Queryable.Union 方法实现json格式的字符串合并

1.在数据库中以json字符串格式保存，如：[{"name":"张三","time":"8.592","area":"27.27033","conc":"4.12136"},{"name":"李四","time":"9.100","area":"56.21229","conc":"4.57692"}]

2.添加新内容后合并不相同的数据。如果name相同，以最新的数据替换原来的数据。

如：数据库中原保存的数据是[{"name":"张三","time":"8.592","area":"27.27033","conc":"4.12136"},{"name":"李四","time":"9.100","area":"56.21229","conc":"4.57692"}]

新加的数据为[{"name":"张三","time":"12","area":"27.70533","conc":"4.12136"},{"name":"王五","time":"4","area":"77","conc":"8.788"}]

则替换后的数据为[{"name":"张三","time":"12","area":"27.70533","conc":"4.12136"},{"name":"王五","time":"4","area":"77","conc":"8.788"},{"name":"李四","time":"9.100","area":"56.21229","conc":"4.57692"}]

代码如下：

         public void InsertOrUpdateOnlyItem(List<tblLims_Ana_LE_Import_Common> listLe)
         {
             var listLeInsert = new List<tblLims_Ana_LE_Import_Common>();
             var listLeUpdate = new List<tblLims_Ana_LE_Import_Common>();
             foreach (var le in listLe)
             {
                 tblLims_Ana_LE_Import_Common model = le;
                 var own = CurrentRepository.Find(a => a.fldTaskID == model.fldTaskID
                 && a.fldBizCatID == model.fldBizCatID
                 && a.fldItemCode == model.fldItemCode
                 && a.fldNumber == model.fldNumber
                 && a.fldSampleCode == model.fldSampleCode);
                 if (own != null)
                 {
                     var ser = new JavaScriptSerializer();

                     var listown = ser.Deserialize<List<Dictionary<string, string>>>(own.fldImportData);  //原数据
                     var listmodel = ser.Deserialize<List<Dictionary<string, string>>>(model.fldImportData); //新数据
                     IEqualityComparer<Dictionary<string, string>> ec = new EntityComparer();   //自定义的比较类
                     own.fldImportData = ser.Serialize(listmodel.Union(listown, ec));  //合并数据

                     listLeUpdate.Add(own);
                 }
                 else
                 {
                     listLeInsert.Add(model);
                 }
             }
             CurrentRepository.UpdateAll(listLeUpdate);
             CurrentRepository.InsertAll(listLeInsert);
             CurrentRepository.Save();
         }

tblLims_Ana_LE_Import_Common 为数据库中存数据的表

Union() 方法中用到的自定义比较类:

     /// <summary>
     /// 自定义比较类
     /// </summary>
     public class EntityComparer : IEqualityComparer<Dictionary<string, string>>
     {
         public bool Equals(Dictionary<string, string> x, Dictionary<string, string> y)
         {
             if (ReferenceEquals(x, y)) return true;

             if (ReferenceEquals(x, null) || ReferenceEquals(y, null))
                 return false;

             return x["name"] == y["name"];  //如果名称相同就不追加
         }

         public int GetHashCode(Dictionary<string, string> obj)
         {
             if (ReferenceEquals(obj, null)) return ;
             int hashName = obj["name"] == null ?  : obj["name"].GetHashCode();
             int hashCode = obj["name"] == null ?  : obj["name"].GetHashCode();
             return hashName ^ hashCode;
         }
     }