Dapper Tutorial - Knowledge Base (KB)
100 results
How to use attribute mapping with Dapper?
I try to map my Id fields with the Column Attributes but for some reason this doesn't seem to work and I can't figure out why. I set up a test project to demonstrate what I am trying....First, I got my 2 entities:...Entity Table1...using System.Data.Linq....
asked by Cornelis
In Dapper, how to execute a stored procedure without parameter?
I'm using ...Dapper... (thanks ...Sam..., great project.) a micro ORM with a DAL and by some reason I'm not able to execute stored procedures with input parameters. ...In a example service I've the following code: ...public void GetSomething(int something...
asked by antao
How can I use Dapper and send a string to SQLServer as NULL?
I've got a scenario where a string in C# can be ...null.... I need it to be ...NULL... on SQLServer....I'm sending it to SQLServer using Dapper with a query like:...connection.Query<MyObject>("[dbo].[sp_MyStoredProcedure]"), new { StartDate: startDate...
asked by crush
How to use CancellationToken with Dapper async methods?
I'm using Dapper 1.31 from Nuget. I have this very simple code snippet,...string connString = ""; string query = ""; int val = 0; CancellationTokenSource tokenSource = new CancellationTokenSource(); using (IDbConnection conn = new SqlConnection(connString...
asked by Pedigree
How to use Dapper to return a list of dynamic types (list<dynamic>)?
I have been using Dapper.net for a while now and its a very good ORM mapper which works great with .Net dynamic types....But I noticed that when Dapper retrieves data from a database it returns as ...DapperRow... type....Is there are any way that I can re...
asked by Husni Jabir
How to use Dapper with code first?
My personal preference for the current application which I am working is to go with ORMs for this purpose....I haven't used any ORMs yet and I have little knowledge about EntityFramework. Recently I heard of Dapper and have thought of using it....My quest...
asked by shanmugharaj
How to use Dapper to implement the Unit Of Work pattern?
Currently, I am trying to use Dapper ORM with Unit Of Work + Repository Pattern....I want to use Unit of Work as opposed to a simple dapper Repository due to the fact that my insert and updates require a degree of transaction processing. I have been unabl...
asked by Stig
What best practices to use for connection and query in Dapper?
So i've read a bunch of links/SO questions, but i still can't get a clear answer on this....When performing SQL queries with Dapper in an ASP.NET application, what is the best practice for opening/closing connections?...Here's the pattern i'm currently fo...
asked by RPM1984
Why with Dapper I get a declare the scalar variable error?
I am experiencing issues when trying to used a paramaterized query in Dapper. I have found a number of other users with similar issues but have not been able to resolve the issue....The code... public User GetUser(int employeeId) { var args...
asked by davidk
In Dapper, how can I update several entries in one sql statement?
I am attempting to use one single Update statement to update multiple records with different values (I'm not trying to update many rows to have the same values which is pretty straight forward). Here's what I'm trying right now:... using (var cn = Get...
asked by Kento
How to pass Table Valued Parameters with Dapper Dynamic Parameters?
I was trying to create a generic method, which can read the parameters name and value from a class at Runtime and create parameter collection for Dapper query execution. Realized that till the point all parameters are Input type it works well, but if I ha...
asked by Mrinal Kamboj
Why using Dapper I get an issue with Oracle stored procedure with refcusors as out parameter?
Given this oracle stored proc package:...CREATE OR REPLACE PACKAGE TESTPKG AS FUNCTION TestReturnRefCursor RETURN SYS_REFCURSOR; PROCEDURE TestingRefCursorsAsOutParam (outp OUT SYS_REFCURSOR); END TESTPKG ...And this package body:...CREATE OR REPLAC...
asked by J.T. Dorion
How with Dapper to automatically map output parameters?
I've been using Dapper to call stored procedures passing it an object. For example:...If I have an object:...public int ID { get; set; } public int Year { get; set; } ...I can create this object and pass it to my ...Execute... call as the parameters. ...
asked by Alex
Using Dapper, how to map a string column to a generic list?
I have the following model:...public class Model { public string Name { get; set; } public List<int> Numbers { get; set; } } ...And an ...SQL... query that returns the following dataset containing two nvarchar columns:... Name | Numbers 'foo' | '1,...
asked by Mugen
Why Dapper return an assembly reference is missing for SqlConnection?
I'm still new to MVC and dapper ORM. Suppose I use dapper for MVC and and when I try to build solution, it showing message: 'SqlConnection does not contain a definition for'Query' and no extension method 'Query' accepting a first argument of type 'SqlConn...
asked by Botski
How to use an Enum as string in Dapper?
I am trying to use ...Dapper... and ...Dapper-Extensions... and to serialize my ...enums... on the database as ...string.......Right now they are serialized as integers (inside a ...VARCHAR... field) instead....Is there any way to do this? Any custom typ...
asked by MaurGi
How to use QueryMultiple method to allows you to get a result and a count at the same time in Dapper?
I wrote two segments of SQL command and want to process in one query like this:...SELECT COUNT(*) FROM books SELECT * FROM books ORDER BY bookID OFFSET 1000 ROWS FETCH NEXT 10 ROWS ONLY ...How can I use ...conn.QueryMultiple... method to get ...count... ...
asked by ineztia
How in ASP.NET Web API and Dapper, do you send an array of arguments?
Creating a Web API through which array of id is passed and returns the result from the OracleDB....public class SampleController : ApiController { public string Getdetails([FromUri] int []id) { string inconditons = ""; for (int i = ...
asked by trx
Why dapper return ToList() cannot be used in an async method?
I'm trying to change a method to make it async and using Dapper This is the current method in a repository class:...... public class ClientsRepository : BaseRepository { public ClientsRepository(string connectionString): base (connectionString...
asked by Mr_LinDowsMac
How to execute LINQ with Dapper?
I'm trying to convert from Entity Framework to Dapper to hopefully improve data access performance....The queries I use are in the form of predicates like so "Expression>"....To give an example:...I have the following code which I need to convert to using...
asked by Rian Mostert
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