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'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.
[Code]...
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.
I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.
For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.
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]...
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 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.
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)
View 1 RepliesI 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
View 4 RepliesHow should I create between clause in my query?
View 3 RepliesI 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?
View 1 RepliesI've written an SQL query with a lot of 'or's in the 'where' clause: i.e. "SELECT * FROM myTable WHERE col1='a' or col1='b' or col1='c'...etc" I'm trying to run a query in access via vb.net, but I keep getting "Query is too complex" error message. I'm guessing I've hit some maximum limit. Anyone know a way around this, other than just to break it down into multiple queries?
View 5 RepliesI want to set data binding source filter. I want to show only 10 results in descending order by date column.
I know how to use TOP clause in ordinary 'sql' query, but I don't know how to set up filter to binding source.
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
[Code]...
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.
I'm currently trying to loop through an array (two values) and use both values in a query inside the loop Right now my code doesn't work. I'm trying to populate dynamically the "appType" parameter within the "SelectParameters" tags of the SQLDataSource, but this won't work.
[Code]...
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"
I am using VS2010 windows application , SQL server 2008 express at backend.I am designing a windows form with fields to search records in database.Say there are 3 fields in the form :
1) material no 2) material group 3)creation date the corressponding table in database with above fields is " Material_master" User can search materials in the database by entering any of the above fields.No I want to write a query where if user doesn't enter anything then my query should work like
"select * from materialmaster "
if only material no is enterd at screen then
"select * from materialmaster where MatNo = materialno "
if both date of creation and material no enterd then
" select * from materialmaster where MatNo = materialno and Date = creationdate "
In other words , field with no values in it should not be accounted in the where clause. Only one query I want to write.How we can achieve this in VB.net windows application?
I'm adding queries to a wizard generated Table Adapter with WHERE condition that involes the "%" wildcard:
SELECT * FROM Customers WHERE Country = @Country AND CustomerID LIKE @CustomerID
--If I add % after @CustomerID, I get an error message that the --query can't be parsed but if I run the query as above it returns all --the rolls irrespective the value I supplied for the CustomerID column.Only performance counts!
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].....
I've got two tables:
tClient:
ClientID Name=============1 John2 Sally3 Joe4 Nick
tInvoice:
InvoiceID ClientID DateAdded==========================1 1 2010/09/012 1 2010/09/023 3 2010/09/01
I'm trying to write sproc where I need the following info:
[Code]...
I built a prototype system with some database queries. Since it was just a prototype and I was very new to databases, I just used a direct string. This is the string I used and it works fine:
command = New OleDbCommand("SELECT * FROM " + prefix + "CanonicForms WHERE Type=1 AND Canonic_Form='" + item + "'", dictionary_connection)
Now, in putting it in a real system, I wanted to use the more secure parametized method, so after some googling I came up with this:
command = New OleDbCommand("SELECT * FROM @prefix WHERE Type=1 AND Canonic_Form=@form", dictionary_connection)
command.Parameters.AddWithValue("@prefix", prefix + "CanonicForms")
command.Parameters.AddWithValue("@form", item)
But all I get is an error for an incomplete query clause. What have I done differently between the two?