[英]How can add Query LINQ to get result from table?
我想顯示所有月份和所有價格的輸出,但是我想按組月份和每個月的總價顯示:查看照片的輸出方式
[HttpGet("api/recent-reports")]
public JsonResult GetStatusSummaryRecentReports()
{
try
{
IEnumerable<Booking> list = _bookingDataService
.Query(d => d.BookingDate.Month < (DateTime.Now.Month));
IEnumerable<int> data_month = list.Select(d => d.BookingDate.Month)
.Distinct().Take(4);
StatusSummaryRecentReports obj = new StatusSummaryRecentReports();
//obj.Total_Order_ByMonth = Total_PriceOreder_Each_Month;
//obj.Months = Months;
return Json(obj);
}
catch (Exception ex)
{
Response.StatusCode = (int)HttpStatusCode.BadRequest;
return Json(new { message = ex.Message });
}
}
以下代碼段可能會有所幫助:
注意:tbl51567840-這是一個表,具有與您的片段相同的數據
//Solution:1 - step by step
//Step 1.1 > Create iQueryable view to get desired fields to make it virutal/logical table!
//It is inline query and it is not executed here until you call ToList at below. So it is just like SQL CTE
var query1 = (from i in db.tbl51567840
select new { Month = i.BookingDate.Value.Month, Price = i.Price.Value });
//Step 1.2 > Apply conditions and other logic to get desired result
var result = (from l in query1
where l.Month < DateTime.Now.Month
group l by l.Month into g
select new { Month = g.Key, Total = g.Sum(s => s.Price) }).ToList();
//Solution:2 Result in one linq query
var query2 = (from i in db.tbl51567840
where i.BookingDate.Value.Month < DateTime.Now.Month
group i by i.BookingDate.Value.Month into g
select new { Month = g.Key, Total = g.Sum(s => s.Price) }).ToList();
好吧,如果您需要一些建議:
1-我建議您從控制器方法中刪除業務邏輯。 嘗試在名為SERVICES或BLL的新文件夾中創建一個新類,並從那里進行所有邏輯,然后在控制器方法中調用它。
2-使用“異步任務”模式制作方法,以便在完成某些任務之前,您不會在應用程序中看到死鎖。
3-在控制器類中使用ActionResult返回方法而不是JSonResult,以便在方法中有不同的返回值時使用它。
示例2和3:
[HttpGet("api/recent-reports")]
public async Task<ActionResult> GetStatusSummaryRecentReports()
{
// When you call your class that has your Business logic, make it as async task pattern as well, so you will call it using the await keyword such as:
// MyBusinessLogicClass resultFromBll = new MyBusinessLogicClass();
// var getResult = await resultFromBll.MethodGroupByMonthAndSum();
...your controller code here...
}
4-參考Newtonsoft.json,在NuGet上查看它,它將對JSON有很大幫助
回答您的問題,請遵循以下示例: Linq按日期獲取數據組的總和
static void Main()
{
var list = new List<meter_reading>
{
new meter_reading {Date = new DateTime(2000, 2, 15), T1 = 2, T2 = 3},
new meter_reading {Date = new DateTime(2000, 2, 10), T1 = 4, T2 = 5},
new meter_reading {Date = new DateTime(2000, 3, 15), T1 = 2, T2 = 3},
new meter_reading {Date = new DateTime(2000, 3, 15), T1 = 5, T2 = 4}
};
var sum = list
.GroupBy(x => GetFirstDayInMonth(x.Date))
.Select(item => new meter_reading
{
Date = item.Key,
T1 = item.Sum(x => x.T1),
T2 = item.Sum(x => x.T2),
}).ToList();
}
private static DateTime GetFirstDayInMonth(DateTime dateTime)
{
return new DateTime(dateTime.Date.Year, dateTime.Date.Month, 1);
}
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