Bagzli Bagzli - 3 months ago 32
C# Question

Insert Guid and retrieve value with dapper

I am trying to insert a record into my database and retrieve the GUID it just added in.

Let's say if I have a table with 3 columns,

GUID
,
FirstName
,
LastName
. I need to insert a new record and then get back the GUID that was just generated. The problem is that first and last name are duplicated, often. I am not quite sure how to accomplish

Here is what I tried, I know the below won't work as I am not really telling it which column to select back and I'm not sure how to tell it:

var query = @"INSERT INTO MyTable(GUID, FirstName, LastName)
SELECT
@GUID, @FirstName, @LastName);

using (var oConn = CreateConnection())
{
var test = oConn.Query<string>(query, new
{
GUID = Guid.NewGuid(),
"John",
"Doe"
}).Single();
}


The error that I get is


Sequence contains no elements

Answer

If you want only the Guid which you inserted, Why not store it in a local variable in your code and use that as needed ?

I also see some errors in your code. The below code is corrected and should work.

var guid = Guid.NewGuid();
var query = @"INSERT INTO
              MyTable (GUID, FirstName, LastName) values ( @GUID, @FirstName,@LastName);";
using (var conn =  CreateConnection())
{
    conn.Execute(query, new {  @GUID = guid, @FirstName= "John", @LastName= "Scott" });
}
// You can use the value in guid variable now. It will be Id you inserted just now