Object reference not set to an instance of an object.

Discussion of open issues, suggestions and bugs regarding ADO.NET provider for Oracle
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Judge
Posts: 4
Joined: Wed 03 Jun 2020 08:05

Object reference not set to an instance of an object.

Post by Judge » Tue 01 Feb 2022 10:23

Hello,

i am getting the Error "Object reference not set to an instance of an object." when i try to Import my Oracle-Database 12c via the "Model" Wizard.

I use
Devart for Oracle 9.14.1369.0
Visual Studio Professional 2019 16.11.9 (Up to date).
.NET Core 3.1.
It was working fine until last week.

I tried to upgrade to the newest Devart-Version 9.16 but i get the following Error while installing.

Setup Error
The System cannot find the file specified. (Exception from HRESULT: 0x80070002).
Please contact Devart support team if you cannot solve the problem.
"Install.log" file saved in installation folder.
This is not a fatal error, setup will continue after you press OK.

I continued but then the Devart Wizard in Visual Studio is missing the provider and i cannot try to get the Database Model.

Unfortunately i meanwhile downgraded to the Version 9.14 and i cannot provide the Install.log.

Let me know, if you need it.

Thank you very much.

Judge
Posts: 4
Joined: Wed 03 Jun 2020 08:05

Re: Object reference not set to an instance of an object.

Post by Judge » Tue 01 Feb 2022 12:15

I have found the reason.
It is not possible anymore to import models which contains an foreign key to an materialized view.
Is this supposted, that it is not working anymore?

Thank you very much.

Shalex
Site Admin
Posts: 9543
Joined: Thu 14 Aug 2008 12:44

Re: Object reference not set to an instance of an object.

Post by Shalex » Wed 02 Feb 2022 10:06

1. Have you installed dotConnect for Oracle v9.16.1434 25-Jan-22 successfully?

2. Please tell us how we should modify this DDL script to reproduce the issue with lost FK to a materialized view?

Code: Select all

CREATE TABLE T1(
  ID NUMBER PRIMARY KEY,
  NAME VARCHAR2(100)
);

CREATE MATERIALIZED VIEW T1_MV AS SELECT * FROM T1;

CREATE TABLE T2(
  ID NUMBER PRIMARY KEY,
  NAME VARCHAR2(100),
  ID_T2 NUMBER,
  CONSTRAINT T1_MV_FK FOREIGN KEY (ID_T2) REFERENCES T1_MV (ID)
);
FK is detected by Entity Developer in our environment: https://prnt.sc/26nc3u0.

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