無法將源類型'System Linq IQueryable <decimal>'轉換爲目標類型十進制

Question

我的linq代碼是;

decimal A = (from _a in parameterEntities.BlockOfBuildingsAndParcels 
        where _a.status == 1 && _a.isActive == "1" 
        select _a.areaOfDecar) 

_a.areaOfDecar類型是decimal但它仍需要選擇只有one價值，你需要使用FirstOrDefault只選擇工作不正常

Answer 1

您試圖分配IQueryable<decimal>到decimal一個記錄：

decimal A = (from _a in parameterEntities.BlockOfBuildingsAndParcels 
      where _a.status == 1 && _a.isActive == "1" 
      select _a.areaOfDecar).FirstOrDefault();