將具有多個左外部聯接和各種子句的SQL語句轉換為LINQ

Question

我一直在嘗試創建關聯和導航屬性，以簡化LINQ查詢。 但是，由於我使用的是復雜的專有數據庫，這真的很難。

對於此過程的大部分時間，我一直在EF5上使用數據庫優先方法。 我無法先使用數據庫創建關聯和導航屬性，因此我嘗試在SQL Server上創建外鍵，但未成功。

在下一步中，我嘗試使用代碼優先方法創建表，關聯和導航屬性。 但是，再次由於要使用的數據庫和服務器的原因，我無法簡化查詢。

我的最后一招就是做我最初在這個問題上想要做的事情。 那就是得到這個LINQ查詢：

from item in db2.OrderFormDump
join icp in db2.IcPricP on item.NODASHITEMNO equals icp.ITEMNO into icpGroup
from iG in icpGroup.DefaultIfEmpty()
join itemInfo in db2.WebItemInfo on item.ITEMNO equals itemInfo.ITEMNO into itemInfoGroup
from iIG in itemInfoGroup.DefaultIfEmpty()
join weboeordh in db2.WebOEOrdH on "brian" equals weboeordh.USER into weboeordhGroup
from wOEODHG in weboeordhGroup.DefaultIfEmpty()
join weboeordd in db2.WebOEOrdD on new { itemno = item.NODASHITEMNO, orduniq = wOEODHG.ORDUNIQ } equals new { itemno = weboeordd.ITEMNO, orduniq = weboeordd.ORDUNIQ } into weboeorddGroup
from wOEODG in weboeorddGroup.DefaultIfEmpty()
join weboeordsubmit in db2.WebOEOrdSubmit on wOEODG.ORDUNIQ equals weboeordsubmit.ORDUNIQ into weboeordsubmitGroup
from wOEOSG in weboeordsubmitGroup.DefaultIfEmpty()
join webloginaccess in db2.WebLoginAccess on "brian" equals webloginaccess.USER into webloginaccessGroup
from wLAG in webloginaccessGroup.DefaultIfEmpty()
join arcus in db2.Arcus on wLAG.CUSTID equals arcus.IDCUST into arcusGroup
from aG in arcusGroup
where (item.ALLOWINBC == "Yes" && item.ALLOWINAB == "Yes")
&& (item.BASEDESCRIPTION.Contains("dude") || item.DESCRIPTION.Contains("dude") || item.CATEGORY.Contains("dude") || item.FOODACCSPEC.Contains("dude") || item.ITEMBRAND.Contains("dude") || item.ITEMGROUP.Contains("dude") || item.ITEMNO.Contains("dude") || item.ITEMSUBTYPE.Contains("dude") || item.ITEMTYPE.Contains("dude") || iIG.INFO.Contains("dude") || item.UPC.Contains("dude") || item.UPC.Substring(2, 10).Contains("dude"))
&& (iG.CURRENCY == "CDN" && iG.DPRICETYPE == 1)
&& wOEODG.ORDUNIQ != wOEODHG.ORDUNIQ
&& iG.PRICELIST == aG.PRICLIST
orderby item.BASEDESCRIPTION
select new { item.ITEMNO, item.BASEDESCRIPTION, iIG.INFO, item.UPC, iG.UNITPRICE, item.CASEQTY, wOEODG.QTY } into x
group x by new { x.ITEMNO, x.BASEDESCRIPTION, x.INFO, x.UPC, x.UNITPRICE, x.CASEQTY, x.QTY } into items
select items;

要獲得與此SQL查詢相同的結果：

DECLARE @search varchar(50) = 'dude'

