Is there a way to access the columns in a Dapper FastExpando via string or index?

11,661

Solution 1

Sure, it is actually way easier than that:

var sql = "select 1 A, 'two' B";
var row = (IDictionary<string, object>)connection.Query(sql).First();
row["A"].IsEqualTo(1);
row["B"].IsEqualTo("two");

Solution 2

Regarding the portion of the title "or index?" - I needed to access results by index since the column names being returned changed sometimes, so you can use a variation of Sam Saffron's answer like this:

var sql = "select 1, 'two'";
var row = (IDictionary<string, object>)connection.Query(sql).First();
row.Values.ElementAt(0).IsEqualTo(1);
row.Values.ElementAt(1).IsEqualTo("two");

Solution 3

There a simple way to access fields direct below sample

string strConexao = WebConfigurationManager.ConnectionStrings["connection"].ConnectionString;

conexaoBD = new SqlConnection(strConexao);
conexaoBD.Open();

var result = conexaoBD.Query("Select Field1,Field2 from Table").First();

//access field value result.Field1 
//access field value result.Field2

if (result.Field1 == "abc"){ dosomething}
Share:
11,661

Related videos on Youtube

Jay Stevens
Author by

Jay Stevens

The first computers I programmed on were an IBM 8088 and then a Color Apple 2. I graduated in 1986 to a Mac-Plus so that I could record digital sequenced music. (What's the most powerful computer in the world? The one people use.) ... then I upgraded to dual floppy drives (Chuck Yeager Flight Simulator required it), then upgraded to a 40MB HD (all my MIDI programming demanded it), but then I was seduced by the PC-Master Race. (What's the most powerful computer in the world? The one that has software to run on it.) In 1990, I discovered SAS, SPSS and Statistics. So while I am .NET/Typescript/HTML/PWA geek architect; I am also a SAS-Ninja-Shadow-Warrior, machine learning, analytics, jedi master and data wrangler as well.

Updated on November 06, 2020

Comments

  • Jay Stevens
    Jay Stevens over 3 years

    I am pulling in a Dapper FastExpando object and want to be able to reference the column names dynamically at run time rather than at design/compile time. So I want to be able to do the following:

    var testdata = conn.Query("select * from Ride Where RiderNum = 21457");
    

    I want to be able to do the following:

    foreach( var row in testdata) {
        var Value = row["PropertyA"];
    }
    

    I understand that I can do:

    var Value = row.PropertyA;
    

    but I can't do that since the name of the property i'm going to need won't be known until runtime.

    The answer from this SO Question doesn't work. I still get the same Target Invocation exception. So...

    Is there any way to do what I want to do with a Dapper FastExpando?

  • crush
    crush over 9 years
    I find myself always using FirstOrDefault() and still having to check if row is null first before trying to access the row index. Is there a way to try and fetch a column value or a specific row, or return a default value if it doesn't exist?