Advanced customization

Type mapping

public readonly record struct PositionalValue<T>(T Value);

TypeParsingInfo.AddOrSet(typeof(PositionalValue<>), CtorTypeInfo.Instance);

static readonly QueryCommand CountAlbums = new("SELECT COUNT(*) FROM albums");
PositionalValue<int> count = CountAlbums.Query<PositionalValue<int>>(cnn);

Type registration

Mapping slot rules

[AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.Field)]
sealed class DbPrefixAttribute : Attribute, INameComparerMaker
{
    public INameComparer MakeComparer(Type type, ref INameComparer current, object[] attributes, object? member)
        => new NameComparer("db_" + current.GetDefaultName());
}

public record Album([DbPrefix] int Id, string Title);

Mapping slot rules

Multi-row mapping

ConstructorInfo seed = typeof(HashSet<>).GetConstructor(Type.EmptyTypes)
    ?? throw new InvalidOperationException("HashSet constructor was not found.");
MethodInfo add = typeof(HashSet<>).GetMethod(nameof(HashSet<int>.Add))
    ?? throw new InvalidOperationException("HashSet.Add was not found.");

TypeParsingInfo.AddOrSet(typeof(HashSet<>), new MultiRowTypeParsingInfo(seed, add, null));

public record Tag(int Id, string Name) : IDbReadable;

static readonly QueryCommand GetTags = new("SELECT TagId AS Id, Name FROM tags ORDER BY TagId");
HashSet<Tag> tags = GetTags.Query<HashSet<Tag>>(cnn);

Custom multi-row mapping

Complete result parser

Complete result parser example

Other extension points

Parameter source rules

Parameter binding

Method caller

Custom conditional SQL

Cache control