public async Task AddOpTag(List <RecruitJson> recruits) { try { List <OperatorTag> ot = new List <OperatorTag>(); foreach (RecruitJson r in recruits) { Operator op = await applicationDb.Operators .Where(o => o.Name.ToLower().Equals(r.Name.ToLower())) .Select(o => new Operator() { OperatorId = o.OperatorId }) .SingleOrDefaultAsync(); if (op != null) { foreach (string e in r.TagList) { int tagId = ArknightUtil.GetTagId(e); if (tagId != 0) { ot.Add(new OperatorTag(op.OperatorId, tagId)); } } } } await applicationDb.AddRangeAsync(ot); await applicationDb.SaveChangesAsync(); } catch (Exception e) { throw e; } }