Dapper Tutorial - Knowledge Base (KB)
225 results in tag: sql
.NET SqlConnection and SqlCommand
I use SqlConnection and SqlCommand classes in my project with Dapper ORM but I've got a strange problem. When I use SqlCommand for inserting a row in a db table it always work correct and when I select updated data form tables everything is fine but after...
asked by shadeglare
Map string to guid with Dapper
I'm using Dapper to hammer out some load testing tools that need to access a PostgreSQL database. This particular version of PostgreSQL does not support GUIDs natively, so GUID values are stored as 32 character strings. The values are converted to strings...
asked by Marnix van Valen
Does Dapper support the like operator?
Using Dapper-dot-net......The following yields no results in the data object:...var data = conn.Query(@" select top 25 Term as Label, Type, ID from SearchTerms WHERE Term like '%@T%'", new { T = (string)term }); ...Howeve...
asked by Jay Stevens
How do I select an aggregate object efficiently using Dapper?
Lets say that I have a series of objects that form an aggregate....public class C{ public string Details {get;set;} } public class B{ public string Details {get;set;} public List<C> Items {get;set;} } public class A{ public long ID {get;set;} p...
asked by Peter
Dapper multiselect: Nested class primary key doesn't map unless using "AS"
I have two classes:...class Foo{ public int FooId { get; set; } ... public Bar Bar { get; set } } class Bar{ public int BarId { get; set; } public int FooId { get; set } ... } ...when i then run the query like this:...sqlConnectio...
asked by Joakim
Inserting One to Many Entities using dapper
I have following two classes and corresponding db tables. I am trying to insert the full object graph (student with multiple courses). I am looking for an example on how would one do this using Dapper. The Id's are auto-increment identity fields....Cla...
asked by Anil Ali
Parameterized LIKE clause in SQL statement using Dapper
I want to perform the following query using Dapper, which currently doesn't return expected results (I think it must be treating the @pName param as literal text within the single quotes?):...var q = "SELECT * FROM Users WHERE Name LIKE '@pName%'"; ...@pN...
asked by marcusstarnes
SELECT * FROM X WHERE id IN (...) with Dapper ORM
What is the best way to write a query with IN clause using Dapper ORM when the list of values for the IN clause is coming from business logic? For example let's say I have a query:...SELECT * FROM SomeTable WHERE id IN (commaSeparatedListOfIDs) ...Th...
asked by Marko
How to call a L2S provider to translate a predicate in form of Func<T,bool> to a SQL where clause?
I am using L2S in my application but i'm switching more and more to ...dapper.net... because i'm having major issues with query performance and the annoying ...n+1 selects... problem....Its working fine, but i miss the comfortable LINQish style of writing...
asked by Jan
ORM for use with databases that have semi-flexible schema design
I like the "micro" approach of Dapper, Massive, PetaPoco etc. and I like to have control over the SQL we send to the database, most of the time it's relatively simple. I also like working with POCO's however when dealing with a somewhat flexible schema de...
asked by Christian Sparre
Non-parameter SQL Variables with MySql Connector/Net and Dapper?
The code below generates the following error: ...Parameter '@ID' must be defined....Am I doing something wrong or is not it possible to use variables in the SQL query with MySQL which aren't Dapper parameters? ...In this example, @Slug is a Dapper para...
asked by Mike Gleason
Using Dapper to map more than 5 types
I am currently building a SELECT query that joins 12 tables together. I've been using Dapper for all my other queries and it works great. Problem is, the generic methods only have to five generic parameters....I've previously modified the code to support ...
asked by Christian Droulers
C# database access, Dapper, SQL and POCOs - programming design
Let's say we have a table in SQL represented in C# like this:...public class Product { public int ID { get; set; } public string Name { get; set; } public string Picture { get; set; } // filename of the picture, e.g. apple.jpg public int Categ...
asked by walther
Dapper. Execute Query with GOs
I am trying to use Dapper to run a SQL Query:...use master go if exists (select name from sys.databases where name = N'TestDB') drop database [TestDB] go create database [TestDB] on primary ( name = 'TestDB_Data', filename = '$Path\TestDB_Data.mdf'...
asked by Miguel Moura
Dapper not adding parameters
I am trying to use Dapper for our complex queries to remove any lost overhead that was previously existing with NH....I have the following query (note this has been considerably shrunk):...SELECT DISTINCT * FROM tasks t WHERE t.initials = @UserInits ...
asked by Stuart.Sklinar
Dapper GridReader already Disposed Error
I'm using Dapper dot net to execute a stored procedure that returns 4 result sets. Here's how I'm doing it:... public Results Search(Query query) { if (query == null) throw new ArgumentNullException("query"); Results results; ...
asked by Ronnie Overby
Dapper Multi Mapping with QueryMultiple
I have a stored procedure that returns multiple result sets. I'm executing this with dapper....One of the result sets is Person JOIN Checks, where Person can have many Checks....The end goal is to have distinct person objects that have a collection of che...
asked by Ronnie Overby
SQL Query Generator for Dapper
Hi was trying to find the ORM with the best performance to use in our new project. My final choice became Dapper. We also need to have our application to include the following features (at least) which prevent us from hard coding the SQL queries to pass t...
asked by Moslem Ben Dhaou
Disable dapper.rainbow from using ID while inserting
I am using dapper.rainbow for inserting a record into MSSQL db. Following is my code...int? id = db.RoomTypes.Insert(roomType) ...When i run my app, i am getting the below exception....Cannot insert explicit value for identity column in table 'RoomTypes'...
asked by krishnan
What SQL access layer to use for simple reading in Play-Scala?
I will be implementing a read-only web application in Play 2.1 (Scala). Since I'll only be doing reading and marshaling the data read to JSON I would like to avoid any other DSLs and mappings....I've done similar projects in .NET/C# using ...dapper-dot-ne...
asked by jl.
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