我有这个linq查询:
var sku = (from a in con.MagentoStockBalances
join b in con.MFGParts on a.SKU equals b.mfgPartKey
join c in con.DCInventory_Currents on b.mfgPartKey equals c.mfgPartKey
where a.SKU != 0 && c.dcKey ==6
select new
{
Part_Number = b.mfgPartNumber,
Stock = a.stockBalance,
Recomended = a.RecomendedStock,
Cato = c.totalOnHandQuantity
}).ToList();
现在我需要删除c.dcKey == 6条件,并且具有以下内容:
var sku = (from a in con.MagentoStockBalances
join b in con.MFGParts on a.SKU equals b.mfgPartKey
join c in con.DCInventory_Currents on b.mfgPartKey equals c.mfgPartKey
where a.SKU != 0
select new
{
Part_Number = b.mfgPartNumber,
Stock = a.stockBalance,
Recomended = a.RecomendedStock,
Cato = c.totalOnHandQuantity where c.dcKey == 6,
Kerry = c.totalOnHandQuantity where c.dcKey == 7
}).ToList();
答案 0 :(得分:6)
这样的事情:
Cato = c.dcKey == 6 ? c.totalOnHandQuantity : 0,
Kerry = c.dcKey == 7 ? c.totalOnHandQuantity : 0
?:语法称为条件运算符。
答案 1 :(得分:0)
我会在join
中使用单独的查询,而不是添加其他let
:
from a in con.MagentoStockBalances
join b in con.MFGParts on a.SKU equals b.mfgPartKey
where a.SKU != 0
let cs = con.DCInventory_Currents.Where(c => b.mfgPartKey == c.mfgPartKey)
select new
{
Part_Number = b.mfgPartNumber,
Stock = a.stockBalance,
Recomended = a.RecomendedStock,
Cato = cs.Single(c => c.dcKey == 6).totalOnHandQuantity
Kerry = cs.Single(c => c.dcKey == 7).totalOnHandQuantity
}
虽然我不知道LINQ to SQL如何处理这样的查询(如果它完全处理它)。
答案 2 :(得分:-1)
var query= from x in context.a
where String.IsNullOrEmpty(param1) || (x.p == param1 && x.i == param2)
select x;