Dapper

Stored procedure

CREATE OR ALTER PROCEDURE [dbo].[CreateTrackEntry]
  @EntryDate DATE,
  @SleptAt DATETIME2,
  @WokeUpAt DATETIME2,
  @NapInMinutes SMALLINT,
  @TotalWorkInMinutes SMALLINT,
  @Remarks NVARCHAR(1000) = NULL,
  @TrackEntryId INT OUTPUT
AS
BEGIN
   -- code removed for brevity

END

We have a stored procedure that returns TrackEntryId as an output parameter. Let’s see how can we execute it from the dapper?

using IDbConnection connection = new SqlConnection(_connectionString);

var parameters = new DynamicParameters(trackEntryToCreate);
// Input params
parameters.Add("@EntryDate", trackEntryToCreate.EntryDate);
parameters.Add("@SleptAt", trackEntryToCreate.SleptAt);
parameters.Add("@WokeUpAt", trackEntryToCreate.WokeUpAt);
parameters.Add("@NapInMinutes", trackEntryToCreate.NapInMinutes);
parameters.Add("@TotalWorkInMinutes", trackEntryToCreate.TotalWorkInMinutes);
parameters.Add("@Remarks", trackEntryToCreate.Remarks);

// output params
parameters.Add("@TrackEntryId", dbType: DbType.Int32, direction: ParameterDirection.Output);

await connection.ExecuteAsync("CreateTrackEntry", parameters,commandType:CommandType.StoredProcedure);

int trackEntryId = parameters.Get<int>("@TrackEntryId");

Isn’t it already described in Dapper docs? Sure it is. Why do I bother to write this? Am I just wtiting it for the sake of “posting”? No, I am not. Actually, I was trying to write the code by using Dapper’s docs. Unfortunately, I ran into a few bugs. I am using .NET 9, by the way and this is not even a blog post; it’s just a code snippet. I thought I should share it, may be someone else is facing the same problem as me.

💻Source Code: https://github.com/rd003/PostgressDapperDemo

Tools and technology used

• VS Code (editor)
• .Net 8
• Postgres
• Dapper

Let’s get started with creating the database first.

create database PersonDb;

Now, create a table within the database.

create table Person
(
 Id serial primary key,
 Name varchar(30) not null,
 Email varchar(30) not null
);

To create a new project you need to run these commands in a sequence.

> dotnet new sln -o PostgressDapperDemo

> cd PostgressDapperDemo

> dotnet sln add .\PostgressDapperDemo\

> code . #this command will open this project in the vs code

Nuget packages

Install the following nuget packages.

Dapper is a micro ORM for database connectivity in dotnet and it’s been around for quite a while. It is loved by most of the developers because of its simplicity and performance.

Why dapper?

With the help of dapper you can quickly access the data without writing too much code. It performs very well because we directly write queries and executes them. Developers who loves to work with queries and for the projects, where performance really matters where you wants to write very optimized queries, dapper can be the good choice.