What's the best way to model a unique rule in Prisma that matches below?
user can't add same data twice by a given field. other users can add this field.
I'm not sure I understand how #unique versus ##unique works or maybe I should be looking at something else entirely.
Related
I want to know the best way of avoiding entity duplication in an ASP.NET Core Web API project.
Imagine that you have a product with a name and manufacturer and you want to make sure if the name is not duplicated. Imagine that a new product with a name came from client (dto) and we need to look if the name (entity) already exists in the database (using EF).
You need to trim the name (name.trim()) for both names from entity and dto
You need to remove all the whitespaces in between (string.replace(" ", string.empty())
You need to change everything to lower case (string.lower())
Finally you need to compare these two
Is there any best practices how to do this without writing all the code? I tried to use string.compare with the compareoptions like ignorecase and ignoresymbols and also the string.equal() with ignorecase option but the EF gives me an alarm that it can not translate the code.
br
I have a suggestion for your approach.
Introduce another column (This can be a primary key with other keys) and save the name with trimming and lowercase when you insert a new record to that table.
Example:
Original Name : Amir Masoud Babaei -->
New Column value: amirmasoudbabaei
And when you insert a new record, do your trimming and lowercase changes and save it to the database. Since it is a primary key, it should throw an error.
So with this approach, you don't need to loop through all the names and validate if the name is already exist.
I am using go and pq to interface with my postgres database.
I have a simple user table which has basic fields. Id, name, type. My auxillary table, admin inherits from user and adds it's own field panel, and another one that is owner and adds owner. Whether that be using table inheritance, or a supporting table.
My question is if I hit and endpoint that points to user/1 at this point I don't know what type of user this person is yet here. I know we can use jwts and other ways to provide this from the front end. I'm more curious about if there is a way to figure out the user and it's type and query the additional fields in one query?
Ie. I hit the endpoint I would Select from users, get the type, then use that type to get the additional fields. So I would effectively be doing two queries on two tables to get the complete data. Is there a better solution of doing this? Is there some optimizations I could do.
I know this question might have been asked before but I have not found a single answer yet.
Basically I am using entity framework and I am in need of selecting data from a database without knowing the name of the table, as this will be generic.
Now if I do not know the table name, I do not know the type too as I have tried using context.Database.SQLQuery or context.Database.ExecuteSQLStatement but these all require the type of the object it should be expecting.
All I am receiving as parameters are the name of the table and the row ID.
Could anybody give me further advice?
Thanks.
#
Edit:
I have just been notified that the only property I would need from this table is the Name field...
I have one table.
I have to make attributes only from the fields on that table.
I have to use these attributes on one report.
I wanted to ask that all the attributes I have made are keys. Is this fine? If not, how do I resolve this issue?
The Keys are like primary, foreign keys in RDBMS. They define the joins
So long as you do not have other tables involved in the design, this is fine.
Ideally attributes are made only for dimensions
e.g
you could make attribute called Issue with forms(Issue id, Issue desc, Issue date) with Issue id as the ID form that drives the join with the other tables
All attributes should not be keys. Every key denotes that the tool is interpreting them as primary keys. Set proper relationship (parent-child) between the attributes and you will see keys only for the child attribute(s).
I have two entities: product and category (Symfony 2.3).
I want to create a form in which an user can choose a product by first selecting the category. A user selects the category by clicking on image, then I want to set the image's value into a hidden input, but I don't see how can I change a foreign entity choice list to a hidden input (http://symfony.com/doc/current/reference/forms/types/entity.html).
How can I accomplish this? (how to change form input to hidden)
If I set cascade validation to true, will it for example check if a category really exist. (To prevent putting products with non-existing category from malicious users) ?
Part 1
To do this you need to use a data transformer to do two things:
transform an entity into an identifier that is either a string or integer so a form can render it as a hidden field.
transform the string or integer identifier into the entity when the form is submitted so that the parent entity can be saved with the correct relationship
The symfony docs I linked to above (here too) actually walk though an entire example of using a data transformer with a form.
As a shameless plug (because I believe it is helpful) I have written a little tutorial on using a data transformer for a hidden field with an entity id: http://lrotherfield.com/blog/symfony2-forms-entity-as-hidden-field/
Part 2
If you are using the data transformer then you don't need to worry about malicious users. The data transformer will fail because it will not be able to reverse transform the category from the fake id. In my tutorial the transformer will throw a Symfony\Component\Form\Exception\TransformationFailedException exception.
You can also write a validator (potentially using a call back) if you wanted that checks that the submitted category is real if you want an error to show in the form. Doctrine wont allow you to persist a fake category relationship as the foreign key constraint will fail.