Post New Web Links

Join linq queries with same field name

Posted By: Posted Date: September 18, 2010 Points: 0 Category :ASP.Net

Hi everyone-I'm trying to join three Linq queries together. One of the fields (rating) is the same name for each so when I add b.rating as you'll see below, I get a squiggly that says "Anonymous type member or property 'rating' is alread declared. Dim customerCategoryA= (From a In dc.CategoryARatings _ Where a.userID = userID _ Select New With {a.productID, a.rating, a.ratingComment}) Dim customerCategoryB = (From b In dc.CategoryBRatings _ Where b.userID = userID _ Select New With {b.productID, b.rating}) Dim DataForGridview = From p In Products _

View Complete Post

More Related Resource Links

Which tier do Linq queries belong?

Started in middle of a new project. Our design architecture uses an n-tier (not MVC - no controllers) structure with Presentation, Data, Business and Service tiers. However the lead analyst has the majoriety of code all in the Business tier claiming it all contains Business logic. Our data tier is nothing more than a single .dbml model of the primary database to support all of the Linq queries in the Business tier. To my mind Linq queries and classes they use are data access and belong in the data tier but our lead analyst says they contain business logic therefore have to be in business layer.

Data Points: LINQ Projection Queries and Alternatives in WCF Services

LINQ's ability to project randomly shaped data into anonymous types can be a blessing and a source of frustration, says Julie Lerman. It's great when you just need to grab a special view of your data, but it can be problematic in certain circumstances. She explains what the limitations are and how to get around them.

Julie Lerman

MSDN Magazine May 2010

Data Points: Precompiling LINQ Queries

Did you know that by precompiling LINQ queries you might actually be degrading your app's performance if you're not careful? Julie Lerman explains how to ensure you're not re-precompiling queries each time and losing the expected performance benefits across post-backs, short-lived service operations and other code where critical instances are going out of scope.

Julie Lerman

MSDN Magazine March 2010

Toolbox: Easy LINQ Queries, Becoming A Better Developer, And Logging Help

This month Toolbox provides help with error logging, finds an app that helps you write LINQ queries, and explores the non-technical side of development.

Scott Mitchell

MSDN Magazine September 2008

Parallel LINQ: Running Queries On Multi-Core Processors

Use Parallel Language Integrated Query (PLINQ) to take advantage of multi-processor computers and the newer wave of multi-core processors.

Joe Duffy and Ed Essey

MSDN Magazine October 2007

Linq getting data from field on record

Hello,

I would assume this is possiable but I cannot seem to find it anywhere. I just one the contents of a single field, I don't see why I have to return the how

record to get get that information, here is my current code, how can I make this better without returning the entire record, for just getting contents of one field.

var patternrecord = storedb.Patterns_Table.Single(a => a.Pattern_GUID == id);
PMEDIA.Pattern_Key = patternrecord.Pattern_Key;

Linq join fields for return data

Hello,
how would I join fields together?

return (from c in storedb.Product_Categories

                         where c.Category_Name.Contains(searchText)
                         orderby c.Category_Name
                         select new {
                                    c.Cat_GUID,
                                    c.Category_Key && " ;" && c.Category_Name // HOW CAN I DO THIS.....

Time Difference in Linq queries

Hi All,

I have my Linq query in which i need to find time difference(not days difference).

The field in database is datetime.

Dim ldtToday As DateTime = TimeOfDay

Dim SR_RM_InnerJoin = From SR In lcntxRT60Entities.RtSReports _

Join RM In lcntxRT60Entities.RtRMaster On SR.RtRMaster.ReportID Equals RM.ReportID _

Select SR, RM _

Update field Linq

HelloI want to update one field of one record using linq. I use below codeDim p1 = (From p In db.Products_ Where p.ProductID= 1320 _ Select p).Single p1.CategoryID= p1.CategoryID+ 1 db.SubmitChanges()The issue is above query first execute select command and then Update command. and then update all fields of selected record. and this cause overflow to DB.I need to only update one field value. How Coudl I get below sql command. (only update one field)update Productsset CategoryID= CategoryID+ 1where ProductID=1320

Field method missing with LINQ query

H, I want to access the data from datatable object. When i trying to get the fieldslist usng "Field" method. But I could not find the method with my table object. Eventhoguh i forcibly write a method and trying to access the fields, It is giving the below error for the first join in query. Rest of the lines are fine. What is the reason behind it. The errro: "Error 2 'LINQ2DB.SP_VS_OP' does not contain a definition for 'Field' and the best extension method overload 'System.Data.DataRowExtensions.Field<T>(System.Data.DataRow, string)' has some invalid arguments" What is the meaningof the error. Shall i do any other changes in the query line? var QueryChnl = from oSPOP in SPOP.AsEnumerable() join oDiscChannel in DiscChannel.AsEnumerable() on oSPOP.Field<int>("spid") equals oDiscChannel.Field<int>("SPID") join oChannel in Channel.AsEnumerable() on oDiscChannel.Field<in


Categories:

ASP.Net	Windows Application	.NET Framework	C#	VB.Net	ADO.Net
Sql Server	SharePoint	Silverlight	Others	All