I have a combo with 6 text NA,PO,FA,GO,VG,EX and I want to do a Linq query upon the selected value in this combo used as field in the where clause. for example:
'if "NA" is selected :
Dim query = from t in db.table where t.NA > 0 Select t
'If "PO" is selected :
Dim query = from t in db.table where t.PO > 0 select t
How to do this in elegant way without writing 6 if statement or using "Select case"
How to use a databound combo box to display one field in the drop down, and another as the combo box text on roll up? Using VS 2005... For example, I have a datatable that has 2 fields. One called "ShortDesc" and one called "LongDesc". I want to be able to see the "LongDesc" column values in the drop down on the combo box. When I make a selection, I want the text in the combo box to read the corresponding "ShortDesc" value.
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I have a form that has a combo box and a sub form which displays as a datasheet or aka. datagrid. I would like as i type text into the combo box that the datagrid scroll to the matching record.
View 9 Repliessaving data from a text field and multiple combo boxes to a file on a server in visual basic 2008
View 1 RepliesPretty new to VB.Net. Having a bit of trouble here with something I though should be simple.Keeping it simple. Let's say i have a Document table with "Name" that I want to search on (in reality there are several other tables, joins, etc ..). I need to be able to build the query where clause based on string values passed in.
Example - user may pass in "ABC" or "ABC DEF" or "ABC DEF GHI".The final query would be (syntax not correct i know)Select * from Documents Where Name Like %ABC% AND Name Like %DEF% AND Name like %GHI%
So, I though I could do something like this.
Dim query = From document In _context.Documents
<< loop based on number of strings passed in >>
query = query.Where( ... what goes here?? )
For some reason, being brain dead or something, I can't figure out how to make this work in VB.Net, or if I'm doing it correctly.
Dim dataContext As New ACSLostFoundEntities()
Dim query = From s In dataContext.FosterForms() _
Join c In dataContext.Fosters() _
On c.License Equals s.License _[code]....
At the end of this I want to do a Where WantedPets.Contains(criteria), is this possible?
I have the following linq query:
Dim q = From definition In definitionList _
Where definition.ValueDefName.Contains(criteria)[code]....
I have already looked into this answer: LINQ - dynamic WHERE clause?Unfortunately, it doesn't work for me using .net 4.0. When I attempt to pass the criteria string in it ask for a predicate. The end goal is to add any of these:
definition.ValueDefname.Contains(criteria)
definition.ValueDefDesc.Contains(criteria)
definition.Aliaslist.Contains(Criteria)
definition.StrategicInitiative.Contains(Criteria)
to be passed into the query depending on what checkboxes the user has selected. How can I create a dynamic where clause in linq to sql? Is there new syntax for passing in a where clause as a string?
I'm need to do the equivalent of a t-sql statement like this using LINQ:
SELECT * FROM mytable WHERE idnumber IN('1', '2', '3')
so in LINQ I have:
Dim _Values as String = "1, 2, 3"
Dim _Query = (From m In mytable Where idnumber = _Values Select m).ToList()
Not sure what to do with _Values to make idnumber evaluate each value in the string.
Whats wrong with the below query, I am getting this error: Nullable object must have a value.
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I have following code that creates Linq query.
I've never used Linq until today and having problem with "Order By Clause"[code..]
If I run the code, I get following error.Name 'p' is either not declared or not in the current scope. How come p!Weight in "Select Clause" works but not in "Order By Clause"?
Let's say I have Plans and Documents
Dim myPlans = _context.Plans.Where(predicate1)
Dim myDocuments = _context.Documents.Where(predicate2)
I have structured the where clause for each using PredicateBuilder. So, myPlans and myDocuments have a correct SQL statement. What I'd like to do is join these two tables into one linq statement. The problem I'm having is that, by default the AND condition is joining the where clauses.
myPlans Where clause : (p.name like "%test%" AND p.name like "%bed%") OR (p.description like "%test%" AND p.description like "%bed%")
myDocuments Where clause : (d.name like "%test%" AND d.name like "%bed%") OR (d.description like "%test%" AND d.description like "%bed%")
When I combine the two the desired result Where clause is:
Where (d.ID = p.ID) AND
(myplans where clause above) OR (mydocument where clause above). Meaning, I'd like the two where clauses in each of the tables to be "or" instead of "And".
The current result where clause is:
Where (d.ID = p.ID) AND
(myplans where clause above) AND (mydocument where clause above). Meaning, I'd like the two where clauses in each of the tables to be "or" instead of "And".
I'm forming the statement like this:
Dim test = From d in myDocuments _
Join p in MyPlans on d.ID Equals p.ID _
Select d.Name, p.Name
Right now our queries can be driven through the DataTable Select statement. However, utimately we want to end up with more complex queries. We think Linq is the answer, but can't find anyexamples of this.Here is the sysnopsis:I have a dataset containingdatatable(s) of informationI have a datatable containing business rules as strings like:
(ISNULL(MEMLNAME, '') = '')
(#1880/01/01# <= CONVERT(BIRTHDATE, 'System.DateTime') AND CONVERT(BIRTHDATE, 'System.DateTime') <= #2009/12/31#)
[code].....
So I have a query I'm doign where, at the moment, the places to search are set in stone, but the values that maybe be searched for is variable.Right now, I have a drop down menu that allows you to choose a character class. This limits the items to a specific class. Then I can filter on text from a textbox.
However, each item in the list has a source, based on the book it is published in. I want a user to be able to choose several from a checkbox menu, then pass those values for inclusion in the criteria for finding items.
The problem I'm having is finding the most concise way to do dynamic WHERE clauses. There are several examples out there, and even a couple don't seem to want to do exactly what I'm doing, and I'm having trouble determining if it will work for me.
