public static IEnumerable <Commit <byte[]> > Execute(DocumentTransaction tx, ReadEventsByCommitIds command)
{
if (!command.Ids.Any())
{
return(Enumerable.Empty <Commit <byte[]> >());
}
var parameters = new DynamicParameters();
foreach (var param in command.Ids.Select((value, i) => (name: $"@p{i}", value: value)))
{
parameters.Add(param.name, param.value);
}
var sql = $@"
SELECT Position, EventId, CommitId, StreamId, SequenceNumber, Name, Generation, Metadata, Data
FROM {tx.Store.Database.FormatTableNameAndEscape(command.Table.Name)}
WHERE CommitId IN ({string.Join(", ", parameters.ParameterNames.Select(x => $"@{x}"))})
ORDER BY Position";
var commits = new[] { Commit.Empty <byte[]>() }.Concat(
from row in tx.SqlConnection.Query <Row>(sql, parameters, tx.SqlTransaction)
group row by row.CommitId
into grouping
let last = grouping.Last()
select Commit.Create(grouping.Key, last.Generation, last.Position, grouping.Select(Row.ToEvent).ToList())
).ToList();
return
(from id in command.Ids
join commit in commits on id equals commit.Id into cs
from commit in cs.DefaultIfEmpty()
select commit);
}
