Dapper Tutorial - Knowledge Base (KB)
43 results for: in tag: linq
How do I rewrite this to be more LINQy?
I have this set of data here. Events has a property ...EventGroups... that is of type ...List<Groups>...List<Events> e; List<Groups> g; // Get the data from the database using dapper using( var con = DataAccessMaster.GetOpenConnection( ) ) { using( v...
asked by jcolebrand
Dapper parameterised queries with LINQ autogenerated types
I'm using a combination of LINQ and Dapper in my work. I'm replacing my LINQ code with Dapper in places for performance reasons. I have a lot of LINQ data objects created by dragging and dropping into the Visual Studio database diagram from SQL Server..
asked by Giles Roberts
Why doesn't Select() convert a IEnumerable<dynamic> to IEnumerable<StrongType>?
I'm trying to use Dapper simply to map my database tables to types in C#, however, some of my types need additional elements that are not in the table. To do this I am using a factory that can take column values and set the appropriate properties....publ...
asked by Doug Wilson
Using Contains() on an IQueryable built with Dapper (with MVCContrib Grid)
I've got the following ActionResult in a ASP.NET MVC 3 project:...public ActionResult Index(string searchWord, GridSortOptions gridSortOptions, int? page) { var userListModel = new PagedViewModel<UserModel> { ViewData = ViewData, Q...
asked by Nick
Creating a two dimensional array from a Dapper result
Is this the least amount of code I can use to convert a Dapper query result to a two dimensional array?...var array = cn.Query(@"SELECT Id, Desc FROM Things") .Select<object, ArrayList>(d => { return new ArrayList {((dynami...
asked by Kev
LINQ Expressions Body ToString
I'm wondering if somebody can explain to me the downside of retrieving...(Expression<Func<T, bool>>) Expression.Body ...at runtime and operating on this as a string?...for example given the following...public partial class Tests : Form { public Tests(...
asked by Brett Smith
Why does using Linq's .Select() return IEnumerable<dynamic> even though the type is clearly defined?
I'm using Dapper to return dynamic objects and sometimes mapping them manually. Everything's working fine, but I was wondering what the laws of casting were and why the following examples hold true....(for these examples I used 'StringBuilder' as my know...
asked by BlackjacketMack
Project dynamic Dapper results excluding some properties
Given a dynamic Dapper query such as:...var results = connection.Query<dynamic>("SELECT ...."); ...I want to remove a couple of the returned columns/properties from the results. The trick is I want to do this without knowing/caring the names of the proper...
asked by Brian Vallelunga
How to use Multi-Mapper to create multiple one to many object hierarchy
I have my 2 models like below ...public class FItem { public FItem() { } public int RecordId { get; set; } public int MarketId { get; set; } public string ItemName { get; set; } publi...
asked by Kuntady Nithesh
one-to-many insert using dapper dot net
I have seen here...How to insert an IEnumerable<T> collection with dapper-dot-net...how dapper is able to handle ...IEnumerable... as an input param and dispatch multiple commands for each member of the collection....In my case I have an ...IEnumerable<in...
asked by Pricey
alternatives for Sqlinq to create sql queries from linq
Sqlinq... is an opensource project to create sql queries from linq. I'm using it with ...Dapper..., but unfortunately it doesn't support JOINs. ...Is there are any other libraries that do the same thing and supports JOIN too?...If not, what could be a so...
asked by mohsen dorparasti
Join navigation property with line
I try to join a navigation property by using LINQ. This is my code... var activities = Using<GetActivitiesForUser>() .Execute(User.DisplayAs, User.MarketId); var contacts = Using<GetContactsForUser>() .Execute(User.DisplayAs, User....
asked by Nils Anders
How to convert List<Dapper.SqlMapper.FastExpando> to runtime type (List<IDictionary<string,object>>)
I'm using a method that has a return signatur of ...IEnumerable<dynamic>.... At runtime for a particular call it is returning ...List<Dapper.SqlMapper.FastExpando>.......var x0 = repo.Find(proc, param); //x0 runtime type is {List<Dapper.SqlMapper.FastExp...
asked by Jay Walker
dapper aggregation function error
have this aggregation function in my code using Dapper ...var sql = (@"SELECT * FROM [pubs].[dbo].[authors] as a right join pubs.dbo.titleauthor as b ON a.au_id = b.au_idT"); var data = connection...
asked by MuhanadY
Checking for duplicates before updating with dapper linq c#
I'm relatively new to Linq and Dapper and I'm trying to find the most effecient way to make an insert happen. I have a list object that looks like this: ...public class Programs { public int Id { get;set; } public int Desc { get;set; } } ...The li...
asked by Elaine K
dapper linq Object reference not set to an instance of an object
I have simple customer table that has 4 records, and only one has email...public string Username { get; set; } public string Email { get; set; } ............ var data = cn.Query<Customer>("select * from customer"); var aaa= data.FirstOrDefault(f => f.E...
asked by nam vo
Dynamic Linq on Dapper dynamic collections - possible?
We are investigating using LinQ to query an internal dynamic collection created by Dapper. The question is:...How to execute dynamic LinQ against the collection using Scott Guthrie dynamic linq (or some other technology if possible)? (...http://weblogs.as...
asked by user2512533
Populate list from linq query result
I have the following code, I'm returning results that are associated with the userId, I then want to loop through the results and build a collection and return it back to the UI.... public List<UserEmails> LoadUsersInbox(Int64 userId, int status) { ...
asked by Code Ratchet
Get First Single matched element or First if there's no match?
Is that possible in ...LINQ... to write a nice one-liner to get a ...first matched element or if there's no match than get first element... in the collection?...E.g. you have a collection of parrots and you want yellow parrot but if there's no yellow parr...
asked by user1249170
Dapper nested object query - not populating all properties
I am trying to return a flat result set into a nested object with Dapper.NET (EmergingIssue contains both Reason and Status objects), but the query is not populating all the columns. See POCOs below:...public class EmergingIssue { public string Catego...
asked by user1077685
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