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PetaPoco ExecuteScalar Null Pointer

I scratch my head, trying to understand why petapoco "Exists ()" returns false, where it should return true. I use something like this to check:

Simple petapoco model:

[TableName("WorkLog")]
[PrimaryKey("Id")]
public class WorkLog : DefaultConnectionDB.Record<WorkLog>
{
     public int Id { get; set; }
     public Guid? Customer { get; set; }
     public Guid? Project { get; set; }
}

A database table with the same structure as above, filled with identifiers and clients (only for the project).

Create a test object:

var x = new WorkLog {Id = 0, Customer = 'xxx-xxx-xxx...', Project = null}

The query if a DB based on "Project" exists in the DB:

var exist = db.Exists<WorkLog>("Project=@p", new { p = x.Project });

In this case, the result is false. If I populate the model, db and query using Guid for Project, it will return “true” as it should.

, , NULL DbNull, . "null" "DbNull" , false.

:

...

var exist = db.Exists<WorkLog>(x.Project == null ? "Project IS NULL" : "Project=@p", new { p = x.Project });

, , , .

+4
1

ADO.net, PetaPoco. PetaPoco Params .

null WHERE , MSDN :

Null

( ) NULL, "null". WHERE, , , null. SQL , LastName , @LastName, LastName @LastName .

SELECT * FROM Customers
WHERE ((LastName = @LastName) OR (LastName IS NULL AND @LastName IS NULL))
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