Dapper mapping throws invalid cast
Two tables:
+-Person-+ +--Rank--+
| Id | | Id |
| FName | | Name |
| LName | +--------+
| Rank |
+--------+
The object model looks the exact same except Rank in Person is of type RankModel instead of int.
I do a simple inner join on them:
string sql = "SELECT pe.Id, pe.LName, pe.FName, pe.Rank, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
Then I use Dapper to map:
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}).ToList();
But I get an exception:
InvalidCastException: Invalid cast from 'System.Int16' to 'MainDB.Models.RankModel'.
Clearly it's trying to cast an int to a RankModel, but I can't figure out why -- it should be splitting the return into two objects and then attaching the RankModel object into the Rank property of the PersonModel object. This is driving me crazy, I've spent 3 hours on this and can't figure out what's going on.
c# sql wpf dapper
asked Nov 18 '18 at 1:34
linus72982
7321022
add a comment |
Two tables:
+-Person-+ +--Rank--+
| Id | | Id |
| FName | | Name |
| LName | +--------+
| Rank |
+--------+
The object model looks the exact same except Rank in Person is of type RankModel instead of int.
I do a simple inner join on them:
string sql = "SELECT pe.Id, pe.LName, pe.FName, pe.Rank, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
Then I use Dapper to map:
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}).ToList();
But I get an exception:
InvalidCastException: Invalid cast from 'System.Int16' to 'MainDB.Models.RankModel'.
Clearly it's trying to cast an int to a RankModel, but I can't figure out why -- it should be splitting the return into two objects and then attaching the RankModel object into the Rank property of the PersonModel object. This is driving me crazy, I've spent 3 hours on this and can't figure out what's going on.
c# sql wpf dapper
asked Nov 18 '18 at 1:34
linus72982
7321022
add a comment |
Two tables:
+-Person-+ +--Rank--+
| Id | | Id |
| FName | | Name |
| LName | +--------+
| Rank |
+--------+
The object model looks the exact same except Rank in Person is of type RankModel instead of int.
I do a simple inner join on them:
string sql = "SELECT pe.Id, pe.LName, pe.FName, pe.Rank, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
Then I use Dapper to map:
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}).ToList();
But I get an exception:
InvalidCastException: Invalid cast from 'System.Int16' to 'MainDB.Models.RankModel'.
Clearly it's trying to cast an int to a RankModel, but I can't figure out why -- it should be splitting the return into two objects and then attaching the RankModel object into the Rank property of the PersonModel object. This is driving me crazy, I've spent 3 hours on this and can't figure out what's going on.
c# sql wpf dapper
asked Nov 18 '18 at 1:34
linus72982
7321022
Two tables:
+-Person-+ +--Rank--+
| Id | | Id |
| FName | | Name |
| LName | +--------+
| Rank |
+--------+
The object model looks the exact same except Rank in Person is of type RankModel instead of int.
I do a simple inner join on them:
string sql = "SELECT pe.Id, pe.LName, pe.FName, pe.Rank, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
Then I use Dapper to map:
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}).ToList();
But I get an exception:
InvalidCastException: Invalid cast from 'System.Int16' to 'MainDB.Models.RankModel'.
Clearly it's trying to cast an int to a RankModel, but I can't figure out why -- it should be splitting the return into two objects and then attaching the RankModel object into the Rank property of the PersonModel object. This is driving me crazy, I've spent 3 hours on this and can't figure out what's going on.
c# sql wpf dapper
c# sql wpf dapper
asked Nov 18 '18 at 1:34
linus72982
7321022
asked Nov 18 '18 at 1:34
linus72982
7321022
asked Nov 18 '18 at 1:34
linus72982
7321022
asked Nov 18 '18 at 1:34
linus72982
7321022
asked Nov 18 '18 at 1:34
linus72982
7321022
7321022
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You need to add 'splitOn' param in query statement in order to split them into Person, Rank model objects.
Also your sql needs to be refactored as below
string sql = "SELECT pe.Id, pe.LName, pe.FName, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
And your statement should be
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}, splitOn:"Id,Id").ToList();
answered Nov 18 '18 at 2:13
RajN
3,60521021
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You need to add 'splitOn' param in query statement in order to split them into Person, Rank model objects.
Also your sql needs to be refactored as below
string sql = "SELECT pe.Id, pe.LName, pe.FName, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
And your statement should be
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}, splitOn:"Id,Id").ToList();
answered Nov 18 '18 at 2:13
RajN
3,60521021
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
add a comment |
You need to add 'splitOn' param in query statement in order to split them into Person, Rank model objects.
Also your sql needs to be refactored as below
string sql = "SELECT pe.Id, pe.LName, pe.FName, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
And your statement should be
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}, splitOn:"Id,Id").ToList();
answered Nov 18 '18 at 2:13
RajN
3,60521021
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
add a comment |
You need to add 'splitOn' param in query statement in order to split them into Person, Rank model objects.
Also your sql needs to be refactored as below
string sql = "SELECT pe.Id, pe.LName, pe.FName, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
And your statement should be
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}, splitOn:"Id,Id").ToList();
answered Nov 18 '18 at 2:13
RajN
3,60521021
You need to add 'splitOn' param in query statement in order to split them into Person, Rank model objects.
Also your sql needs to be refactored as below
string sql = "SELECT pe.Id, pe.LName, pe.FName, ra.Id, ra.Name" +
"FROM Person pe INNER JOIN Rank ra ON ra.Id = pe.Rank";
And your statement should be
return connection.Query<PersonModel, RankModel, PersonModel>(sql, (per, rank) =>
{
per.Rank = rank;
return per;
}, splitOn:"Id,Id").ToList();
answered Nov 18 '18 at 2:13
RajN
3,60521021
answered Nov 18 '18 at 2:13
RajN
3,60521021
answered Nov 18 '18 at 2:13
RajN
3,60521021
answered Nov 18 '18 at 2:13
RajN
3,60521021
3,60521021
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
add a comment |
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
Well, that did it, I'm not sure why I was querying the extra Rank in person. As for splitOn, I thought the default was Id, anyway?
– linus72982
Nov 18 '18 at 2:17
add a comment |
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