I have three tables such as A, B and C. There is ManyToMany relation from table A to table B.
At the same time Table C stores the relations between table A and B.
I want a connection between the tables. For example i want to print a data in table A which relates with table B. It's ok but when i want to take it to the next level and print a data in table A which relates with table B and which relates in table C, it doesn't consider the second condition.
That's my problem.
For better understanding
A: Tv Shows
B: Actors
C: Roles
I want to display role of an actor who acts in a certain tv show. But it returns me all roles the actor has played before (Including other tv shows). But i want the result to turn me as just one role (just one tv show)
Tv Show (1st filter) > Actor (2nd filter) > Role (Result)
Problem: I can't apply 1st filter to results.
Thanks in advance.
What you want to do is to allow the role table to act as the bridge between shows and actors.
Shows 1:many Roles many:1 Actors
So when you link Show and Actor you specify which role an actor plays for a given show. Drop the Doctrine 2 many to many relation between Show and Actor and replace with two 1:many relations with roles.
After that the queries will be easy.
Related
Suppose, you want to create a rest api method for different car brands (BMW, AUDI, MERCEDES).
You also want to create a new car, including the car brand as property.
How can I validate if the car brand exist, before creating a new car in the table?
From the front-end, you want a dropdown list (select / option).
From the backend you want to validate the input.
What is the best practice for this?
The get car brands method will read the dynamodb table too often, creating hot partitions.
The API call to the DynamoDB table when attempting to create a new car brand would be to use a Conditional Put. That way you would say "only insert this new car brand if it does not exist already".
For the read of list of car brands, if this is something in your UI that is presented thousands of times per second, then i'd have an out of band lambda function that updates the list only when a new car brand is input (use DynamoDB Streams). I would put that list X number of items all with the same data, but different PKs. For example: pk = "CarBrandList_0" all the way through pk = "CarBrandList_5". In your code to get the car brand list, you give it the PK and a random number between 0 and 5. You have now avoided creating hot keys
I am struggling in the creation of a report including four tables.
Those tables should be the same for each account. I use just one dataset. When I run the report, the data is good, but tables listing appears wrong.
First all BALANCE DETAIL tables for all accounts selected are listed, then all DEBIT TRANSACTION tables for all accounts selected are listed etc.
For each account the page should show up just like this
Please give me an easy-to-understand answer since I am really a beginner in this sector.
It might be easier to this with 5 separate datasets, but I think you can do it with just on also.
Create on 'main' table on the dataset. use 4 detail rows, 1 column
Group it on accountnumber
In each detail of the main table, insert a new table with the same dataset.
Group those sub-tables also on accountnumber
Add a filter to the subtables. set the subtable accountnumber equal to the outer table account number (you can use the expression builder, but it should read something like this: row['ponum'] equals row._outer["ponum"] )
Good luck!
Hi all,
I have 3 tables in an access 2010 database:
Crew: CrewID; Name; Adres;...
Voyage: VoyageId; Voyage name; Departure harbour; Arrival harbour
Crewlist: CrewlistId, VoaygeId, CrewId, Rank
The VoaygeId and CrewId from the Crewlist table are linked (relation) to the autonumber ID's from tables 2 and 1.
My first and main question is: Upon boarding everyone has to ‘sign in’ selecting the voyage and there name, and assign them a roll (of to be donde by the responsible officer). How can I make a form that lets the users browse through the voyagenames and crewnames in stead of the ID’s uses in the ‘mother’ table (table 3: Crewlist)
2nd question: how can I make sure that someone isn’t enrolled twice for the same voyage (adding same voyagenumber and same crewId number in crewlist). This would preferably be blocked upon trying to add the same person a second time on a voyage.
To prevent duplicates in Crewlist, add a unique index to the table on both CrewId and VoyageId
It would be a good idea to add relationships and enforce referential integrity
You are now in a position to use the wizards to create a form based on Voyage and a subform based on CrewList with a combobox based on Crew
There are a number of refinements you could add.
Make sure you do not use reserved words like Name and do not put spaces in field names. You will thank yourself later.
See also create form to add records in multiple tables
i'm using Drupal 6
I have this table relation and I've translated into CCK complete with it's relation.
Basically when I view a Period node, I have tabs to display ALL Faculty nodes combined with Presence Number.
here's the table diagram: http://i.stack.imgur.com/7Y5cU.png
Translated into CCK like these:
CCK Faculty (name),
CCK Period (desc,from,to) and
CCK Presence(node-reference-faculty, node-reference-period, presence_number)
Here's my simple manual SQL query that achieve this result: http://i.stack.imgur.com/oysd3.png
SELECT faculty.name, presence.presence_number FROM Faculty AS faculty
LEFT JOIN (SELECT * FROM Presence WHERE Period_id=1) AS presence ON faculty.id=presence.Faculty_id
The value of 1 for Period_id will be given by the Period Node ID from the url argument.
Now the hardest part, is simulating simple SQL query above into Views. How can I make such query into Views in Drupal-6 or Drupal-7 ?
thanks for any helps.
The main issue, which I think you've noticed, is that if you treat Faculty as the base for your join, then there is no way to join on the Presence nodes. Oppositely, if you treat Presence as the base, then you will not see faculties that have no presence number.
There is no easy way, using your currently defined structure, to do these joins in views.
I would say your easiest option is to remove the 'node-reference-faculty' field from the presence node and add a node-reference-presence field to the faculty. Since CCK fields can have multiple values, you can still have your one-to-many relationship properly.
The one downside of this is that then you need to manage the presence-faculty relationship from the faculty nodes instead of the presence nodes. If that's a show stopper, which it could be depending on your workflow, you could have BOTH node-reference fields, and use a module like http://drupal.org/project/backreference to keep them in sync.
Once you have your reference from faculty -> presence, you will need to add a relationship in Views. Just like adding a field or a filter, open the list of relationships and find the one for your node-reference field.
Next, you will need to add an argument for period id and set it up to use a node id from the url. The key thing is that when you add the argument, it will ask which relationship to use in its options. You will want to tell it to use your newly added presence relationship.
You don't really need to do a subquery in your SQL like that. This should be the same thing and won't make mysql try to create a temporary table. I mention it because you can't really do subqueries in Views unless you are writing a very custom Views handler, but in this case you don't really need the subquery anyway.
Ex.
SELECT f.name, p.presence_number
FROM Faculty AS f
LEFT JOIN Presence AS p ON f.id=p.Faculty_id
WHERE p.Period_id=1;
I wrote an article about how to achieve a similar outcome here. http://scottanderson.com.au/#joining-a-views-query-to-a-derived-table-or-subquery
Basically how to alter a Views query to left join on a sub-query.
We are storing people's class attendance information to Drupal. We would like to show this in a grid/chart, where the first column of each row shows person's name, and rest of the columns (ca. 20) either a checkbox or "X" if the user attended a class, or otherwise an non-checked box or empty column:
(dates here)
Jack X XXX X X
Jill XX XXX XX
It should also be possible to edit the attendance information on the grid. Each attendance information is a node of its own.
This functionality can probably mostly be achieved using views and editablefields, but there is one problem: if a person has not attended a specific class he/she will not have at all an attendace node for that day. What would be the easiest way to create an attendace node in those cases, so that it would be possible for the end user to edit the grid by just clicking on the checkbox or typing an 'X'?
You could use the Rules module to automatically create the nodes.
I'm not quite sure about the functionality you want to achieve, but it sounds like a doodle like one. So you may want to check out the http://drupal.org/project/date_picker_formatter module (successor of http://drupal.org/project/dudel).