I'm trying to query one to many on dapper but for some reason I only get 1 value back from my joined table even though I should be getting multiple as from my query
Can someone tell me what I did wrong?
I tried doing what was mentioned in the following post answer Mapping one to many with Dapper
My code:
public class MonsterDatabase
{
public int Id { get; set; }
public int MonsterId { get; set; }
public string Name { get; set; }
public List<MonsterLocationDatabase> Location { get; set; }
}
public class MonsterLocationDatabase
{
public int Id { get; set; }
public int FkMonsterId { get; set; }
public string Map { get; set; }
public int Frequency { get; set; }
public string MapImage { get; set; }
public DateTime? DeathTime { get; set; }
public DateTime? RespawnTime { get; set; }
}
public static MonsterDatabase GetMonster(Monster monster)
{
using (var connection = new SqlConnection(config["appsettings:RagnaDatabase"]))
{
var Monster = connection.Query<MonsterDatabase, MonsterLocationDatabase, MonsterDatabase>(
"select top 1 Monster.*, SplitMonster = '', MonsterLocation.*" +
" from Monster" +
" join MonsterLocation" +
" on Monster.Id = MonsterLocation.FkMonsterId",
(Monster, Location) =>
{
Monster.Location = new List<MonsterLocationDatabase>();
Monster.Location.Add(Location);
return Monster;
}, splitOn: "SplitMonster"
).FirstOrDefault();
return Monster;
}
}
I was able to fix the issue by following the one to many dapper documentation on
https://dapper-tutorial.net/result-multi-mapping
public static MonsterDatabase GetMonster()
{
using (var connection = new SqlConnection(config["appsettings:RagnaDatabase"]))
{
var monsterDictionary = new Dictionary<int, MonsterDatabase>();
var Monster = connection.Query<MonsterDatabase, MonsterLocationDatabase, MonsterDatabase>(
"select top 10 Monster.*, SplitMonster = '', MonsterLocation.*" +
" from Monster" +
" left join MonsterLocation" +
" on Monster.Id = MonsterLocation.FkMonsterId",
(Monster, Location) =>
{
MonsterDatabase monsterEntry;
if(!monsterDictionary.TryGetValue(Monster.Id, out monsterEntry))
{
monsterEntry = Monster;
monsterEntry.Location = new List<MonsterLocationDatabase>();
monsterDictionary.Add(monsterEntry.Id, monsterEntry);
}
monsterEntry.Location.Add(Location);
return monsterEntry;
}, splitOn: "SplitMonster"
).Distinct().FirstOrDefault();
return Monster;
}
}
Related
I`m having simple method which builds IQueryable and returns it.
public IQueryable<ClassDTO> ReportByNestedProperty()
{
IQueryable<Class> query = this.dbSet;
IQueryable<ClassDTO> groupedQuery =
from opportunity in query
group new
{
ItemGroup = opportunity.OpportunityStage.Name,
EstimatedRevenue = opportunity.EstimatedRevenue,
CostOfLead = opportunity.CostOfLead
}
by new
{
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
}
into item
select new ClassDTO()
{
ItemGroup = string.IsNullOrEmpty(item.Key.Name) ? "[Not Assigned]" : item.Key.Name,
Count = item.Select(z => z.ItemGroup.Name).Count(), // int
Commission = item.Sum(z => z.EstimatedRevenue), // decimal
Cost = item.Sum(z => z.CostOfLead), // decimal?
};
return groupedQuery;
}
This is fine. The thing i need is to create method with same return type, but groupby by different prperties dynamically. So from the above code I want to have 3 dynamic parts which will be passed as params:
ItemGroup = opportunity.OpportunityStage.Name
and
by new
{
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
}
So the new method should be like this
public IQueryable<ClassDTO> ReportByNestedProperty(string firstNestedGroupByProperty, string secondNestedGroupByProperty)
{
// TODO: ExpressionTree
}
And call it like this:
ReportByNestedProperty("OpportunityStage.Name","OpportunityStage.Id")
ReportByNestedProperty("OtherNestedProperty.Name","OtherNestedProperty.Id")
ReportByNestedProperty("OpportunityStage.Name","OpportunityStage.Price")
So the main thing is to create expressions with these two selects:
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
I have tried toe create the select expressions, groupby, the creation of Anonomoys classes and the DTO Class but I just cant get it right.
