Hi people :) I'm having trouble with a null result, when I compare the query it said I cant it give the following error "sequence contains no elements"
Dim existe = (
From p In abc.Ventadetalles
Where p.idarticulo = txtArticulo.Text
And p.idventa = IdventaTextBox.Text
Select p).Single
here is the code
The error is correct: the sequence has no elements! You are using Single(), so empty sequences produce an error. If you'd like to instead return the default value, then use SingleOrDefault().
If you expect there to actually be elements in the sequence, then double-check your conditions and source data again.
Try using SingleOrDefault. This should work.
Alternatively you could use Any() since it looks like you are trying to test for existence.
The following will work:
Dim existe = (
From p In abc.Ventadetalles
Where p.idarticulo = txtArticulo.Text
And p.idventa = IdventaTextBox.Text
Select p).SingleOrDefault()
If existe Is Not Nothing Then
'' here you can use existe
End If
Related
I have the following select statement in ABAP:
SELECT munic~mandt VREFER BIS AB ZZELECDATE ZZCERTDATE CONSYEAR ZDIMO ZZONE_M ZZONE_T USAGE_M USAGE_T M2MC M2MT M2RET EXEMPTMCMT EXEMPRET CHARGEMCMT
INTO corresponding fields of table GT_INSTMUNIC_F
FROM ZCI00_INSTMUNIC AS MUNIC
INNER JOIN EVER AS EV on
MUNIC~POD = EV~VREFER(9).
"where EV~BSTATUS = '14' or EV~BSTATUS = '32'.
My problem with the above statement is that does not recognize the substring/offset operation on the 'ON' clause. If i remove the '(9) then
it recognizes the field, otherwise it gives error:
Field ev~refer is unknown. It is neither in one of the specified tables
nor defined by a "DATA" statement. I have also tried doing something similar in the 'Where' clause, receiving a similar error:
LOOP AT gt_instmunic.
clear wa_gt_instmunic_f.
wa_gt_instmunic_f-mandt = gt_instmunic-mandt.
wa_gt_instmunic_f-bis = gt_instmunic-bis.
wa_gt_instmunic_f-ab = gt_instmunic-ab.
wa_gt_instmunic_f-zzelecdate = gt_instmunic-zzelecdate.
wa_gt_instmunic_f-ZZCERTDATE = gt_instmunic-ZZCERTDATE.
wa_gt_instmunic_f-CONSYEAR = gt_instmunic-CONSYEAR.
wa_gt_instmunic_f-ZDIMO = gt_instmunic-ZDIMO.
wa_gt_instmunic_f-ZZONE_M = gt_instmunic-ZZONE_M.
wa_gt_instmunic_f-ZZONE_T = gt_instmunic-ZZONE_T.
wa_gt_instmunic_f-USAGE_M = gt_instmunic-USAGE_M.
wa_gt_instmunic_f-USAGE_T = gt_instmunic-USAGE_T.
temp_pod = gt_instmunic-pod.
SELECT vrefer
FROM ever
INTO wa_gt_instmunic_f-vrefer
WHERE ( vrefer(9) LIKE temp_pod ). " PROBLEM WITH SUBSTRING
"AND ( BSTATUS = '14' OR BSTATUS = '32' ).
ENDSELECT.
WRITE: / sy-dbcnt.
WRITE: / 'wa is: ', wa_gt_instmunic_f.
WRITE: / 'wa-ever is: ', wa_gt_instmunic_f-vrefer.
APPEND wa_gt_instmunic_f TO gt_instmunic_f.
WRITE: / wa_gt_instmunic_f-vrefer.
ENDLOOP.
itab_size = lines( gt_instmunic_f ).
WRITE: / 'Internal table populated with', itab_size, ' lines'.
The basic task i want to implement is to modify a specific field on one table,
pulling values from another. They have a common field ( pod = vrefer(9) ). Thanks in advance for your time.
