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;
        }
    }