在C＃中查询两个数据库中的数据
我目前有一个查询，我从两个不同的数据库中获取数据，这些数据被附加到一个名为“accountbuys”的列表中。
-
我的第一张表有三个数据输入（3个想买股票的账户
-
下一个表有17个数据点（17个要买的股票）
我正在合并这些表并获得输出
但是，我想要的输出应该每次为3个不同的账户重复17个数据点，以便最终用户可以向下钻取并购买他想要的任何股票
这是我的代码：`
public List<BuySellModel> GetBuyDataWthAccount()
{
List<BuySellModel> accountbuys = new List<BuySellModel>();
using (SqlConnection connectionreit = new SqlConnection(HubConnection))
using (SqlConnection connection = new SqlConnection(PMConnection))
{
connectionhub.Open();
connection.Open();
SqlCommand command3 = new SqlCommand(@"SELECT distinct(table1.name) as 'Symbol' ,table2.Segment as 'Segment',table2.AllocationAmount as 'AllocationAmount',table2.PX_LAST as 'Price',
table1.CUR_MKT_CAP as 'CMC',table1.FCFY_WITH_CUR_MKT_CAP as 'FCMC',table1.ROIC as 'ROIC', table1.ROICDELTA as 'ROICD' FROM View_REIT_Model_And_Holdings as table1
INNER JOIN [MostRecentlyInModelSelected] as table2
ON table1.name = table2.Ticker
WHERE table1.AllocationAmount != -1 AND
NOT EXISTS (SELECT NULL FROM [ViewPCData] as table3 WHERE table1.name = table3.Symbol AND table2.Segment = table3.SubsectorDescription AND table3.Objective = 'REITS' AND table3.SectorDescription != 'NULL' AND table3.SubsectorDescription != 'NULL')",
connectionreit);
command3.CommandType = CommandType.Text;
SqlCommand command4 = new SqlCommand("SELECT PortfolioAccountNumber, PortfolioDescription, SUM(TotalValue) as 'TotalValue' FROM [ViewPCData] WHERE Objective = 'REITS' GROUP BY PortfolioAccountNumber,PortfolioDescription", connection);
command4.CommandType = CommandType.Text;
var reader = command3.ExecuteReader();
var reader1 = command4.ExecuteReader();
if (reader1.HasRows)
{
while (reader1.Read())
{
BuySellModel accountb = new BuySellModel();
accountb.PortfolioAccount = reader1.GetString(reader1.GetOrdinal("PortfolioAccountNumber"));
accountb.PortfolioDescription = reader1.GetString(reader1.GetOrdinal("PortfolioDescription"));
accountb.AccountAmount = reader1.GetDecimal(reader1.GetOrdinal("TotalValue"));
accountbuys.Add(accountb);
if (reader.HasRows)
{
//foreach(var account in accountbuys)
//{
while (reader.Read())
{
BuySellModel buy = new BuySellModel();
buy.Symbol = reader.GetString(reader.GetOrdinal("Symbol"));
buy.Segment = reader.GetString(reader.GetOrdinal("Segment"));
//if (accountNumber == "soand os")
//{
// 1/3 of totalaccountvalue
buy.AllocationAmount = (reader.GetDouble(reader.GetOrdinal("AllocationAmount")));
//}
buy.Price = reader.GetDouble(reader.GetOrdinal("Price"));
buy.MarketValue = reader.GetDouble(reader.GetOrdinal("CMC"));
buy.FCFY = reader.GetDouble(reader.GetOrdinal("FCMC"));
buy.ROIC = reader.GetDouble(reader.GetOrdinal("ROIC"));
buy.ROICdelta = reader.GetDouble(reader.GetOrdinal("ROICD"));
buy.Buy = true;
//account1 = account.accountnumber;
accountbuys.Add(buy);
}
//} //for loop
}
} // accounts
} //reader1.hasrows
connectionhub.Close();
connection.Close();
}
return accountbuys;
}
编辑：
将表拆分为两个不同的列表，稍后将它们合并。这现在运作良好。似乎也适合扩展。
public List<BuySellModel> GetBuyDataWthAccount()
{
List<BuySellModel> accountbuys = new List<BuySellModel>();
List<Account> accounts = new List<Account>();
using (SqlConnection connection = new SqlConnection(PMConnection))
{
connection.Open();
SqlCommand command3 = new SqlCommand(@"SELECT distinct(table1.name) as 'Symbol' ,table2.Segment as 'Segment',table2.AllocationAmount as 'AllocationAmount',table2.PX_LAST as 'Price',
table1.CUR_MKT_CAP as 'CMC',table1.FCFY_WITH_CUR_MKT_CAP as 'FCMC',table1.ROIC as 'ROIC', table1.ROICDELTA as 'ROICD' FROM View_Model_And_Holdings as table1
INNER JOIN [MostRecentlyInModelSelected] as table2
ON table1.name = table2.Ticker
WHERE table1.AllocationAmount != -1 AND
NOT EXISTS (SELECT NULL FROM [ViewPCData] as table3 WHERE table1.name = table3.Symbol AND table2.Segment = table3.SubsectorDescription AND table3.Objective = 'STOCKS' AND table3.SectorDescription != 'NULL' AND table3.SubsectorDescription != 'NULL')",
connectionreit);
command3.CommandType = CommandType.Text;
SqlCommand command4 = new SqlCommand("SELECT PortfolioDetail , SUM(TotalValue) as 'TotalValue' FROM [ViewPCData] WHERE Objective = 'STOCKS' GROUP BY PortfolioAccountNumber,PortfolioDescription", connection);