If you are on a late enough NetWeaver version, it works on 7.51, you can use the OpenSQL function LEFT or SUBSTRING. Your query would look something like:
SELECT munic~mandt VREFER BIS AB ZZELECDATE ZZCERTDATE CONSYEAR ZDIMO ZZONE_M ZZONE_T USAGE_M USAGE_T M2MC M2MT M2RET EXEMPTMCMT EXEMPRET CHARGEMCMT
FROM ZCI00_INSTMUNIC AS MUNIC
INNER JOIN ever AS ev
ON MUNIC~POD EQ LEFT( EV~VREFER, 9 )
INTO corresponding fields of table GT_INSTMUNIC_F.
Note that the INTO clause needs to move to the end of the command as well.
field(9) is a subset operation that is processed by the ABAP environment and can not be translated into a database-level SQL statement (at least not at the moment, but I'd be surprised if it ever will be). Your best bet is either to select the datasets separately and merge them manually (if both are approximately equally large) or pre-select one and use a FAE/IN clause.
They have a common field ( pod = vrefer(9) )
This is a wrong assumption, because they both are not fields, but a field an other thing.
If you really need to do that task through SQL, I'll suggest you to check native SQL sentences like SUBSTRING and check if you can manage to use them within an EXEC_SQL or (better) the CL_SQL* classes.
I have a list of Tuples I am trying to run a Select and Where query on to return a list of Objects from the Tuple.Item5 parameter. In my where clause I am looking to match Tuple.Item4 to a local variable.
I'm not sure what the VB.NET syntax is for the Select portion, I only know the c# syntax.
Essentially I am trying to select Tuple.Item5 from my list of tuples where Tuple.Item4 = sCurID. I'm unsure as to what should go in the Select section although in c# I believe it would be Select(t => t.Item5)
This is what I have:
listObj = listTuples.Select( Unsure What Goes Here ).Where(Function(w) w.Item4 = sCurID)
Once you apply the Select in C# or VB, you have reduced the Tuple to the Item5 value and can't access Item4. Do the Select last:
Dim listObj = listTuples.Where(Function(t) t.Item4 = sCurId).Select(Function(t) t.Item5)
listObj = listTuples.Select(Function(t) t.Item5).Where(Function(w) w.Item4 = sCurID).ToList()
I'm looking for a concise one line method to get a single value from a DataTable using lambda using VB.Net
This code works
OPT_UDLY = (From X In DATA.OPTIONs
Where X.CONTRACT = CTC
Select X.UDLY).Single()
but I'd like to get the value in one line like this (which doesn't work)
OPT_UDLY = DATA.Where(function(t) t.contract.Equals(CTC)).Distinct()
Any suggestions please?
Try this:
OPT_UDLY = Data.OPTIONs.Where(Function(t) t.CONTRACT = CTC).Select(Function(x) x.UDLY).Single()
Since you use Data.OPTIONs in the multiple LINQ lines, it should be consistently used for single line too.
Also, since you only need the UDLY element, use further Select LINQ expression in single line style, like what you did in your multiple lines.
And lastly, use Single to return the matching value if there is only one match, like what you already did.
Just remove the line feeds:
OPT_UDLY = (From X In DATA.OPTIONs Where X.CONTRACT = CTC Select X.UDLY).Single()
It's shorter and more readable than the lambda equivalent:
OPT_UDLY = Data.OPTIONs.Where(Function(t) t.CONTRACT = CTC).Select(Function(x) x.UDLY).Single()
I'm a newbie at Hibernate so excuse me if some of this is glaringly obvious but it's been a very, very long day. I am trying to create and execute a simple query in Hibernate and Toad/Oracle.