SELECT orderformdump.itemno,basedescription,info,upc,CAST(UNITPRICE AS DECIMAL(18,2)),caseqty, sum(qty) AS userquantity
FROM PPPLTD.[dbo].[ORDERFORMDUMP] 
LEFT JOIN PPPLTD.dbo.ICPRICP ON replace(PPPLTD.[dbo].[ORDERFORMDUMP].[ITEMNO],'-','') = ICPRICP.ITEMNO
LEFT JOIN PPPLTD.dbo.WEBITEMINFO ON ORDERFORMDUMP.ITEMNO = WEBITEMINFO.ITEMNO
LEFT JOIN pppltd.dbo.weboeordh ON [user] = 'brian'
LEFT JOIN pppltd.dbo.weboeordd ON pppltd.dbo.WEBOEORDD.ITEMNO = REPLACE(pppltd.dbo.ORDERFORMDUMP.ITEMNO,'-','') and weboeordd.ORDUNIQ = weboeordh.orduniq
Left JOIN pppltd.dbo.weboeordsubmit ON weboeordsubmit.orduniq = weboeordd.ORDUNIQ and weboeordd.ORDUNIQ != weboeordsubmit.orduniq
LEFT JOIN PPPLTD.dbo.WEBLOGINACCESS ON WEBLOGINACCESS.[USER] = 'brian'
LEFT JOIN PPPLTD.dbo.ARCUS ON ARCUS.IDCUST = WEBLOGINACCESS.CUSTID
where (allowinbc = 'Yes' or allowinab = 'Yes') 
AND [PRICELIST] = ARCUS.PRICLIST 
and [CURRENCY] = 'CDN' and DPRICETYPE = 1
and (itemgroup like '%' + @search + '%' or itemtype like '%' + @search + '%' or itembrand like '%' + @search + '%' 
or subcat  like '%' + @search + '%' or orderformdump.description  like '%' + @search + '%' or basedescription like '%'+ @search + '%' 
or orderformdump.ITEMNO like '%'+@search+'%' or UPC like '%'+@search+'%' or (select top 1 1 from pppltd.dbo.ICITEMO where OPTFIELD like 'UPC%' and VALUE like '%'+@search+'%' 
and ITEMNO = pppltd.dbo.ORDERFORMDUMP.itemno) is not null) 
group by ORDERFORMDUMP.ITEMNO,BASEDESCRIPTION,info,UPC,CAST(UNITPRICE AS DECIMAL(18,2)),caseqty
order by basedescription

