I have been using dapper for one of my projects and in one case I wanted to return a tuple of primitive data types. (only a single row) Since I used dapper, I really would like to use dapper for this case also. I checked these links but couldn't find a solution
Can I map a result to Tuple in Dapper?
Dapper multiple objects from one row
Using Dapper to map more than 5 types
This is what my code looks like,
Using(_dbTransaction = _dbConnection.BeginTransaction()){
var command = new CommandDefinition(
"SELECT ID1,ID2 " +
"FROM table " +
"WHERE ID0 = @ID",
new {ID = 34},_dbTransaction); //34 is just a number
var dataSet = _dbConnection.QueryFirst<Tuple<uint, decimal>>(command);
//assign the retrieved values to properties of orderItem (orderItem is a passed object as a parameter)
orderItem.Id = dataSet.item1;
orderItem.ContainerPrice = dataSet.item2;
}
but this would generate an exception
{"A parameterless default constructor or one matching signature (System.UInt32 Id, System.Decimal ContainerPrice) is required for System.Tuple`2[[System.UInt32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Decimal, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] materialization"}
It would be a great help if can suggest a method or point out where I went wrong
If you want to use a Tuple, you can try this:
[Test]
public void TupleTest()
{
var result = _connection.Query<int, decimal, Tuple<int, decimal>>
("select 1 as Id, 12.99 as ContainerPrice", Tuple.Create, splitOn: "*")
.FirstOrDefault();
Assert.That(result.Item1, Is.EqualTo(1));
Assert.That(result.Item2, Is.EqualTo(12.99));
}
You can also avoid Tuples, and use a dynamic:
[Test]
public void DynamicTest()
{
var result = _connection.Query<dynamic>
("select 1 as Id, 12.99 as ContainerPrice")
.FirstOrDefault();
Assert.That(result.Id, Is.EqualTo(1));
Assert.That(result.ContainerPrice, Is.EqualTo(12.99));
}
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