public static void Main(string[] args)
{
var schema = Convention.CreateSchema <Foo>(s => s.PluralizeTableNames = true, s =>
{
s.Columns.Mapping.Add(
"AttributeCount",
Mapper
.Map("AttributeCount")
.ToColumnName("attribute_count")
.OnSelect(_ => $@"(SELECT count(*) FROM jsonb_object_keys({ s.Columns.Mapping[nameof(Foo.Attributes)].ColumnName })) as attribute_count")
.CreateMapping());
s.Columns.Mapping[nameof(Foo.SequenceNumber)]
.OnInsert = e => $@"nextval(seq_{((Dictionary<string, object>)e)[nameof(Foo.TemplateKey)]})";
s.DefaultOrderBy = (propertyName: "AttributeCount", direction: OrderDirection.Descending);
});