C# Driver- LINQ - Aggragate - Contains in Int[] -


mongo driver version: 2.2.4.26

i have following query performs aggregations. if remove contains predicate clause, query executes successfully.

i reduce , perform aggregation on server before realizing data client memory. issue encountering when use contains in clause, following exception:

$project or $group not support sum({document}{forecastquantity}).

i prefer stay in linq implementation vs. native if possible:

public class forecast {     public int markdowngroupid { get; set; }     public list<forecastdata> forecastarray { get; set; } ... }  public class forecastdata {     public int markdownnumber { get; set; }     public double forecastquantity { get; set; } ... }  public class flat {     public int markdowngroupid { get; set; }     public int markdownnumber { get; set; }     public double salesquantity { get; set; }  ... }  public class flatprojection {     public int markdowngroupid { get; set; }     public int markdownnumber { get; set; }     public double salesquantity { get; set; }  ... }  int[] groupids = new int[]{ 1,2,3 }; var forecastproductday = _mdb.getcollection<forecast>(collectionname);          var forecastproductprojections = forecastproductday             .asqueryable()             .where(x => groupids.contains(x.markdowngroupid))             .selectmany(x => x.forecastarray, (x, fa) => new flat                     {                 markdowngroupid = x.markdowngroupid,                 markdownnumber = fa.markdownnumber,                 forecastquantity = fa.forecastquantity,                 ...             })             .groupby(key => new {key.markdowngroupid, key.markdownnumber})             .select(g => new flatprojection             {                 markdowngroupid = g.key.markdowngroupid,                 markdownnumber = g.key.markdownnumber,                 salesquantity = g.sum(y => y.forecastquantity),                 ...             })             .orderby(x => x.markdowngroupid)             .thenby(x => x.markdownnumber)             .tolist();

since driver not contains() or any(). had build expression dynamically using predicatebuilder.

public static class predicatebuilder {     public static expression<func<t, bool>> true<t>() { return f => true; }     public static expression<func<t, bool>> false<t>() { return f => false; }      public static expression<func<t, bool>> or<t>(this expression<func<t, bool>> expr1,                                                         expression<func<t, bool>> expr2)     {         var invokedexpr = expression.invoke(expr2, expr1.parameters.cast<expression>());         return expression.lambda<func<t, bool>>               (expression.orelse(expr1.body, invokedexpr), expr1.parameters);     }      public static expression<func<t, bool>> and<t>(this expression<func<t, bool>> expr1,                                                          expression<func<t, bool>> expr2)     {         var invokedexpr = expression.invoke(expr2, expr1.parameters.cast<expression>());         return expression.lambda<func<t, bool>>               (expression.andalso(expr1.body, invokedexpr), expr1.parameters);     } }

list ints = new list() {1,2,3};

        var predicate = predicatebuilder.false<forecast>();         foreach (var in ints)         {             predicate = predicate.or(x => x.markdowngroupid == i);         }

var forecastproductday = _mdb.getcollection(collectionname);

    var forecastproductprojections = forecastproductday         .asqueryable()         .where(predicate.compile())         .selectmany(x => x.forecastarray, (x, fa) => new flat                 {             markdowngroupid = x.markdowngroupid,             markdownnumber = fa.markdownnumber,             forecastquantity = fa.forecastquantity,             ...         })         .groupby(key => new {key.markdowngroupid, key.markdownnumber})         .select(g => new flatprojection         {             markdowngroupid = g.key.markdowngroupid,             markdownnumber = g.key.markdownnumber,             salesquantity = g.sum(y => y.forecastquantity),             ...         })         .orderby(x => x.markdowngroupid)         .thenby(x => x.markdownnumber)         .tolist();

Comments

Post a Comment

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -

here tables: create table customer ( cid int primary key, name varchar(32) ) create table ord ( oid int primary key, cid int foreign key references customer, address varchar(20) ) here's linq-to-sql statement: var aaa = c in db.customer select new { c, o = c.ord.tolist() }; and here's inexplicable query generated linq-to-sql: select [t0].[cid] [cid], [t0].[name] [name], [t1].[oid] [oid], [t1].[cid] [cid2], [t1].[address] [address], (select count(*) [dbo].[ord] [t2] [t2].[cid] = [t0].[cid]) [value] [dbo].[customer] [t0] left outer join [dbo].[ord] [t1] on [t1].[cid] = [t0].[cid] order [t0].[cid], [t1].[oid] i want understand how rid of count(*) part. it's entirely uncalled for! linq needs count(*) in order determine number of entries returned o = c.ord.tolist() .
Read more