當我在LINQPad上執行LINQ時，它會產生以下SQL：

DECLARE @p0 NVarChar(1000) = '-'
DECLARE @p1 NVarChar(1000) = ''
DECLARE @p2 VarChar(1000) = 'brian'
DECLARE @p3 NVarChar(1000) = '-'
DECLARE @p4 NVarChar(1000) = ''
DECLARE @p5 VarChar(1000) = 'brian'
DECLARE @p6 VarChar(1000) = 'Yes'
DECLARE @p7 VarChar(1000) = 'Yes'
DECLARE @p8 VarChar(1000) = '%dude%'
DECLARE @p9 VarChar(1000) = '%dude%'
DECLARE @p10 VarChar(1000) = '%dude%'
DECLARE @p11 VarChar(1000) = '%dude%'
DECLARE @p12 VarChar(1000) = '%dude%'
DECLARE @p13 VarChar(1000) = '%dude%'
DECLARE @p14 VarChar(1000) = '%dude%'
DECLARE @p15 VarChar(1000) = '%dude%'
DECLARE @p16 VarChar(1000) = '%dude%'
DECLARE @p17 VarChar(1000) = '%dude%'
DECLARE @p18 VarChar(1000) = '%dude%'
DECLARE @p19 Int = 2
DECLARE @p20 Int = 10
DECLARE @p21 VarChar(1000) = '%dude%'
DECLARE @p22 VarChar(1000) = 'CDN'
DECLARE @p23 Int = 1
-- EndRegion
SELECT [t10].[ITEMNO], [t10].[BASEDESCRIPTION], [t10].[value] AS [INFO], [t10].[UPC], [t10].[value2] AS [UNITPRICE], [t10].[CASEQTY], [t10].[value3] AS [QTY]
FROM (
    SELECT [t9].[ITEMNO], [t9].[BASEDESCRIPTION], [t9].[value], [t9].[UPC], [t9].[value2], [t9].[CASEQTY], [t9].[value3]
    FROM (
        SELECT [t0].[ITEMNO], [t0].[BASEDESCRIPTION], [t2].[INFO] AS [value], [t0].[UPC], [t1].[UNITPRICE] AS [value2], [t0].[CASEQTY], [t5].[QTY] AS [value3], [t0].[ALLOWINBC], [t0].[ALLOWINAB], [t0].[DESCRIPTION], [t0].[CATEGORY], [t0].[FOODACCSPEC], [t0].[ITEMBRAND], [t0].[ITEMGROUP], [t0].[ITEMSUBTYPE], [t0].[ITEMTYPE], [t1].[CURRENCY], [t1].[DPRICETYPE], [t5].[ORDUNIQ], [t4].[ORDUNIQ] AS [ORDUNIQ2], [t1].[PRICELIST], [t8].[PRICLIST]
        FROM [ORDERFORMDUMP] AS [t0]
        LEFT OUTER JOIN [ICPRICP] AS [t1] ON REPLACE([t0].[ITEMNO], @p0, @p1) = [t1].[ITEMNO]
        LEFT OUTER JOIN [WEBITEMINFO] AS [t2] ON [t0].[ITEMNO] = [t2].[ITEMNO]
        LEFT OUTER JOIN (
            SELECT [t3].[ORDUNIQ]
            FROM [WEBOEORDH] AS [t3]
            WHERE @p2 = [t3].[USER]
            ) AS [t4] ON 1=1 
        LEFT OUTER JOIN [WEBOEORDD] AS [t5] ON (REPLACE([t0].[ITEMNO], @p3, @p4) = [t5].[ITEMNO]) AND ([t4].[ORDUNIQ] = [t5].[ORDUNIQ])
        LEFT OUTER JOIN (
            SELECT [t6].[CUSTID]
            FROM [WEBLOGINACCESS] AS [t6]
            WHERE @p5 = [t6].[USER]
            ) AS [t7] ON 1=1 
        LEFT OUTER JOIN [ARCUS] AS [t8] ON [t7].[CUSTID] = [t8].[IDCUST]
        ) AS [t9]
    WHERE ([t9].[ALLOWINBC] = @p6) AND ([t9].[ALLOWINAB] = @p7) AND (([t9].[BASEDESCRIPTION] LIKE @p8) OR ([t9].[DESCRIPTION] LIKE @p9) OR ([t9].[CATEGORY] LIKE @p10) OR ([t9].[FOODACCSPEC] LIKE @p11) OR ([t9].[ITEMBRAND] LIKE @p12) OR ([t9].[ITEMGROUP] LIKE @p13) OR ([t9].[ITEMNO] LIKE @p14) OR ([t9].[ITEMSUBTYPE] LIKE @p15) OR ([t9].[ITEMTYPE] LIKE @p16) OR ([t9].[value] LIKE @p17) OR ([t9].[UPC] LIKE @p18) OR (SUBSTRING([t9].[UPC], @p19 + 1, @p20) LIKE @p21)) AND ([t9].[CURRENCY] = @p22) AND ([t9].[DPRICETYPE] = @p23) AND ([t9].[ORDUNIQ] <> [t9].[ORDUNIQ2]) AND ([t9].[PRICELIST] = [t9].[PRICLIST])
    GROUP BY [t9].[ITEMNO], [t9].[BASEDESCRIPTION], [t9].[value], [t9].[UPC], [t9].[value2], [t9].[CASEQTY], [t9].[value3]
    ) AS [t10]
ORDER BY [t10].[BASEDESCRIPTION]

UPDATE

按照HBomb的回答，我決定使用參數創建存儲過程，而不是執行多個聯接：

CREATE PROCEDURE PRODUCT_PROCEDURE

    @USERID VARCHAR(MAX)
AS
BEGIN

    SELECT distinct datawarehouse.dbo.orderformdump.itemno, basedescription,info,upc,CAST((SELECT [UNITPRICE] FROM PPPLTD.dbo.[ICPRICP] WHERE [ITEMNO] = replace([DataWarehouse].[dbo].[ORDERFORMDUMP].[ITEMNO],'-','') AND [PRICELIST] = (select top 1 priclist from PPPLTD.dbo.ARCUS where IDCUST = (select top 1 CUSTID from PPPLTD.dbo.WEBLOGINACCESS where [USER] = @USERID)) and [CURRENCY] = 'CDN' and DPRICETYPE = 1) AS DECIMAL(18,2))as price,caseqty, qty AS userquantity FROM [DataWarehouse].[dbo].[ORDERFORMDUMP] LEFT JOIN pppltd.dbo.weboeordd ON pppltd.dbo.WEBOEORDD.ITEMNO = REPLACE(datawarehouse.dbo.ORDERFORMDUMP.ITEMNO,'-','') and orduniq not in (select orduniq from pppltd.dbo.weboeordsubmit) and WEBOEORDD.ORDUNIQ in (select orduniq from pppltd.dbo.weboeordh where [user] = @USERID) LEFT JOIN DATAWAREHOUSE.dbo.webiteminfo on webiteminfo.itemno = orderformdump.itemno where (allowinbc = 'Yes' or allowinab = 'Yes') order by BASEDESCRIPTION

