_reserve
ORDER BY I.Item_Lot
這給我的數據,但它給了我所有的投標人對每個項目,而不是爲每個出價最高項目。我不確定是否需要進行不同的分組,也可能使用子查詢。
此外,要做到這一點,我只是作出1查詢。但是,我仍然想知道如何在SQL中進行嵌套查詢。
正在使用的是何種數據庫? – 2012-01-02 16:30:47
SQL。如果你想要的東西,我不知道。抱歉。我將如何發現? – James 2012-01-02 16:37:04
看到一些樣本預期輸出真的很有用。 MS-SQL(2005/2008等),MySQL,Oracle,DB2,PostGres, – xQbert 2012-01-02 16:41:03