Npgsql 3.1.0-alpha5 does not allow passing null into a TIMESTAMP parameter for a function - npgsql

Question

I've been experimenting with coreclr on linux using the beta Npgsql library (3.1.0-alpha5). When passing parameters to a function, the library throws errors anytime a TIMESTAMP parameter is null: "Parameter <blah> must be set". Below is a test case.
create sequence sq_category_id start 1 increment 1;
create table category (
id int not null default nextval('sq_category_id'),
name varchar(16) not null,
date timestamp with time zone not null default (now() at time zone 'utc'),
active bool not null default (true),
constraint pk_category_id primary key (id),
constraint uq_category_name unique (name)
);
.. and the function
-- update
create or replace function fn_category_update(
p_id integer,
p_name character varying(16),
p_date timestamp with time zone,
p_active boolean
) returns json as
$$
declare result json = json_build_object('id', null, 'name', null, 'date', null, 'active', null);
begin
update category set
name = case
when
p_name is not null and
p_name != name and
rtrim(ltrim(p_name)) != ''
then p_name
else name
end,
date = case
when
p_date is not null and
p_date != date
then p_date
else date
end,
active = case
when
p_active is not null and
p_active != active
then p_active
else active
end
where id = p_id returning json_build_object('id', id, 'name', name, 'date', date, 'active', active) into result;
return result;
exception when others then return result;
end
$$
language plpgsql;
Anyone have an idea of what I might be doing wrong?
**Edit, here is the c# code along with the exception stack trace (which doesn't provide much additional information).
using System;
namespace Landress.Co.Models.DataObjects
{
public class CategoryDataObject
{
public int? Id { get; set; }
public string Name { get; set; }
public DateTime? Date { get; set; }
public bool? Active { get; set; }
public CategoryDataObject(int? id = null, string name = null, DateTime? date = null, bool? active = null)
{
this.Id = id;
this.Name = name;
this.Date = date;
this.Active = active;
}
public CategoryDataObject()
{
this.Id = null;
this.Name = null;
this.Date = null;
this.Active = null;
}
}
}
The code which actually makes the call to the function:
public CategoryDataObject Update(CategoryDataObject item)
{
NpgsqlConnection conn = new NpgsqlConnection(Configuration.GetSection("Data:DefaultConnection").Value);
try
{
conn.Open();
NpgsqlCommand cmd = new NpgsqlCommand("fn_category_update", conn);
cmd.CommandType = CommandType.StoredProcedure;
var paramId = cmd.CreateParameter();
paramId.ParameterName = "p_id";
paramId.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Integer;
paramId.IsNullable = false;
paramId.Value = item.Id;
cmd.Parameters.Add(paramId);
var paramName = cmd.CreateParameter();
paramName.ParameterName = "p_name";
paramName.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Varchar;
paramName.Size = 16;
paramName.IsNullable = true;
paramName.Value = item.Name;
cmd.Parameters.Add(paramName);
var paramDate = cmd.CreateParameter();
paramDate.ParameterName = "p_date";
paramDate.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Timestamp;
paramDate.IsNullable = true;
paramDate.Value = item.Date;
cmd.Parameters.Add(paramDate);
var paramActive = cmd.CreateParameter();
paramActive.ParameterName = "p_active";
paramActive.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Boolean;
paramActive.IsNullable = true;
paramActive.Value = item.Active;
cmd.Parameters.Add(paramActive);
string jsonResult = String.Empty;
try
{
jsonResult = cmd.ExecuteScalar().ToString();
cmd.Dispose();
conn.Close();
conn.Dispose();
try
{
return JsonConvert.DeserializeObject<CategoryDataObject>(jsonResult);
}
catch (Exception ex)
{
Console.WriteLine(String.Format("Unable to deserialize json result returned from postgresql: {0}", ex.Message));
return new CategoryDataObject();
}
}
catch (Exception ex)
{
Console.WriteLine(String.Format("Unable to execute postgresql function \"fn_category_update\": {0}", ex.Message));
return new CategoryDataObject();
}
}
catch (Exception ex)
{
Console.WriteLine(String.Format("Unable to open a connection to the database: {0}", ex.Message));
return new CategoryDataObject();
}
}
and finally the full stack trace.
-- Stack Trace
at Npgsql.NpgsqlParameter.ValidateAndGetLength()
at Npgsql.NpgsqlCommand.ValidateAndCreateMessages(CommandBehavior behavior)
at Npgsql.NpgsqlCommand.ExecuteScalarInternal()
at Landress.Co.Models.Repositories.CategoryRepository.Update(CategoryDataObject item) in C:\Users\<userName>\Desktop\landress.co\src\landress.co\Models\Repositories\CategoryRepository.cs:line 73
-- Message
Parameter p_date must be set

Answer 1

Should have used System.DBNull instead of null to represent value passed to the function. Not an issue with the library at all.