Devart Forums

Hi,

When i am adding an new table to an existing dataset, which the existing table on the dataset has an foregin key relation to the newly added table, the designer fires an error. " Faild to merge object(s) error- object reference does no set to an instance of object"

When i try to find the reason, "because there are alot of other datasets which has more then one tables, was created without any problem. I checked out that the difference was the column name. If the the related-fk constraint column has differen name than the related table, this exception is fired otherwise it works fine.

Table Example,

CREATE TABLE COUNTRIES
(
COUNTRY_CODE VARCHAR2(4) NOT NULL,
COUNTRY_NAME VARCHAR2(50)
);

ALTER TABLE COUNTRIES ADD (CONSTRAINT COUNTIRES_PK PRIMARY KEY(COUNTRY_CODE));

CREATE TABLE ACTIVE_COUNTRIES
(
ACTIVE_COUNTRY_CODE VARCHAR2(4) NOT NULL,
STATUS VARCHAR2(1) NOT NULL,
ACTIVATION_DATE DATE
);

ALTER TABLE ACTIVE_COUNTRIES ADD (CONSTRAINT ACTIVE_COUNTRIES_PK PRIMARY KEY(ACTIVE_COUNTRY_CODE));

ALTER TABLE ACTIVE_COUNTRIES ADD CONSTRAINT ACTIVE_COUNTRIES_FK FOREIGN KEY(ACTIVE_COUNTRY_CODE REFERENCES COUNTRIES(COUNTRY_CODE));

How can we fix this problem whithout changing the column names.

Thanks.

[/quote]

Please specify the exact version of dotConnect for Oracle you are using. If it is not the latest 5.70.146 version, could you please check if the problem can be reproduced with it? Also, are you using Devart DataSets or DataSets created with the standard Microsoft DataSet designer?

At the moment, we couldn't reproduce the issue.

StanislavK

The installed version is 5.70.146 , I have used both designers.

I try to create an example project .

Hi,

While i tried to create an example, the behavior changes !, I dont know why.
I've createa an new schema and and add this two tables.

First, i have created an dataset using the devart wizard. I was supprised because the relation was created. But when i try to edit the relation i got an diffrent exception "the relation editor cannot be opened be.... Object reference not set to an instance of...."

Second, i have used the microsoft designer. Add->new item -> dataset,
then, draged an drop the tables form the devart database explorer. I got the same error which i have described it my firt post. Thus unable to add the countries table.

OS Version: Windows 7 enterprise x64
Devart Version: 5.70.146
Oracle 11GR2 on Windows2008 x64
Visual studio 2010

Note: Have you created the foregin key
I am sending the example by email.

Thanks
[/code]

We've reproduced the problems and are investigating them. We will inform you about the results as soon as possible.

I Have the same problem with last build (5.70.152.0) ,VS2010 and OracleXE 10.2.
With .NET Framework Data Provider for Oracle the same tables work's fine.
Any chance to solve it ?

The way i used to overcome this problem is not nice. I've droped the fk in the database and then design the dataset, then recreate the fk in the database. And hope that i do not need to re-design the dataset

We are working on the issue, but cannot provide any timeframe. We will inform you here when the problem is resolved.

ionutop, you can use the workaround suggested by ragipsavas at the moment. After both tables are added to the data set, it should be possible to create the relation manually. Please tell us if this helps.

I can wait for your solution.We try to finish other implementations first.
I'll wait news from you.

Best regards

Hi everybody,

Has this issue been corrected ?
I'm using VS2010 with dbForge Fusion 4.50.304 and dotConnect 5.80.180.0, and get the same error ragipsavas has got.

Thanks.

Regards.
Alain

We are still working on the issue, we will inform you here as soon as the problem is fixed.