EDIT:
Here are the classes involved:
public class ClassDTO
{
public ClassDTO() { }
[Key]
public string ItemGroup { get; set; }
public decimal Commission { get; set; }
public decimal? Cost { get; set; }
public int Count { get; set; }
}
Class obj is a pretty big one so i`m posting just part of it
public partial class Class
{
public Class() { }
[Key]
public Guid Id { get; set; }
public Guid? OpportunityStageId { get; set; }
[ForeignKey(nameof(OpportunityStageId))]
[InverseProperty(nameof(Entities.OpportunityStage.Class))]
public virtual OpportunityStage OpportunityStage { get; set; }
}
public partial class OpportunityStage
{
public OpportunityStage()
{
this.Classes = new HashSet<Class>();
}
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
[InverseProperty(nameof(Class.OpportunityStage))]
public virtual ICollection<TruckingCompanyOpportunity> Classes{ get; set; }
}
I have simplified your Grouping query and introduced private class IdName which should replace anonymous class usage:
class IdName
{
public int Id { get; set; }
public string Name { get; set; } = null!;
}
static Expression MakePropPath(Expression objExpression, string path)
{
return path.Split('.').Aggregate(objExpression, Expression.PropertyOrField);
}
IQueryable<ClassDTO> ReportByNestedProperty(IQueryable<Class> query, string nameProperty, string idProperty)
{
// Let compiler to do half of the work
Expression<Func<Class, string, int, IdName>> keySelectorTemplate = (opportunity, name, id) =>
new IdName { Name = name, Id = id };
var param = keySelectorTemplate.Parameters[0];
// generating expressions from prop path
var nameExpr = MakePropPath(param, nameProperty);
var idExpr = MakePropPath(param, idProperty);
var body = keySelectorTemplate.Body;
// substitute parameters
body = ReplacingExpressionVisitor.Replace(keySelectorTemplate.Parameters[1], nameExpr, body);
body = ReplacingExpressionVisitor.Replace(keySelectorTemplate.Parameters[2], idExpr, body);
var keySelectorLambda = Expression.Lambda<Func<Class, IdName>>(body, param);
// finalize query
IQueryable<ClassDTO> groupedQuery = query
.GroupBy(keySelectorLambda)
.Select(item => new ClassDTO()
{
ItemGroup = string.IsNullOrEmpty(item.Key.Name) ? "[Not Assigned]" : item.Key.Name,
Count = item.Count(x => x.Name), // int
Commission = item.Sum(x => x.EstimatedRevenue), // decimal
Cost = item.Sum(x => x.CostOfLead), // decimal?
});
return groupedQuery;
}
error message:
http://prntscr.com/qtlodf
method:
public IActionResult GroepsResultaten(int vakId, int groepId)
{
var studentenLijst = _context.Student.Join(_context.StudentGroep,
s => s.Id,
sg => sg.StudentId,
(s, sg) => new { Student = s, StudentGroep = sg })
.Where(x => x.StudentGroep.GroepId == groepId)
.Select(x => x.Student);
ViewBag.Studenten = new SelectList(studentenLijst, "Id", "Naam");
return View();
}
I've also tried this:
public IActionResult GroepsResultaten(int vakId, int groepId)
{
var studentInfo = _context.Student
.Select(s =>
new
{
s.Id,
Naam = string.IsNullOrEmpty(s.Tussenvoegsel)
? s.Voornaam + " " + s.Achternaam + " - " + s.Studentnummer
: s.Voornaam + " " + s.Tussenvoegsel + " " + s.Achternaam + " - " + s.Studentnummer,
forStudent = s.Studentnummer + "-" + s.Achternaam
});
ViewBag.Studenten = new SelectList(studentInfo, "Id", "Naam");
return View();
}
I'm a bit stuck at this. I want to return multiple input fields (I'm just testing with selectlist at the moment) for all students of group x, from there on I want to be able to grade students for the subject that's included in the view using get method. Because English isn't my first language I've included two screenshots to clarify what I mean.