My LINQ query:
Dim groupedData = (From p In pData _
Group By p.TruncParam Into Group) _
.SelectMany(Function(g) g.Group) _
.Select(Function(d, idx) New With { _
[Code]...
When the TruncParam changes, I would like the index (idx) in the Select clause to reset to 1. So, in the list above, the Index should be SOLUB0001, SOLUB0002, INSOL0001, INSOL0002...CLRES0001, SUMCA0001, SUME0001.
How should I alter the LINQ query?
I have the following xml:
<Root>
<Result img="1.png" name="a">
<Programs>
[Code].....
What is wrong with linq query. Why does a 1 work but a 2 does not? I would also like xml structure preserved after filtering.
Here's what I want to do:
Dim queryX = From m In db.Master
Where m.Field = value
Group Join d In db.Detail
On m.Id Equals d.MasterId Into Group
Where d.Field = value
In English, I want to join the master and detail tables, specifying conditions on each. But this causes the following compiler error:
"Name 'd' is either not declared or not in the current scope."
It works if I put this same condition in functional form:
Group Join d In db.Detail.Where(Function(x) x.Field = value)
but I think this is more typing, harder to understand, and introduces that irritating dummy variable. I really would prefer to use the query comprehension syntax. Is there a way to accomplish this?
I am trying to query for records where that column IS NULL:
Dim UnassignedSubSvc =
From c In CurrentContext.SubService
Where c.Product.ProductSubServiceId **is null**
Select c).ToList()
I have a LINQ to sql statement that joins 2 tables. I would like to add a order by clause on one of the columns. However the order by clause does not seem to take effect at all. right syntax in VB.net to achieve order by in the following:
Dim query = From dtIt In dbsomecontext.mytable
Join dtIl In dbsomecontext.anothertable On dtIt.ItemID Equals dtIl.ItemID
Where dtIl.IsAvailable = True
Order By dtIt.manufacturer
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i want to use a if, then statement in a where clause in linq to sql. Is this possible? I'm trying to achieve the following:
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I'm trying to only add the And If if intLink_pk > -1. If it = -1, then i don't want the and clause at all. Is this posssible within the linq to sql itself?I understand i can write 2 entirely different selects, but if I can't get this done, I may have to write about 50 of them as I want to use multiple Ands if certain conditions are met on the form, such as chk boxes etc.
how to translate a simple SQL LEFT OUTER JOIN with a two condition where clause into a working Linq-to-Entities query. There are only two tables. I need values for all rows from Table1, regardless of matches in Table2, but the WHERE clause uses fields from Table2. In SQL, the two parameters would be Table2WhereColumn1 and Table2WhereColumn2, and the query (which works) looks like this:
SELECT t1.Table1Id,
t1.FieldDescription,
t2.FieldValue
[code].....
I've tried using Group Join with DefaultIfEmpty(), as well as an implicit join (without the actual Join keyword), and I only get rows for items that have values in Table2. I'm sure this won't help, but here's an example of the Linq I've been trying that doesn't work:
Public Shared Function GetProfilePreferencesForCedent(ByVal dc As EntityContext, _
ByVal where1 As Int32, _
ByVal where2 As Int32) _
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I am currently writing a program that needs the use of a database. At the moment I am trying to get a simple combobox working.The problem I am having is that I have never done any work with databases and VB08.I am using an access database that has the fields SMTP, Port, SSL
I want to populate a combo box with the field SMTP and from there I want 2 other labels to be filled in with the port and ssl details I was wondering a) How do I set the connection up with Visual Basic (within the database I am using MySQL to get the information) b) How do I go about populating the combo box?
I have a databound ComboBox on my form. Is there any way that I can make the first field blank.
I can do this with a DropDownList in the HTML part of .Net but is there a way to do it for a ComboBox?
How to take a value from a combo box and have it update a field in sql table?
View 1 RepliesIf there are fields in a combo box as i press the drop down arrow. and if i select a field... then it should not b deleted using a backspace or anyother key..
View 3 RepliesI am trying to use a Linq Query to pull Data from a Dataset and put it into a Combobox. I am getting a Cannot Convert Type String to Boolean Error and I don't understand Why. So Far I have my Linq query pulling Data from the Dataset but I have not been able to get it into the combobox.[code]The portion of code commented out is what I tried before but to no avail. I believe that the error that is occurring, the LINQ query is pulling all the elements not just the VehicleType. I also was wondering how to use the Distinct Keyword in LINQ, from my searches it seems that it should go after my Select Statement in a new Linq, but my SQL Side says thats wrong.
View 3 RepliesI've got the following ADO.NET Entity Framework Entity Data Model:I want to find all the Policyholders with both a Service of a given Id and also a Keyword of a given Status.
This LINQ Does Not Work:
Dim ServicesId As Integer = ...
Dim KeywordStatus As Integer = ...
Dim FoundPolicyholders = From p As Policyholder In db.PolicyholderSet.Include("Keywords").Include("Services") _
Where p.Services.Id = ServicesId _
And p.Keywords.Status = KeywordStatus _
Select p
The Where clause cannot search the p.Services and p.Keywords EntityCollections in that way.
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search the collection of a collection in my LINQ Where clause?
View 11 RepliesI'm getting the following error:"Incorrect syntax near 'Sysco' " when running the following statement using SqlDataAdapter:[code]
View 2 RepliesI am using database compact and i loaded it on my form and i want to update a single field but I cannot, why:
what am doing is:
dim newrec as datatable=(studentdataset."TableName")
dim querie= from det in newrec.asnumerable() _
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I am making a world clock app that relies on an internet response... I have made a situation where it sends the latitude and longitude to a website and the website generates a response in the form of an xml file in a webpage... Here is a demo:
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