SQL string access

const string sql = "SELECT AlbumId AS Id, Title FROM albums WHERE ArtistId = @artistId";

List<Album> albums = cnn.Query<List<Album>>(sql, new { artistId = 7 });

The first access for an exact SQL string creates its QueryCommand. Later accesses with that exact string reuse the cached command.

Access the command

QueryCommand command = ConnectionQueryExtensions.GetOrCreateCommand(sql);
List<Album> albums = command.Query<List<Album>>(cnn, new { artistId = 7 });

The string and direct command forms now access the same cached command instance.

Exact cache key

QueryCommand first = ConnectionQueryExtensions.GetOrCreateCommand("SELECT AlbumId FROM albums");
QueryCommand second = ConnectionQueryExtensions.GetOrCreateCommand("select AlbumId FROM albums");

Console.WriteLine(ReferenceEquals(first, second));
// False. The SQL text is not the same exact string value.

Whitespace differences also produce different keys.

Remove one cached command

const string sql = "SELECT AlbumId AS Id, Title FROM albums";

ConnectionQueryExtensions.CommandCache.TryRemove(sql, out QueryCommand? cached);

Removing the cache entry does not dispose the removed QueryCommand.

Command parser caches