clarification of what I want to achieve:
group view: http://prntscr.com/qtlrqd
wireframe of method view: http://prntscr.com/qtlswn
models:
public class Student
{
public int Id { get; set; }
[Required]
public string Voornaam { get; set; }
[Required]
public string Achternaam { get; set; }
public string Tussenvoegsel { get; set; }
public string Studentnummer { get; set; }
public List<Resultaat> Resultaten { get; set; }
public List<StudentGroep> Groepen { get; set; }
}
public class Groep
{
public int Id { get; set; }
[Required]
public string Naam { get; set; }
[Required]
public string Groepscode { get; set; }
public List<GroepVak> Vakken { get; set; }
public List<StudentGroep> Studenten { get; set; }
}
public class StudentGroep
{
public Student Student { get; set; }
public int StudentId { get; set; }
public Groep Groep { get; set; }
public int GroepId { get; set; }
}
I hope I've included enough information, I'm available on discord too if that makes it easier.
The problem is what the SelectList class returns. Because view side results that ViewBag.Studenten is null.
Also, you must make sure that the database query returns a value.
Using ViewData resulted in what I want, from here on I can hopefully figure out how to use it for posting grades for each student.
Method:
public IActionResult GroepsResultaten(int vakId, int groepId)
{
var studentenLijst = _context.Student.Join(_context.StudentGroep,
s => s.Id,
sg => sg.StudentId,
(s, sg) => new { Student = s, StudentGroep = sg })
.Where(x => x.StudentGroep.GroepId == groepId)
.Select(x => x.Student)
.ToList();
if (groepId >= 1)
{
ViewData["Studenten"] = studentenLijst.ToList();
}
//ViewBag.Studenten = new SelectList(studentenLijst, "Id", "Naam");
return View();
}
View:
#foreach (var item in ViewBag.Studenten)
{
#item.Voornaam;
<input type="number" />
}
Im trying to access and display the value of a dictionary where the dictionary has no real name but is a property of a class.
Currently I have an enum "Roles" with three elements (fighter, rogue, and sorcerer), and:
public class Adventurer
{
public int ID { get; set; }
public string Name { get; set; }
public Roles Role { get; set; }
public List<Skill> Skills { get; set; }
public override string ToString()
{
return $"{ID}" + " - " + $"{Name}" + " - " + $"{Role}";
}
}
and:
public class Skill
{
public int ID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public Dictionary<Roles, Skill> LinkedTo { get; set; }
}
and in another class I have:
private void CreateSkills()
{
Skill swordFighting = new Skill() { ID = 1, Name = "Sword fighting"};
Skill stealth = new Skill() { ID = 2, Name = "Stealth"};
Skill magic = new Skill() { ID = 3, Name = "Magic"};
swordFighting.LinkedTo = new Dictionary<Roles, Skill>
{
{ Roles.Fighter, swordFighting }
};
stealth.LinkedTo = new Dictionary<Roles, Skill>
{
{ Roles.Rogue, stealth }
};
magic.LinkedTo = new Dictionary<Roles, Skill>
{
{ Roles.Sorcerer, magic }
};
}
private void DisplaySkills(Adventurer adventurer)
{
adventurer.Skills = adventurer.Role.LinkedTo; // I WOULD LIKE SOMETHING LIKE THIS...
lstAdventurer.ItemsSource = adventurer.Skills;
}
Is there some way of accessing the values (skills) of the adventurer by knowing only the role (fighter/rogue/sorcerer)?