END

然后，我使用Entity Framework的Database First方法添加了我的存儲過程，並使用在我的存儲過程中設置“ USERID”參數的方法創建了一個新的DbContext：

public partial class DataWarehouseEntities : DbContext
    {
        public DataWarehouseEntities()
            : base("name=DataWarehouseEntities")
        {
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }

        public virtual ObjectResult<PRODUCT_PROCEDURE_Result> PRODUCT_PROCEDURE(string USERID)
        {
            var USERIDParameter = USERID != null ?
                new ObjectParameter("USERID", USERID) :
                new ObjectParameter("USERID", typeof(string));

            return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<PRODUCT_PROCEDURE_Result>("PRODUCT_PROCEDURE", USERIDParameter);
        }
    }

我也嘗試過：

var USERIDParameter = USERID != null ? new SqlParameter("USERID", USERID) : new SqlParameter("USERID", typeof(string));

return ((IObjectContextAdapter)this).ObjectContext.ExecuteStoreQuery<PRODUCT_PROCEDURE‌​_Result>("PRODUCT_PROCEDURE @USERID", USERIDParameter);

最后，我嘗試對存儲過程的結果運行簡化得多的LINQ查詢：

var products = db2.PRODUCT_PROCEDURE(username).Where
                        (item => item.basedescription.Contains(searchword) 
                         || item.info.Contains(searchword)
                         || item.itemno.Contains(searchword)
                         || item.itemno.Contains(searchword.Replace("-", ""))
                         || item.upc.Contains(searchword));

但是，現在我得到了NullReferenceException，因為查詢沒有返回任何結果。

更新＃2

執行存儲過程不會導致NullReferenceException。 問題是LINQ查詢。

我發現，當我單獨擁有var products = db2.PRODUCT_PROCEDURE(username).ToList()時，它返回結果，但是當我嘗試在其上添加where子句時，它返回null。

解

在HBomb的幫助下，我解決了這個問題。 首先，與其在LINQ中創建多個聯接，或者創建關聯和導航屬性，不如在數據庫中創建視圖或存儲過程，然后使用該結果來編寫簡單的LINQ查詢，就容易得多（示例操作方法以上）。

我發現我正在獲取NullReferenceException，因為數據庫中info屬性的某些值為null。 解決該問題所需要做的就是修改存儲過程，將info列更改為isnull(info,'') as info 。

最后，為了獲得更好的搜索結果，我更改了查詢：

var searchWords = searchword.ToLower().Split(' ');

            var products = db2.PRODUCT_PROCEDURE(username).ToList()
            .Where
                    (item => item.basedescription.ToLower().Contains(searchWords[0])
                     || item.info.ToLower().Contains(searchWords[0])
                     || item.itemno.Contains(searchword)
                     || item.itemno.Contains(searchword.Replace("-", ""))
                     || item.upc.Contains(searchword)
                     || (item.price.ToString() == searchword
                     && item.price.ToString() != null));

            if (searchWords.Length > 1)
            {
                for (int x = 0; x < searchWords.Length-1; x++)
                {
                    products = products.Where(i => i.basedescription.ToLower().Contains(searchWords[x]) || i.info.ToLower().Contains(searchWords[x]));
                }
            }

謝謝。

Answer 1

如果將Sql包裝在存儲過程中，則可以使用EF來調用該過程。 這是一種方法：

 var searchParameter = new SqlParameter("@search", mySearchValue);
    this.Database.SqlQuery<YourEntityTypeForReturnVal>("MyProcedureName, @search", searchParameter);

您可以創建一個參數化的存儲過程作為Sql的包裝器：

CREATE PROCEDURE MyProcedureName
    @search varchar(50)
AS
BEGIN
-- Copy and paste your existing Sql Query here, minus the variable declaration

END

有時候，我們可以做開發商最好的（和最困難的）事情是退后一步，問“我應該做這種方式”而不是問“我該怎么做這種方式。”

Answer 2

我是在戰斗后到達的，但是這可以成為QueryFirst的工作嗎？ 您可以將SQL原樣粘貼到查詢模板中，但仍保留在您的應用程序中（更輕松的源代碼控制，版本控制和維護）。 生成的類使它可以直接從您的應用程序代碼中使用。