代碼如下，請(qǐng)給出具體修改代碼
 public void AddCategory(string nCategoryName, int nImgId, int nBelongToId, int nShopId, int nSortId)
??? {
??????? int CategoryId = 0;
??????? string cmdText = "Select top 1 CategoryId from ProductCategory where CategoryName='' ROWLOCK";
??????? SqlConnection conn = new SqlConnection(Connection.ConnString);
??????? SqlCommand cmd = new SqlCommand(cmdText, conn);
??????? conn.Open();
??????? SqlTransaction tr = conn.BeginTransaction();
??????? cmd.Transaction = tr;
??????? try
??????? {
??????????? SqlDataReader dr = cmd.ExecuteReader();
??????????? if (dr.Read())
??????????? {
??????????????? CategoryId = Int32.Parse(dr["CategoryId"].ToString());
??????????? }
??????????? dr.Close();
??????????? if (CategoryId == 0)
??????????? {
??????????????? cmd.CommandText = "INSERT ProductCategory(CategoryName,ImgId,BelongToId,ShopId,SortId) VALUES('" + nCategoryName + "','" + nImgId + "','" + nBelongToId + "','" + nShopId + "','" + nSortId + "')";
??????????????? cmd.ExecuteNonQuery();
??????????? }
??????????? else
??????????? {
??????????????? cmd.CommandText = "Update ProductCategory Set CategoryName='" + nCategoryName + "',ImgId='" + nImgId + "',BelongToId='" + nBelongToId + "',SortId='" + nSortId + "',ShopId='" + nShopId + "' Where CategoryId=" + CategoryId;
??????????????? cmd.ExecuteNonQuery();
??????????? }
??????????? tr.Commit();
??????? }
??????? catch
??????? {
??????????? tr.Rollback();
??????? }
??????? finally { conn.Close(); }
??? }

你這樣在并發(fā)多的時(shí)候很可能造成沖突的，直接用：
cmd.CommandText = @"Update ProductCategory set xxx where xxx
if @@ROWCOUNT = 0 
insert into ProductCategory  xxx";這樣在一個(gè)sql里完成更新和插入，只用一次數(shù)據(jù)庫(kù)連接，效率提高了，并發(fā)可能也減小了

是sql，SqlServer支持同時(shí)執(zhí)行多個(gè)sql的
后面直接cmd.ExecuteNonQuery();

轉(zhuǎn)載于:https://www.cnblogs.com/zxktxj/archive/2012/10/24/2737933.html

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