I'm using Pentaho for my ETL process and I'm having an issue inserting a flat file into a table with a primary key and foreign key relationship. The transformation is fairly straight forward having a Microsoft Excel Input, Add Constants, and Table Output transformations. The error I'm getting is "The INSERT statement conflicted with the FOREIGN KEY constraint". I believe that you can use a insert/update output transformation but the performance is awful. Please provide suggestions on how to resolve.
primary_key = Staff_key
foreign_key = Staff_profil_key
The table output transformation has an option to ignore insert errors. You can check this option to ignore the constraint. This option can not be used in conjunction with the batch update thus affecting performance.
Related
I am using talend for ETL I don't have enough experience in this, I am having two tables for example- account and account_roles account table is having id, name, password etc fields and account_roles table is having account_id which is f.k to account table's pk. and one more field.
Both the fields in account_roles are having duplicates, I want to save account_roles in destination with update and insert logic using talend.
But I am getting error as I don't have any table that can be treated as primary key in the account_roles table, so talend can't update or insert it.
How I deal with this situation I tried tDBOutput advance option use_field_option but still it requires unique entries.
Is there any possible solution to this issue, I also want to know if I can make table Foreign key in the account_roles table will it work then? If yes then How to make F.k in talend OPen studio is my second question.
Attaching Snapshots of my tables and tMap below -
I want to know the way I can put my tables into database if I don't have any primary key! Kindly help me.
First question
I think you should place the primary key in the physical account_roles table. Talend will use the key indication of the dbOutput component, and the physical key of the table.
In order to delete duplicates rows, you can also use a tUniqRow before the dbOutput: The key you indicate in the UniqRow is not directly linked to the database; this is only the key on which tUniqRow will be based.
Second question
It's not possible to delegate the f.k. verification to Talend. But you can do this verification in your database by placing foreign keys in your table. If an id is not present in the reference table, the database returns an error that is returned by Talend.
I'm beginer and I'm working on oracle 12c database so, In my database project I want to apply cascade on delete and on update simultaneously as i did in mysql but when i apply tha same technique in oracle it show me the error so how can i do that?
There is no ON UPDATE CASCADE on Oracle. While you can probably argue updating a table's primary key is valid in SQL, you probably should not, hence the decision of Oracle not to implement it.
More info here:
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:5773459616034
EDIT: As discussed in comments below, think of that constraint as a way Oracle prevents people from doing something wrong (updating primary keys).
The correct way to handle the case of a primary key that might be updated is to create a separate field that will act as the surrogate primary key. The surrogate key, of course, is immutable.
The danger of using a natural key as primary key is discussed there.
I have a PDM in Power Designer that I need to implement on my Oracle database.
I want to test two cases, one with the constraints like Primary Key & Foreign Key and one without those constraints.
I don't know how to do the 2nd case, do I need to use Unique Indexes ? How can it work like a fk in my diagram ? How can avoid to implement the foreign keys but still have them in my diagram ? Is there an option to not enforce the foreign key in my database ?
I can't find any or proper way to deal with the 2nd case
Thanks for your help
#pascal's comment do the trick :
On in Database > Generate Database, Options tab, in All Objects >
Table & Column > Foreign key, you have a Create foreign key checkbox
The diagram has over 40 tables, most of them have a primary key defined.
For some reason there is this one table, which has a primary key defined, but that's being ignored when I export the model to a DDL script.
This is the "offending" key (even though it's checked it is nowhere to be found on the generated DDL script):
Has anybody had the same problem? Any ideas on how to solve it?
[EDIT] This is where the key is defined:
And this is the DDL preview (yes, the primary key shows up there):
This is what happens if I try to generate the DDL for just that table (primary key still not generated):
I was finally able to identify and reproduce the problem.
It was a simple conflict of constraints.
Table MIEMBROS had a mandatory 1 to n relationship (foreign key) from another table on its primary key column and vice-versa (there was a foreign key on MIEMBROS against the other table's primary key).
This kind of relationship between two tables makes it impossible to add a record to any of them: The insert operation will return an error complaining about the foreign key restriction pointing the other table.
Anyway I realized that one of the relationships was 0 to n so I simply unchecked the "mandatory" checkbox on the foreign key definition and everything went fine.
So, in a nutshell: The Data Modeler "fails" silently if you are defining a mutual relationship (two foreign keys, one on each table against the other table) on non nullable unique columns, by not generating the primary key of one of the tables.
Such an odd behavior, if you ask me!
"This kind of relationship between two tables makes it impossible to add a record to any of them: The insert operation will return an error complaining about the foreign key restriction pointing the other table."
Actually, if you have deferred constraints, this is not impossible. The constraints can be enforced, for example, at commit time rather than immediately at insert time.
From the Data Modeler menu under File, I used Export -> DDL File. The keys appeared in the DDL, then when I went back to the diagram and did DDL Preview, it showed all the missing stuff.
I need to insert records into a table that has no primary key using LINQ to SQL. The table is poorly designed; I have NO control over the table structure. The table is comprised of a few varchar fields, a text field, and a timestamp. It is used as an audit trail for other entities.
What is the best way to accomplish the inserts? Could I extend the Linq partial class for this table and add a "fake" key? I'm open to any hack, however kludgey.
LINQ to SQL isn't meant for this task, so don't use it. Just warp the insert into a stored procedure and add the procedure to your data model. If you can't do that, write a normal function with a bit of in-line SQL.
Open your DBML file in the designer, and give the mapping a key, whether your database has one or not. This will solve your problem. Just beware, however, that you can't count on the column being used for identity or anything else if there isn't a genuine key in the database.
I was able to work around this using a composite key.
I had a similar problem with a table containing only two columns: username, role.
This table obviously does not require an identity column. So, I created a composite key with username and role. This enabled me to use LINQ for adding and deleting entries.
You might use the DataContext.ExecuteCommand method to run your own custom insert statement.
Or, you might add a primary key to a column, this will allow the objects to be tracked for inserts/updates/deletes by the datacontext. This will work even if the column isn't really an enforced primary key in the database (how would linq know?). If you're only doing inserts and never re-use a primary key value in the same datacontext, you'll be fine.