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