此存储过程如何控制并发

[zyk168]

ALTER procedure [dbo].[vote_ins_yog]
(
@PlayerId varchar(10),
@TickNumber int,
@voteNum varchar(10),
@tell varchar(15),
@voteTick int,
@createTimee datetime,
@err int output
)
as

begin transaction

	if exists(select * from Vote_Product   where PlayerId=@PlayerId)
	begin
	INSERT INTO [vote_yyTick](
	[voteNum],[tel],[voteTick],[createTime]
	)VALUES(
	@voteNum,@tell,@voteTick,@createTimee
	)
	if @@error <> 0 
	begin
		rollback transaction--发生错误则回滚事务，无条件退出
			set @err=1
		return
    end
    UPDATE [Vote_Product]  SET 
	[TickNumber] =[TickNumber]+@TickNumber 
	WHERE PlayerId=@PlayerId 
	 if @@error <> 0 
	begin
		rollback transaction--发生错误则回滚事务，无条件退出
			set @err=1
		return
    end
		
	 commit transaction 
		set @err=0
	end
	else
	begin
		rollback transaction--发生错误则回滚事务，无条件退出
			set @err=1
		return
	end