Queryable.Union 方法实现json格式的字符串合并的具体实例

  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:

  

复制代码 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:

  

复制代码 代码如下:

  /// <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 0;

  int hashName = obj["name"] == null ? 0 : obj["name"].GetHashCode();

  int hashCode = obj["name"] == null ? 0 : obj["name"].GetHashCode();

  return hashName ^ hashCode;

  }

  }