RSCG – Dapper.AOT
Generating AOT code for Dapper -hydrating classes from SQL queries.
This is how you can use Dapper.AOT .
The code that you start with is
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net9.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Dapper" Version="2.1.35" />
<PackageReference Include="Dapper.AOT" Version="1.0.31" />
<PackageReference Include="Microsoft.Data.SqlClient" Version="5.2.2" />
</ItemGroup>
<PropertyGroup>
<InterceptorsPreviewNamespaces>$(InterceptorsPreviewNamespaces);Dapper.AOT</InterceptorsPreviewNamespaces>
</PropertyGroup>
<PropertyGroup>
<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
</PropertyGroup>
</Project>
The code that you will use is
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net9.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Dapper" Version="2.1.35" />
<PackageReference Include="Dapper.AOT" Version="1.0.31" />
<PackageReference Include="Microsoft.Data.SqlClient" Version="5.2.2" />
</ItemGroup>
<PropertyGroup>
<InterceptorsPreviewNamespaces>$(InterceptorsPreviewNamespaces);Dapper.AOT</InterceptorsPreviewNamespaces>
</PropertyGroup>
<PropertyGroup>
<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
</PropertyGroup>
</Project>
// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");
var p= Product.GetProduct(new SqlConnection("Server=localhost;Database=AdventureWorks2019;Trusted_Connection=True;"), 1);
namespace DapperDemo;
internal partial class Product
{
public int ID { get; set; }
public string Name { get; set; } = "";
public string ProductId { get; set; } = "";
public static Product GetProduct(SqlConnection connection, int productId) => connection.QueryFirst<Product>(
"select ID, Name, ProductId from Production.Product where ProductId=@productId", new { productId });
}
global using Dapper;
global using Microsoft.Data.SqlClient;
global using DapperDemo;
[module: DapperAot]
The code that is generated is
#nullable enable
namespace Dapper.AOT // interceptors must be in a known namespace
{
file static class DapperGeneratedInterceptors
{
[global::System.Runtime.CompilerServices.InterceptsLocationAttribute("D:\\gth\\RSCG_Examples\\v2\\rscg_examples\\Dapper.AOT\\src\\DapperDemo\\DapperDemo\\Product.cs", 8, 93)]
internal static global::DapperDemo.Product QueryFirst0(this global::System.Data.IDbConnection cnn, string sql, object? param, global::System.Data.IDbTransaction? transaction, int? commandTimeout, global::System.Data.CommandType? commandType)
{
// Query, TypedResult, HasParameters, SingleRow, Text, AtLeastOne, BindResultsByName, KnownParameters
// takes parameter: <anonymous type: int productId>
// parameter map: productId
// returns data: global::DapperDemo.Product
global::System.Diagnostics.Debug.Assert(!string.IsNullOrWhiteSpace(sql));
global::System.Diagnostics.Debug.Assert((commandType ?? global::Dapper.DapperAotExtensions.GetCommandType(sql)) == global::System.Data.CommandType.Text);
global::System.Diagnostics.Debug.Assert(param is not null);
return global::Dapper.DapperAotExtensions.Command(cnn, transaction, sql, global::System.Data.CommandType.Text, commandTimeout.GetValueOrDefault(), CommandFactory0.Instance).QueryFirst(param, RowFactory0.Instance);
}
private static global::Dapper.CommandFactory<object?> DefaultCommandFactory => global::Dapper.CommandFactory.Simple;
private sealed class RowFactory0 : global::Dapper.RowFactory<global::DapperDemo.Product>
{
internal static readonly RowFactory0 Instance = new();
private RowFactory0() {}
public override object? Tokenize(global::System.Data.Common.DbDataReader reader, global::System.Span<int> tokens, int columnOffset)
{
for (int i = 0; i < tokens.Length; i++)
{
int token = -1;
var name = reader.GetName(columnOffset);
var type = reader.GetFieldType(columnOffset);
switch (NormalizedHash(name))
{
case 926444256U when NormalizedEquals(name, "id"):
token = type == typeof(int) ? 0 : 3; // two tokens for right-typed and type-flexible
break;
case 2369371622U when NormalizedEquals(name, "name"):
token = type == typeof(string) ? 1 : 4;
break;
case 2521315361U when NormalizedEquals(name, "productid"):
token = type == typeof(string) ? 2 : 5;
break;
}
tokens[i] = token;
columnOffset++;
}
return null;
}
public override global::DapperDemo.Product Read(global::System.Data.Common.DbDataReader reader, global::System.ReadOnlySpan<int> tokens, int columnOffset, object? state)
{
global::DapperDemo.Product result = new();
foreach (var token in tokens)
{
switch (token)
{
case 0:
result.ID = reader.GetInt32(columnOffset);
break;
case 3:
result.ID = GetValue<int>(reader, columnOffset);
break;
case 1:
result.Name = reader.GetString(columnOffset);
break;
case 4:
result.Name = GetValue<string>(reader, columnOffset);
break;
case 2:
result.ProductId = reader.GetString(columnOffset);
break;
case 5:
result.ProductId = GetValue<string>(reader, columnOffset);
break;
}
columnOffset++;
}
return result;
}
}
private sealed class CommandFactory0 : global::Dapper.CommandFactory<object?> // <anonymous type: int productId>
{
internal static readonly CommandFactory0 Instance = new();
public override void AddParameters(in global::Dapper.UnifiedCommand cmd, object? args)
{
var typed = Cast(args, static () => new { productId = default(int) }); // expected shape
var ps = cmd.Parameters;
global::System.Data.Common.DbParameter p;
p = cmd.CreateParameter();
p.ParameterName = "productId";
p.DbType = global::System.Data.DbType.Int32;
p.Direction = global::System.Data.ParameterDirection.Input;
p.Value = AsValue(typed.productId);
ps.Add(p);
}
public override void UpdateParameters(in global::Dapper.UnifiedCommand cmd, object? args)
{
var typed = Cast(args, static () => new { productId = default(int) }); // expected shape
var ps = cmd.Parameters;
ps[0].Value = AsValue(typed.productId);
}
public override bool CanPrepare => true;
}
}
}
namespace System.Runtime.CompilerServices
{
// this type is needed by the compiler to implement interceptors - it doesn't need to
// come from the runtime itself, though
[global::System.Diagnostics.Conditional("DEBUG")] // not needed post-build, so: evaporate
[global::System.AttributeUsage(global::System.AttributeTargets.Method, AllowMultiple = true)]
sealed file class InterceptsLocationAttribute : global::System.Attribute
{
public InterceptsLocationAttribute(string path, int lineNumber, int columnNumber)
{
_ = path;
_ = lineNumber;
_ = columnNumber;
}
}
}
Code and pdf at
https://ignatandrei.github.io/RSCG_Examples/v2/docs/Dapper.AOT
