I'm trying to retrieve multiple columns from a datatable, but only from a single row -- and then set properties based on those results. I've figured out how to run multiple queries to obtain single columns at a time, but there must be a way to combine it all into one query.
Here's what I thought might work:
Dim colSettingsQry = From r In Me.GridProcColumnSettings.AsEnumerable _
Where r("DataFieldNm") = colNm _
Select New With _
{ _
.uniqueNm = r.Field(Of String)("UniqueNm").Single(), _
.sortExpression = r.Field(Of String)("SortExpression").Single(), _
.headerTxt = r.Field(Of String)("HeaderTxt").Single(), _
.headerStyleWidth = r.Field(Of String)("HeaderStyleWidth").Single(), _
.dataFormatString = r.Field(Of String)("DataFormatTxt").Single() _
}
gridCol.SortExpression = From c In colSettingsQry _
Select c.sortExpression
gridCol.HeaderText = From c In colSettingsQry _
Select c.headerTxt
... etc.
I'm guessing there's something pretty obvious that I'm missing - anyone have suggestions?
Thanks in advance.
I think you're looking for this:
Dim colSettingsQry = ... (your query)
Dim setting = colSettingsQry.FirstOrDefault()
If setting IsNot Nothing Then
gridCol.SortExpression = setting.SortExpression
gridCol.HeaderText = setting.HeaderText
...
EndIf
By FirstOrDefault you take the first element of a sequence if there is any, else Nothing.
Related
I need help in combining below SQL to code
Dim queryPersons = Query.From("ADSAccountInADSGroup") _
.Where(Function(t) t.Column("UID_ADSAccount") = uidAdsAccount) _
.SelectAll()
I'm successfull only until UID_ADsAccount = '4f58406f-8823-4530-b763-d344fc9093ed')
I need to append below piece of code as well to Dim queryPersons
and uid_adsgroup not in(select uid_adsgroup from adsgroup where cn like 'Domain%'))
and (XMarkedForDeletion <> 2) and (XOrigin = 1)))
I have a linq query that is used to display the list of requests from multiple users.And a Requestor can have multple requests(So the grid can have same Requestor multiple times). Now i am creating a dropdown list with unique Requestor that are displayed on the grid.(issue is i am not getting the distinct list but getting all the Requestor multiple times). Below is the linq query i am unsing.Can anyone suggest with correct linq query.
Dim rqstQry = From x In db.Request_vws _
Order By x.RequestID Descending _
Select x.RequestID,
Descr = x.Descr, _
RequestorName = String.Format("{0} {1}", x.FIRST_NAME, x.LAST_NAME), _
RelatedTask = GetTaskDescr(x.WorkID, x.TaskLabel, x.TaskDescr), _
RequestDescr = GetRequestDescr(x.RequestType), x.SubmitDttm, x.UpdatedDttm, _
x.ChangeDttm, _
x.MigrTimeStr, x.MigrApptTime, _
x.Requestor Ditinct
DataBind:
RequestorCB1.DataSource = rqstQry
RequestorCB1.DataTextField = "Requestor" RequestorCB1.DataValueField = "REquestor"
RequestorCB1.DataBind()
Need distinct user in the dropdownlist
Put parentheses around the LINQ query and append .Distinct()
Dim rqstQry = (From x In db.Request_vws _
Order By x.user
Select x.user).Distinct()
If you are including Request stuff in the result, then you cannot get distinct users (as Gert Arnold points out in his comment). Only include columns related to users.
If you still need information on requests then you must limit this information to one record per user. You would use a group by and use an aggregate in order to select a request (the first one, the last one etc.).
Got this by using the below query.
Dim rqstQry = (From x In db.Request_vws _
Order By x.RequestID Descending _
Select x.RequestID,
Descr = x.Descr, _
RequestorName = String.Format("{0} {1}", x.FIRST_NAME, x.LAST_NAME), _
RelatedTask = GetTaskDescr(x.WorkID, x.TaskLabel, x.TaskDescr), _
RequestDescr = GetRequestDescr(x.RequestType), x.SubmitDttm, x.UpdatedDttm, _
x.ChangeDttm, _
x.MigrTimeStr, x.MigrApptTime, _
x.Requestor). Distinct()
Dim rqstQry2 = (From y In rqstQry _
Select y.Requestor, y.RequestorName).Distinct()
I am interested in filtering some data on several different criteria. When I pull my list from the database, I currently have two .Where clauses, one .GroupBy, and one .Take. My issue is I want to take 3 from each group and add it to my list, which ultimately shouldn't be a grouped list.
Here is some code I've been working with:
Dim dateRangeEnd As New Date(Property.Year, 10, 31)
Dim configurableCount = 3
Dim unfilteredList = _repository.GetIEnumerableFromDB(param1, param2) _
.Where(Function(r) ({status1, status2, status3}) _
.Any(Function(x) r.status.HasValue AndAlso x = r.status.Value)) _
.Where(Function(r) r.StartDate.Value.Year = Property.Year AndAlso r.StartDate.Value < dateRangeEnd) _
.GroupBy(Function(r) r.StartDate.Value.Month) _
.Take(configurableCount)
How can I edit this so that I adding only the configurableCount from each month to my list?
