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module DapperFSharp = | |
open System.Data.SqlClient | |
open System.Dynamic | |
open System.Collections.Generic | |
open Dapper | |
let dapperQuery<'Result> (query:string) (connection:SqlConnection) = | |
connection.Query<'Result>(query) | |
let dapperParametrizedQuery<'Result> (query:string) (param:obj) (connection:SqlConnection) : 'Result seq = | |
connection.Query<'Result>(query, param) | |
let dapperMapParametrizedQuery<'Result> (query:string) (param : Map<string,_>) (connection:SqlConnection) : 'Result seq = | |
let expando = ExpandoObject() | |
let expandoDictionary = expando :> IDictionary<string,obj> | |
for paramValue in param do | |
expandoDictionary.Add(paramValue.Key, paramValue.Value :> obj) | |
connection |> dapperParametrizedQuery query expando |
type User = { UserId:string } | |
let getUsers connection = | |
connection | |
|> dapperQuery<User> "SELECT UserID From tbUser" | |
let getUser userId connection = | |
connection | |
|> dapperMapParametrizedQuery<User> "SELECT UserID From tbUser WHERE UserId = @UserId" (Map ["UserId", userId]) | |
|> Seq.head | |
type UserSelectArgs = { SelectedUserId:string} | |
let getUser' userId connection = | |
connection | |
|> dapperParametrizedQuery<User> "SELECT UserID From tbUser WHERE UserId = @SelectedUserId" {SelectedUserId=userId} | |
|> Seq.head |
Nice!
great!
Can anyone comment on how this compares to FsSql? -> https://github.com/mausch/FsSql
Seems similar at a glance.
Awesome
This looks great! I was wondering whether you could help me out here. When I run this in and try to print out something like the "getUsers" over my data all I get is<fun:users@187>
. I've tried iterating with Seq.iter
and Seq.map
for individuals printing. I even had to cast the items with Seq.cast
and I'm getting errors that my expression isn't finished even when I call something like Seq.head
on the last pipe. What am I not understanding?
incomplete, created these two files in f# and imported Dapper in PM and red squiggles all over!
I found this example very helpful but I needed one more thing to get it all working with Dotnet Core 2.1.3: the result types have to be annotated with [<CLIMutable>]
in order to give the record a default constructor with property getters/setters.
Also, I noticed that passing the Map directly in dapperMapParametrizedQuery
works fine without having to create an Expando. That function turns into a one-liner. Not sure if this is specific to the 2.1.3.
@ovatsug25, it sounds like you're only partially applying the function. Are you sure you passed all the arguments, like the connection
argument as well?
What do you think about this?
https://github.com/AlexTroshkin/fsharp-dapper
https://www.nuget.org/packages/FSharp.Data.Dapper
It would be nice if the sample script included an example of how to run the functions (including a sample connection string).
This looks useful. I'm trying to port a C# Dapper library using the Unit of Work pattern which is how I ended up here. What's missing (for me) is a way to wrap this up with transactions.
Definitely would be a plus to add the "chrome" around these snippets. They're very helpful. New users can add
open System.Data.SqlClient
open Dapper
open Npgsql
let connString = "Host=localhost;Database=exampleDB;Username=postgres;Password=example"
let connection = new NpgsqlConnection(connString)
connection.Open()
Note: You'll also need to install Npgsql: dotnet add package Npgsql --version 3.2.7
if you're using Postgres, like I am.
I found this via a google search ;)