The Toad/Oracle sql reads:
select
count(*)
from
fpps_owner.fee_claim_payment_lines l,
fpps_owner.fee_claim_payments p
where
l.fee_claim_payment_id = p.fee_claim_payment_id and
p.claim_index = 87167895
The above returns 10 records, which is correct
The following Java code returns 0 records, which is NOT correct
String sLinesAvailable =
"select count(*) from " +
"fpps_owner.fee_claim_payment_lines l, fpps_owner.fee_claim_payments p " +
"where " +
"l.fee_claim_payment_id = p.fee_claim_payment_id and p.claim_index = :id";
Query qLinesAvailable = em.createNativeQuery(sLinesAvailable);
qLinesAvailable.setParameter("id", "87167895"); // fails
qLinesAvailable.setParameter("id", 87167895); // fails
List<Object> out = (List<Object>) qLinesAvailable.getResultList();
BigDecimal x = (BigDecimal) out.get(0);
Returns 0 records. Using .getSingleResult() also returns 0 records.
What am I missing here?
Any help would be GREATLY appreciated!
If you are not seeing any malformed query errors, it seems like the parameter is not binding correctly.
To debug, I'd print out that SQL statement the line after you set the parameter. This is the only way you can see the SQL after the parameter is set in order to compare it with Toad.
What does your binding file look like? Maybe you have a different name in there for the ID, so it's not able to find it based on the name. Trying binding with the parameter's order value, just as a test.
This might give some ideas: http://www.mkyong.com/hibernate/hibernate-parameter-binding-examples/
Best of luck! We've all been there :)
What happens when you try:
(Number) query.getSingleResult();
Your query isn't returning a list, but rather just a count.
Good luck.
This is giving me a headache. I have this link query here that grabs an ID
Dim mclassID = From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID
And then later on I have this linq query
ViewData("Staff") = From t In db.Staffs Where t.ClassID = mclassID Select t
Any help would be much appreciated. I've tried quite a few things but to no avail. I've attempted casting, converting, Is operand, etc.
The problem is that myClassID is an anonymous IQueryable. You need to force it into another type (List is my favorite), and then pull it out of that type. So if you were to select it into a List(Of Integer) you could then extract the First() one since it would be the only. You could try something like this:
Dim myClassIDList As List(Of Integer) = New List(Of Integer)( _
From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID)
Dim myClassID as Integer = myClassIDList.First()
Just a guess, but would it help to wrap the right-side of the equation in parenthesis? I.e.:
ViewData("Staff") = (From t In db.Staffs Where t.ClassID = mclassID Select t)
Using the Select operator, you can have multiple results returned. If you are only expecting one result (i.e. you are selecting by a primary key), then you can use Single or SingleOrDefault (depending on whether there is guaranteed to be a result) to get just that one.
Dim mclassID = (From x In db.SchoolClasses _
Where x.VisitDateID = _visitdateID _
Select x.ClassID).SingleOrDefault()
You should change this
Dim mclassID = From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID
to select a single instance or the first instance, otherwise it does as its reporting, returning an IEnumerable, which causes your error later.
Or you could change your second statement to something like
ViewData("Staff") = From t In db.Staffs Where mclassID.Contains(t.ClassID) Select t
taking advantage of the mclassID as an IEnumerable of int.
You can see the errors in Output if you set appropriate options: -
Navigate VS2010 menus to Tools/Options/Projects and solutions/Build and Run/
Set MSBuild Project build output verbosity to "Detailed"
I had a similar error that wasn't showing in the Error list, but with this options setting I saw: -
error BC30452: Operator '=' is not defined for types 'System.Nullable(Of Integer)' and 'Integer'.
from this statement: -
If tqGDBChart.UserIsGroupAdmin(Userid, Groupid) = 0 Then 'User is not a group admin for this group
Easily fixed it with an intermediate variable.
Dim GroupAdminCount As Integer = tqGDBChart.UserIsGroupAdmin(Userid, Groupid)
If GroupAdminCount = 0 Then 'User is not a group admin for this group
have you tried:
ViewData("Staff") = From t In db.Staffs Where t.ClassID.equals(mclassID) Select t