Best,
Dedoj
Would you mean something like this?
for known Roles like Roles.Fighter:
adventurer.Skills = adventurer.Skills
.Select(s => s.LinkedTo.ContainsKey(Roles.Fighter) ? s.LinkedTo[Roles.Fighter] : null)
.Where(s => s != null).ToList();
I'm currently working on parsing a csv file that was exported by another application. This application exported the data in a strange way. This export is from accoutning and it looks similar to this..
I'm trying to figure out a way to read the csv file, then split up the multiple 'All Accounts' values and 'Amt' Values so that M200 and 300.89 is another entry, M300 and 400.54 are another entry, and M400 and 100.00 are another entry. So after inserting this single row into the database, I should actually have 4 rows like so..
This is how I'm currently reading and inserting into the database.
List<RawData> data = new List<RawData>();
try
{
string text = File.ReadAllText(lblFileName.Text);
string[] lines = text.Split('\n');
int total = 0, reduced = 0;
foreach (string line in lines)
{
RawData temp = new RawData(line);
total++;
if (!(temp.FirstAccount.Length == 0 || temp.FirstAccount == "1ST-ACCT-NO"))
{
reduced++;
data.Add(temp);
}
}
}
catch (IOException ex)
{
Console.WriteLine("Unable to read file. " + ex.ToString());
MessageBox.Show(ex.ToString());
}
try
{
foreach (RawData rData in data)
{
tCarsInTransit cit = new tCarsInTransit
{
FIRST_ACCT_NO = rData.FirstAccount,
ACCOUNT_NO_DV = rData.AccountNoDv,
ACCT_NO = rData.AcctNo,
ACCT_NO_L = rData.AccNoL,
ACCT_NUM_DV = rData.AcctNumDv,
ACCT_PFX = rData.AcctPfx,
ACCT_PFX_PRT = rData.AcctPfxPrt,
ACCT_TYPE_DV = rData.AcctTypeDv,
ADV_NO = rData.AdvNo,
ALL_PRT_FLAG = rData.AllPrtFlag,
AMT = rData.Amt,
AMT_GLE = rData.AmtGle,
BASE_GLE = rData.BaseGle,
CNT_CAT = rData.CntCat,
COLD_PRT_FLAG = rData.ColdPrtFlag,
COST_DV = rData.CostDv,
COST_OVRD_FLAG_DV = rData.CostOvrdFlagDv,
CR_ACCT_DV = rData.CrAcctDv,
CR_ACCT_DV_GLE = rData.CrAcctDvGle,
CROSS_POSTING_FLAG = rData.CrossPostingFlag,
CROSS_POST_CAT = rData.CrossPostCat,
CTRL_NO = rData.CtrlNo,
CTRL_TYPE_DV = rData.CtrlTypeDv,
DESC_REQD_DV = rData.DescReqdDv,
DR_ACCT_DV = rData.DrAcctDv,
GL_DIST_ACCT_DV = rData.GLDistAcctDv,
GL_DIST_DV = rData.GLDistDv,
GRP_NO_DV = rData.GrpNoDv,
ID_PORT_DATE_TIME_FMT_CAT = rData.IdPortDateTimeFmtCat,
INACTIVITY_DV = rData.InactivityDv,
JOIN_COL = rData.JoinCol,
JRNL_DATE = rData.JrnlDate,
JRNL_PFX = rData.JrnlPfx
};
tCIT.tCarsInTransits.Add(cit);
tCIT.SaveChanges();
lblMessage.ForeColor = System.Drawing.Color.Green;
lblMessage.Text = "Finished uploading. ";
}
}
catch (DbEntityValidationException ex)
{
foreach (var eve in ex.EntityValidationErrors)
{
Console.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
eve.Entry.Entity.GetType().Name, eve.Entry.State);
foreach (var ve in eve.ValidationErrors)
{
Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
ve.PropertyName, ve.ErrorMessage);
}
}
throw;
}
I am not sure how to accomplish this. The above currently inserts the csv file into Sql Server the exact way the csv file was exported. Any ideas would greatly be appreciated! Thanks!
