.Net Linq - How To Append A Where Clause

Apr 23, 2009

Pretty 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.

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Where Clause On This LINQ Query

Nov 25, 2009

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?

Asp.net - Make A Dynamic Where Clause: Linq To Sql?

Jun 28, 2011

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?

C# - Linq Query With Dynamic Where Clause?

Apr 13, 2012

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.

Iif Condition In Linq Query Where Clause

Aug 25, 2011

Whats wrong with the below query, I am getting this error: Nullable object must have a value.

[Code]...

Linq To DataSet Order By Clause

Feb 7, 2012

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"?

LINQ To SQL And Join Two Tables With OR Clause

Apr 23, 2009

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

VB Dataset Linq With String Where Clause?

Mar 17, 2009

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].....

VS 2010 LINQ To XML Customizable WHERE Clause?

Jun 13, 2012

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.

.net - Reset Index In LINQ Select Clause?

Mar 13, 2012

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?

Asp.net - Linq Where Clause Not Producing Expected Results

Nov 8, 2011

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.

Can't Use A Where Clause On Both Tables In A LINQ Group Join?

Jun 7, 2011

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?

Compare Nullable Types In WHERE Clause Of Linq To Sql .NET?

May 4, 2012

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()

Syntax For Order By Clause In Linq To Sql That Has Select New With

May 25, 2011

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

[Code]...

VS 2008 IfThen Statement In Linq To Sql Where Clause?

Aug 19, 2010

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:

[Code]...

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.

.net - Substitute Field Name In Linq Where Clause By Combo Text?

Jun 22, 2012

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"

.net - Linq-to-Entities: LEFT OUTER JOIN With WHERE Clause And Projection?

Oct 18, 2010

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) _

[code].....

.net - Search The Collection Of A Collection In LINQ Where Clause?

Apr 15, 2009

I'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.

[Code]...

Search The Collection Of A Collection In LINQ Where Clause?

Apr 15, 2011

search the collection of a collection in my LINQ Where clause?

View 11 Replies

Sql Query Where Clause And .net

Mar 11, 2010

I am learning how to use database. I am using sql server 2005. I would like to know how to make an sql query to the database from vb.net. I have tried some code. what i would like to know is, how to make the sqldataadapter statement with 2 or more where clause.

[Code]...

Where To Put Parameters That Have Set After Where Clause

Sep 6, 2011

I am trying to use the following query Dim sqlQry As String = "SELECT * FROM tblTest where Name=@NM and Rank=@RN"..Then I fill my dataadapter by Dim dAdt As New SqlDataAdapter(sqlQry, conStr) But do not know where to put the parameters that I have set after where clause.

.net - Optional Where Clause In Query?

Jan 27, 2010

I have an application that does a search of our database (exposed via EF) for records meeting certain conditions. We have two main tables (Jobs and Recipients). Recipients are linked to the Jobs table by a Job ID.The job record has various fields (Process Date, NameJobType). The recipient has a lot of Name and ID fields (e.g. Account Number, Surname, etc)

Add Where Clause To A Table Adapter?

Feb 28, 2012

I have a dataset setup by using the Visual Studio wizard and in the form is this line of code:

Me.StudentsTableAdapter.Fill(Me.StudentsDataSet.Students)

The select statement for the table adapter is[code]...

Can you tell me how to add a Where clause using coding on this table adapter?

C# - ASP.NET - Advanced Where-Clause In LinqDataSource?

Oct 21, 2010

I have two tables:Orders OrderProducts - An order can have 1 to many orderProducts records associated with it.What I am trying to do (unsuccessfully) is to implement a GridView search using a LinqDataSource wherein the search returns Order results where any of the OrderProduct.Manufacturer columns contain a search query.

I was hoping the following would work, however it seems lambda expressions do not work within a Where clause of a LinqDataSource (in VB):

[Code]...

how to get this working within the LinqDataSource definition, or will I have to handle and set up a custom OnSelecting event?

Error In FROM Clause : Near 'COMPANY'

Sep 1, 2009

I am getting this error when trying to connect to the database which comes with Sage Line 50. It doesn't matter what table i try to look at i get this error when i try to create a datagridview. The near 'COMPANY' bit is the name of the table not one of its fields. Is this going to be something wrong with the SAGE ODBC (wouldn't surprise me) or does something need changing?

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Group By Clause In Sql Query?

Aug 26, 2009

I have a table DailyTransaction in MsAccess as under: DTDate, DTTime, CustId, Description, Quantity, Price, Amount, AccountNumber, Name I want to extend following query with a Group By clause:I require to display all records in a Listview Group By CustId.Then I require to display all records in a Listview Group By AccountName.e how I can extend following query with Group By clause to achieve the required results

How To Create Between Clause In Query

Aug 15, 2010

How should I create between clause in my query?

Merge Parameter Using IN Clause?

Oct 6, 2010

I've develop an email function for my company. Basically the email will be sent to the student if a lecturer have any announcement to made.My company have 2 branches. Btw, all my queries written in the database. There are few fields that contains the queries.

This is my database looks alike :
Table Name - email
Fields : Contains
1. EmailID 1

[Code].....

Multiple Values Into A SQL Where Clause Via VBA?

Mar 14, 2012

I am using visual studio 2010/vb trying to display data that is based on a value read from a text file.Currently i can get it to read a text file with only 1 value and get this value into a label. Then by using a SqlDataSource and setting a parameter in the WHERE clause to use the value from the label, it will display the related data in a data GridView.

BUT i would like to be able to read multiple values seperated by a , or next row down in the text file and enter these values into a WHERE bookID in (value1,value2,...)

Optional Where Clause In Query

Apr 25, 2012

I have an application that does a search of our database (exposed via EF) for records meeting certain conditions. We have two main tables (Jobs and Recipients). Recipients are linked to the Jobs table by a Job ID.The job record has various fields (Process Date, Name, JobType). The recipient has a lot of Name and ID fields (e.g. Account Number, Surname, etc)I want to present a search screen where they see a list of fields to search on. The ASP.net code then sees which textboxes the user typed in (or selected), and builds a query based on that. [code] Where I'm stuck is figuring out how to add in additional where clauses. Should I just use Entity SQL?Can this return strongly typed EF objects as well? And is it possible to return both the Jobs and Recipients objects?

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