command4.CommandType = CommandType.Text;
var reader = command3.ExecuteReader();
var reader1 = command4.ExecuteReader();
if (reader1.HasRows)
{
while (reader1.Read())
{
Account accountb = new Account();
accountb.PortfolioDetail = reader1.GetString(reader1.GetOrdinal("PortfolioDetail"));
// accountb.PortfolioDescription = reader1.GetString(reader1.GetOrdinal("PortfolioDescription"));
accountb.AccountAmount = reader1.GetDecimal(reader1.GetOrdinal("TotalValue"));
accounts.Add(accountb);
}
}
//List<BuyReits> buys = new List<BuyReits>();
if (reader.HasRows && accounts.Count > 0)
{
while (reader.Read())
{
foreach (var acc in accounts)
{
BuySellModel buy = new BuySellModel();
buy.Symbol = reader.GetString(reader.GetOrdinal("Symbol"));
buy.Segment = reader.GetString(reader.GetOrdinal("Segment"));
buy.AllocationAmount = (reader.GetDouble(reader.GetOrdinal("AllocationAmount")));
buy.Price = reader.GetDouble(reader.GetOrdinal("Price"));
//buy.Quantity = reader.GetInt32((reader.GetOrdinal("AllocationAmount"))/(reader.GetOrdinal("Price")));
buy.MarketValue = reader.GetDouble(reader.GetOrdinal("CMC"));
buy.FCFY = reader.GetDouble(reader.GetOrdinal("FCMC"));
buy.ROIC = reader.GetDouble(reader.GetOrdinal("ROIC"));
buy.ROICdelta = reader.GetDouble(reader.GetOrdinal("ROICD"));
buy.Buy = true;
buy.PortfolioAccount = acc.PortfolioDetail;
buy.AccountAmount = acc.AccountAmount;
accountbuys.Add(buy);
}
}
}
connection.Close();
}
return accountbuys;
}
2 个答案:
答案 0 :(得分：2)
以下提供了C＃层中的交叉连接（并不是说它是最好的解决方案，但它让您更接近准备好了）：
using (SqlConnection connectionhub = new SqlConnection(HubConnection))
using (SqlConnection connection = new SqlConnection(PMConnection))
{
connectionhub.Open();
connection.Open();
SqlCommand command3 = new SqlCommand(@"
SELECT distinct(table1.name) as 'Symbol',
table2.Segment as 'Segment',
table2.AllocationAmount as 'AllocationAmount',
table2.PX_LAST as 'Price',
table1.CUR_MKT_CAP as 'CMC',
table1.FCFY_WITH_CUR_MKT_CAP as 'FCMC',
table1.ROIC as 'ROIC',
table1.ROICDELTA as 'ROICD'
FROM View_REIT_Model_And_Holdings as table1
INNER JOIN [MostRecentlyInModelSelected] as table2
ON table1.name = table2.Ticker
WHERE table1.AllocationAmount != -1
AND NOT EXISTS (SELECT NULL
FROM [ViewPCData] as table3
WHERE table1.name = table3.Symbol
AND table2.Segment = table3.SubsectorDescription
AND table3.Objective = 'REITS'
AND table3.SectorDescription != 'NULL'
AND table3.SubsectorDescription != 'NULL')",
connectionreit);
command3.CommandType = CommandType.Text;
SqlCommand command4 = new SqlCommand(@"
SELECT PortfolioAccountNumber,
PortfolioDescription,
SUM(TotalValue) as 'TotalValue'
FROM [ViewPCData]
WHERE Objective = 'REITS'
GROUP BY PortfolioAccountNumber, PortfolioDescription", connection);
command4.CommandType = CommandType.Text;
var stocksDS = new DataSet();
var stocksDA = new System.Data.SqlClient.SqlDataAdapter();
stocksDA.SelectCommand = command3
stocksDA.Fill(stocksDS, "stocks");
var acctsDS = new DataSet();
var acctsDA = new System.Data.SqlClient.SqlDataAdapter();
acctsDA.SelectCommand = command4
acctsDA.Fill(acctsDS, "accts");
var stocks = stocksDS.Tables["stocks"].AsEnumerable();
var accts = acctsDS.Tables["accts"].AsEnumerable();
var results = (from stocksDR in stocks
from acctsDR in accts
select new BuySellModel {
PortfolioAccount = acctsDR["PortfolioAccountNumber"],
PortfolioDescription = acctsDR["PortfolioAccountDescription"],
AccountAmount = acctsDR["TotalValue"],
Symbol = stocksDR["Symbol"],
Segment = stocksDR["Segment"],
AllocationAmount = stocksDR["AllocationAmount"],
Price = stocksDR["Price"],
MarketValue = stocksDR["CMC"],
FCFY = stocksDR["FCMC"],
ROIC = stocksDR["ROIC"],
ROICdelta = stocksDR["ROICD"],
Buy = true
});
foreach (BySellModel buy in results) {
accountBuys.Add(buy);
}
connectionhub.Close();
connection.Close();
}
编辑：删除了违规的圆括号。
答案 1 :(得分：0)
在不更改任何C＃代码的情况下，可以通过将INNER JOIN查询中的SQL查询更改为CROSS JOIN查询来获得所需内容。
关于这种方法的一些警告：
-
如果包含WHERE子句，则查询将充当INNER JOIN。
-
交叉连接可能会明显变慢，因为查询正在寻找所有可能的组合。只有51（3 * 17）种组合可用，这不会是一个重大问题，但如果您希望将其扩展到更多客户和股票，那么性能将变得越来越差
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