EDIT: Here is the RawData class.
class RawData
{
public string FirstAccount { get; set; }
public string AccountNoDv { get; set; }
public string AcctNo { get; set; }
public string AccNoL { get; set; }
public string AcctNumDv { get; set; }
public string AcctPfx { get; set; }
public string AcctPfxPrt { get; set; }
public string AcctTypeDv { get; set; }
public string AdvNo { get; set; }
public string AllPrtFlag { get; set; }
public string Amt { get; set; }
public string AmtGle { get; set; }
public string BaseGle { get; set; }
public string CntCat { get; set; }
public string ColdPrtFlag { get; set; }
public string CostDv { get; set; }
public string CostOvrdFlagDv { get; set; }
public string CrAcctDv { get; set; }
public string CrAcctDvGle { get; set; }
public string CrossPostingFlag { get; set; }
public string CrossPostCat { get; set; }
public string CtrlNo { get; set; }
public string CtrlTypeDv { get; set; }
public string DescReqdDv { get; set; }
public string DrAcctDv { get; set; }
public string GLDistAcctDv { get; set; }
public string GLDistDv { get; set; }
public string GrpNoDv { get; set; }
public string IdPortDateTimeFmtCat { get; set; }
public string InactivityDv { get; set; }
public string JoinCol { get; set; }
public string JrnlDate { get; set; }
public string JrnlPfx { get; set; }
public RawData(string csvString)
{
string[] citData = csvString.Replace(", ", "").Replace(".,", ".").Split(',');
try
{
FirstAccount = citData[0];
AccountNoDv = citData[1];
AcctNo = citData[2];
AccNoL = citData[3];
AcctNumDv = citData[4];
AcctPfx = citData[5];
AcctPfxPrt = citData[6];
AcctTypeDv = citData[7];
AdvNo = citData[8];
AllPrtFlag = citData[9];
Amt = citData[10];
AmtGle = citData[11];
BaseGle = citData[12];
CntCat = citData[13];
ColdPrtFlag = citData[14];
CostDv = citData[15];
CostOvrdFlagDv = citData[16];
CrAcctDv = citData[17];
CrAcctDvGle = citData[18];
CrossPostingFlag = citData[19];
CrossPostCat = citData[20];
CtrlNo = citData[21];
CtrlTypeDv = citData[22];
DescReqdDv = citData[23];
DrAcctDv = citData[24];
GLDistAcctDv = citData[25];
GLDistDv = citData[26];
GrpNoDv = citData[27];
IdPortDateTimeFmtCat = citData[28];
InactivityDv = citData[29];
JoinCol = citData[30];
JrnlDate = citData[31];
JrnlPfx = citData[32];
}
catch (Exception ex)
{
Console.WriteLine("Something went wrong. " + ex.ToString());
}
}
}
EDIT 2: AllAccounts in the images is acutally 'AccountNoDv' and there are actually many different fields that have multiples like 'AccountNoDv'(AllAccounts) but we might be removing those as this is not a final export. As of right now the two fields I'm worried most about are AccountNoDv and Amt.
Try something like this:
foreach (string line in lines)
{
RawData temp = new RawData(line);
var AllAccounts = temp.AccountNoDv.split(' ');
var Amts = temp.Amt.split(' ');
if (AllAccounts.Length() == Amts.Length() && Amts.Length() > 1) {
// We have multiple values!
