Transaction (Process ID) was deadlocked errors

I am having an issue with my code and the numerous SQL calls that it makes with deadlocks. I pasted the code into PasteBin here: https://pastebin.com/p1YDkKsB. Can someone help me out here? It happens most often in the CheckClanActivity task here:

using(SqlCommand cmd = new SqlCommand(string.Format("select * from ClanMembers where MembershipId={0} and IsActive = 1", entry.Player.DestinyUserInfo.MembershipId), conn))


, but it also happens all over the place.

Edit:
Okay, the involved SQL statements are as follows:

if not exists(select * from ClanMembers where MembershipId={0}) begin insert into ClanMembers(ID, MembershipId, BattleNetId, ClanId, DateLastPlayed, IsActive, LastUpdated) select ISNULL(MAX(ID) + 1, 0),{0},'{1}',{2},'{3}', 1, GETDATE() from ClanMembers end else begin update ClanMembers set DateLastPlayed='{3}', LastUpdated=GETDATE() where MembershipId={0} end

if not exists(select * from ClanMemberCharacters where CharacterId={1}) begin insert into ClanMemberCharacters(ID,MembershipId,CharacterId) select ISNULL(MAX(ID)+1,0),{0},{1} from ClanMemberCharacters end

select c.* from ClanMemberCharacters c join ClanMembers m on m.MembershipId = c.MembershipId where m.IsActive = 1 ORDER BY m.MembershipId desc

select * from ActivityHistory where InstanceId = {0}

if not exists(select * from ActivityHistory where InstanceId = {0}) begin insert into ActivityHistory(InstanceId,MembershipId,CharacterId,GameMode,ActivityDate,ReferenceId,DirectorActivityHash,IsPrivate,ClanActivity,ClanActivityCount) values( {0},{1},{2},'{3}','{4}',{5},{6},{7},{8},{9} ) END

select * from ClanMembers where IsActive = 1

Select * from ClanMembers where IsActive = 0

update ClanMembers set IsActive = 1 where MembershipId = {0}

select * from ClanMembers where MembershipId={0} and IsActive = 1


1 Answer
1

I suspect the problem is the nesting of SqlConnections with the same connection string one within the other. Suggestions:

SqlConnection

using

if (conn.State == ConnectionState.Closed) { conn.Open(); }

conn.Open();

SqlConnection

conn.Close()

using

SqlDataAdapter

using

throw;

ex.ToString()

ex.Message

string.Format

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.