You flatten a sequence of sequences with SelectMany.
.Where(Function(r) ({status1, status2, status3}) _
.Any(Function(x) r.status.HasValue AndAlso x = r.status.Value)) _
.Where(Function(r) r.StartDate.Value.Year = Property.Year AndAlso r.StartDate.Value < dateRangeEnd) _
.GroupBy(Function(r) r.StartDate.Value.Month) _
.SelectMany(Function(g) g.Take(configurableCount))
I am trying to insert/update my table using the values in the grid
Given below is the code I'm using to get the productId in the grid:
Dim prodId = From row As DataRow _
In grdSale.Rows _
Where row.Item(0).ToString <> "" _
Select row.Item(0)
I am getting productid correctly. Given below is the code to get the value in QTY column with respect to the productId:
For Each id As Long In prodId
Dim intpdt As Long
intpdt = id
intQty = (From row As DataRow In grdSale.Rows Where _
row.Item(0).Equals(intpdt) _
Select row.Item("QTY")).FirstOrDefault()
Next
In intQty I am getting 0 but it should be 10 or 12 as you can see in the QTY column in the grid (Enumeration yielded no results).
Where am wrong?
Try doing this and see if you get the result you expected:
intQty = _
( _
From row As DataRow In grdSale.Rows Where _
CLng(row.Item(0)) = intpdt _
Select CInt(row.Item("QTY")) _
).FirstOrDefault()
Not sure what causes your issue, but you should use the Field extension method since it is strongly typed and supports nullable types. I also don't understand why you need the additional loop and query to find the quantity of each product. This should do both:
Dim prodQTYs = From row In grdSale.Rows.Cast(Of DataRow)()
Let ProductID = row.Field(Of String)("ProductId")
Let Quantity = row.Field(Of Long)("QTY")
Where Not String.IsNullOrWhiteSpace(ProductID)
Select New With {.ProductID = ProductID, .Quantity = Quantity}
Change the types to the appropriate ones.
Output:
For Each prodInfo In prodQTYs
Console.WriteLine("Product:{0} Quantity:{1}", prodInfo.ProductID, prodInfo.Quantity)
Next
I'm querying two databases and trying to join the result sets and query out of them using LINQ. It seems it would be an easy task, but without doing an explicit join I'm having major performance issues. When I do the explicit join, I am having trouble with VB syntax for making things explicit types. Working Code, Cleaned:
For Each CurrRow In ResultsA.Tables(15).Rows
CurrDate = CurrRow("Date")
CurrID = CurrRow("ID")
CurrVal = CurrRow("Val")
Dim ResultsB = From SMW In DataSetA.Tables(0).AsEnumerable() _
Where SMW("ID") = CurrScheduleID And SMW("Time") = CurrProfileDate _
Select UTC_TS = SMW("Time"), Value = (SMW("VALUE") / 1000), Time_Zone = SMW("Time_Zone"), ID = SMW("ID")
Dim CurrentResult As Object
Dim boolSchedDateFound As Boolean = False
For Each CurrentResult In ResultsB
If CurrentResult.Value <> CurrVal Then
'LogIntegrityCheckErrorRow()
End If
boolSchedDateFound = True
Next
Next
This takes FOREVER to run with 100,000 rows.
I've been trying to rewrite this as:
Dim MismatchRows = From TableAData In DataSetA.Tables(0).AsEnumerable() Join TableBData In DataSetB.Tables(15).AsEnumerable() _
On New With {.TableAID = Convert.ToInt32(TableAData("ID")), .TableATime = Convert.ToDateTime(TableAData("Date"))} _
Equals New With {.TableBDID = Convert.ToInt32(TableBData("ID")), .TableBTime = Convert.ToDateTime(TableBData("Time"))} _
Select .................. (Hard to clean up, but this isn't the part that's failing)
And I'm having a bear of a time with it. The fundamental problem is the lack of strong typing. I've looked, but there seems to be little advice because most people doing this build EF on the data. Which isn't a terrible idea, but would require a bunch of re-engineering. So. Problem in front of me, how do I remove the error:
'Equals' cannot compare a value of type '<anonymous type> (line 2641)' with a value of type '<anonymous type> (line 2642)'.
Thank you so much for your help.
Have you tried this?
Dim MismatchRows = From TableAData In ei _
Join TableBData In e2 On _
TableAData("ID") Equals TableBData("ID") And TableAData("Data") Equals TableBData("Time")
Select .......
db.tb_DeviceGeFenceDetail.Join(db.tb_InventoryLog, Function(gfd) gfd.DeviceID, Function(il) il.deviceId, Function(gfd, il) New From { _
gfd.GeFenceLat1, _
gfd.GeFenceLng1, _
gfd.GeFenceLat2, _
gfd.GeFenceLng2, _
il.deviceName, _
il.DeviceIcon, _
gfd.DeviceID, _
il.id _
}).ToList().Where(Function(y) intValues.Contains(y.id))
you can try joining tables something like this.