reduced++;
for (int i = 0; i < AllAccounts.Length(); i++) {
RawData temp2 = RawDataCopy(temp); // Copy the RawData object
temp2.AccountNoDv = AllAccounts[i];
temp2.Amt = Amts[i];
total++;
data.Add(temp2);
}
}
else {
total++;
if (!(temp.FirstAccount.Length == 0 || temp.FirstAccount == "1ST-ACCT-NO"))
{
reduced++;
data.Add(temp);
}
}
}
And:
private RawData RawDataCopy(RawData copyfrom) {
// Write a function here that returns an exact copy from the one provided
// You might have to create a parameterless constructor for RawData
RawData RawDataCopy = new RawData();
RawDataCopy.FirstAccount = copyfrom.FirstAccount;
RawDataCopy.AccountNoDv = copyfrom.AccountNoDv;
RawDataCopy.AcctNo = copyfrom.AcctNo;
// . . . . . . . .
RawDataCopy.JrnlPfx = copyfrom.JrnlPfx;
return RawDataCopy;
}
Then also add a parameterless constructor to your RawData class:
public RawData()
{
}
Perhaps it would be sexier to implement the ICloneable interface and call the Clone() function instead of the RawDataCopy function, but it gets the idea across.
In Linq you can use SelectMany to increase the number of elements in a list. Here is a rough example of how this could be done. I make the assumption that the number of sub elements in AllAccounts and Amt is the same. A more robust solution would check for these issues.
So after you have loaded your data list:
var expandedData =
data.SelectMany(item =>
// split amount (will just return one item if no spaces)
item.Amt.Split(" ".ToCharArray())
// join this to the split of all accounts
.Zip(item.AllAccounts.Split(" ".ToCharArray()),
// return the joined item as a new anon object
(a,b) => new { amt=a, all=b }),
// take the original list item and the anon object and return our new item
(full,pair) => { full.Amt = pair.amt; full.AllAccounts = pair.all; return full; }));
You will now have a list of your data items with the multiple items expanded into the list.
I don't have test data to test so I might have some minor typos -- but I put in lots of comments to make the Linq as clear as possible.
Here is is simple example I wrote in LinqPad for myself to make sure I understood how SelectMany worked:
string [] list = { "a b c d","e","f g" };
var result = list.SelectMany((e) =>
e.Split(" ".ToCharArray()),
(o,item) => new { org = o, item = item}).Dump();
Given this document class:
public class Tea
{
public String Id { get; set; }
public String Name { get; set; }
public TeaType Type { get; set; }
public Double WaterTemp { get; set; }
public Int32 SleepTime { get; set; }
}
public enum TeaType
{
Black,
Green,
Yellow,
Oolong
}
I store a new Tea with the following code:
using (var ds = new DocumentStore { Url = "http://localhost:8080/" }.Initialize())
using (var session = ds.OpenSession("RavenDBFirstSteps"))
{
Tea tea = new Tea() { Name = "Earl Grey", Type = TeaType.Black, WaterTemp = 99d, SleepTime = 3 };
session.Store(tea);
session.SaveChanges();
Console.WriteLine(tea.Id);
}
The tea will be successfully saved, but when I try to query all black teas with linq, I am getting no results:
using (var ds = new DocumentStore { Url = "http://localhost:8080/" }.Initialize())
using (var session = ds.OpenSession("RavenDBFirstSteps"))
{
var dbTeas = from teas in session.Query<Tea>()
where teas.Type == TeaType.Black
select teas;
foreach (var dbTea in dbTeas)
{
Console.WriteLine(dbTea.Id + ": " + dbTea.Name);
}
}
I also tried to save the Enum as Integer with the following command:
ds.Conventions.SaveEnumsAsIntegers = true;
But, the result is the same. All works when I use the Name or the WaterTemp. Does RavenDB supports Enums in this way or I am totally wrong?
It seemed that I got the answer. It is always not recommended to use properties with a name like Type, which can be a reserved keyword.
I renamed Type and everything works, so the answer is:
public class Tea
{
public String Id { get; set; }
public String Name { get; set; }
public TeaType TeaType { get; set; }
public Double WaterTemp { get; set; }
public Int32 SleepTime { get; set; }
}