c# - Group by date-part (dd.mm.yyyy) -
i've got list of objects datetime-property. struggle in getting json-string in following form of it:
[{"date":17.08.2013,"count":8},{"day":18.08.2013,"count":10}] this
var results = in db.stalkings group new { d = a.begin.day } g select new { day = g.key.d, count = g.count() }; return json( results, jsonrequestbehavior.allowget); results in [{"day":17,"count":8},{"day":18,"count":10}]. , this
var results1 = in db.stalkings group entityfunctions.truncatetime(a.begin) g select new { day = g.key, count = g.count() }; return json( results, jsonrequestbehavior.allowget); results in [{"day":"/date(1376690400000)/","count":8},{"day":"/date(1376776800000)/","count":10}]
datetime.tostring("dd.mm.yyyy") leads linq error.
i did quick scratchup in linqpad.
i made extension class , added extension methods provided here. cannot use dumpjson() outside of linqpad, visualisation of data.
for sake of simplicity used list of datetime values. here code wil provide following output:
void main() { var foolist = new list<datetime>(); foolist.add(datetime.parse("01.01.2012")); foolist.add(datetime.parse("01.01.2012")); foolist.add(datetime.parse("01.01.2012")); foolist.add(datetime.parse("03.03.2012")); foolist.add(datetime.parse("04.04.2012")); foolist.add(datetime.parse("04.04.2012")); foolist.add(datetime.parse("04.04.2012")); foolist.add(datetime.parse("04.04.2012")); foolist.add(datetime.parse("05.05.2012")); foolist.add(datetime.parse("05.05.2012")); var result = foolist.groupby(foo => foo.date) .select(res => new { date = res.key.datetostring("dd.mm.yyyy"), count = res.count() }) ; result.dumpjson(); } public static class myextensions { public static object dumpjson(this object value, string description = null) { return getjsondumptarget(value).dump(description); } public static object dumpjson(this object value, string description, int depth) { return getjsondumptarget(value).dump(description, depth); } public static object dumpjson(this object value, string description, bool todatagrid) { return getjsondumptarget(value).dump(description, todatagrid); } private static object getjsondumptarget(object value) { object dumptarget = value; //if string contains json object, round-trip serialization format it: var stringvalue = value string; if (stringvalue != null) { if (stringvalue.trim().startswith("{")) { var obj = jsonconvert.deserializeobject(stringvalue); dumptarget = jsonconvert.serializeobject(obj, newtonsoft.json.formatting.indented); } else { dumptarget = stringvalue; } } else { dumptarget = jsonconvert.serializeobject(value, newtonsoft.json.formatting.indented); } return dumptarget; } } output:
[ { "date": "2012-01-01t00:00:00", "count": 3 }, { "date": "2012-03-03t00:00:00", "count": 1 }, { "date": "2012-04-04t00:00:00", "count": 4 }, { "date": "2012-05-05t00:00:00", "count": 2 } ] hope helps.
