I have a database which I want to visualize in some kind of tool. Let me explain the basic:
Company A does business with Transport Company A and Transport Company B.
Transport Company A does business with Company A, Company B and Company C.
Company C does business with Transport Company A and Transport Company B.
As you can see every Company does business with different Transport Companies and vice versa. These relationships can be implemented in a database, and when drawing a visual model on paper this is also very easy.
Of course the model should contain hundreds of Companies and Transport Companies. So I want to have a visualizing tool, where a overview of these relations can be displayed.
My question is which tools can be used for realizing this?
I think you want to look at Microsoft Visio (get the 2010 version. 2013 is almost unusable from a database standpoint).
But if i am assuming correctly, you want to create a table per company. Don't do this! this can cause redundancy and data integrity problems. you want to create just one table and create what is called a unary many-to-many relationship. This is relationship that can be translated to many different rows can relate to many rows in the same table. I won't go into more detail unless you want me to, as i spent a week or 2 in my Database Design course last month just on many-to-many relationships and gets kinda complicated.
Related
I am in process of designing a reporting tool. the Interface will be C# with backend database. The tool will allow to enter and edit data through an interface and save it to the Database. Additionally, it will provide specific reports, based on the data retrieved from DB.
Currently, I have been trying to solve a M:N relationship in for my DB tables.
The tool lets a user to enter daily Item amounts (Steel and Mesh) based on a Project. I have solved the M:N relationship in the following diagram but I am not sure if this is actually possible and whether I need to break down the daily stats table further, due to a composite key containing 4 PKs from other tables. This is the current diagram i got.
I am wondering whether the diagram has solved the M:N relationship correctly and whether there is a better way to utilise the date table.
I'm puzzling over how to set up this relationship in Laravel, (I'm converting a legacy app):
I have Repair Shops, which provide different types of repairs, on different brands of vehicles.
For example, Shop A might repair Brakes but not Exhaust Systems for Ford vehicles. Shops are required to say what services they provide, (Exhaust repair), but adding a brand is optional. I have Shop, Service, and Brand tables in the DB. Shop and Service have a belongsToMany relationship using the provides_service pivot table. In the legacy system I have a 3-way pivot table to specify what Services can be done to each Brand in each Shop.
Laravel doesn't seem to do 3-way relationships well, (or does it? If so, point me there!). So, I feel like it would make sense to create a belongsToMany between the provides_service relation and the Brand. So, is there a way to set up a relationship between a Model and another Relationship in Laravel, or do I have to create a ProvidesService model? Creating a ProvidesService model seems wasteful, but I'm not sure what else to do here.
I have some trouble to design my data warehouse. Here's the context :
Financial people register our deals and report a financial snapshot every month. When they register new deals, they also indicates some information like which equipment is sold, at which customer, etc. (our dimensions).
Project managers add additionnal data to these deals with milestones information (startup project date, customer acceptance date, etc.), also on a monthly basis.
Finance will only use finance information, Project Manager could use both type of information.
Based on this information, I have many possible scenarios, which is the best ?
1st scenario : star schema
In this scenario, I have two separate tables for Finance and Project management. But the thing is that I will have to duplicate reference to dimensions (equipment, customer, etc.) as it is Finance that declare deals and that information have to stay consistant for a same deal.
First Scenario Schema
2nd scenario : one common table
As we have the same granularity (both are monthly snapshot), we could merge Finance and Project management information in a single table and proposes two views to the users. But I fear that it will become a mess (different enterprise function in a single table...).
3nd scenario : snowflake schema
We also could add a "Deal" table, containing all references to other dimensions (customer, equipment, etc.).
Third Scenario Schema
Thanks in advice for any usefull advice !
I am designing data base for inventory management system which is used by nearly 10 to 15 companies. This database contains nearly 25 tables.For designing database i'm planning to use shared schema architecture(ie each schema corresponding to a company and these all schemas are to be placed in a single database).
i want to know whether it is reliable to use shared schema architecture.
can any one please tell me is it correct decision to use above mentioned architecture.
Thanks in advance..
If I read your question, you are suggesting that each company has its own schema. This means two things:
If you decide to implement a basic change in the schema (ie not a change that one company requests), then you will have to implement this change in all the schemae.
You will probably have to implement different logic in your front
end program for each company.
Better you should develop one schema for the entire database; each table would have a field called 'CompanyID' which naturally would define to which company each row belongs. This field would be a foreign key to the Companies table.
For a possible solution using Active Directory and Exchange see my post below.
We would like to create a training database in SQL which we can use for our internal training sessions of our employees. Unfortunately I do not have any experience in database design and did not have a chance to buy and read a proper book about this topic.
I have just started to create a database after reading a few tutorials online and would like you to review my design and provide me with some feedback if I have started more or less correct.
The courses table will store our training courses with their duration, capacity and a small description of what you will learn on this course. The training session table will be used to link a course with a specific training and a date when the training will be done. The trainers are colleagues who provide the internal courses.
The attendance table stores the training session id and if an employee attended the session or if he could not.
Please find below our database diagram:
alt text http://img8.imageshack.us/img8/2464/trainingdb.jpg
Later on we would also like to store the job position a training course is relevant for.
For example our network introduction course is relevant for a Level 1 Analysts, a Level 2 Analysts and Team Leaders. Our ITIL course is relevant only for a team leader.
How would you store this information? Would you use a separate table with the positions and use a many to many relationship for this?
Many thanks,
Mathias
The structure seems fine. I'd suggest adding one more foreign key relationship, though: Attendance.EmployeeID should reference the Employee table.
Attendance doesn't need its own primary key. The combination of employee and session uniquely identifies it (a given employee can't attend a given session more than once, can they?). You should probably use the two ID columns for those as a composite primary key.
Do courses really have a capacity, or is it a session which has a capacity?
What's the UpdateTime column for?
A bit simplified, does not account for enrolment, but may help you with ideas.
Below an explanation of the tables
We use the module category, module type, course, programme, training method and post work tables to categorize the training module using dropdown lists. The relationships are 1:n.
The module <-> employee relationship is m:n. As you can see from the model, the intersection table is Trainer where we define the additional property of Priority to allow us to define trainer priorities for a module.
The training module <-> role relationship is a many-to-many relationship as a module can be relevant to many job roles. The intersection table is RoleRelevance and we define for each role required, recommended, probation and hide properties.
The training request table keeps a record of each training request that has been requested. We also have new starter requests were we do not have a domain profile / SAM we can link the request to.
The employee table is being populated from our domain controllers with AD queries while employees are requesting a training or trainers are being defined for a module. The table includes the employee smtp address used to send invitations. See my other stackoverflow posts for a code sample how to get this data.
We create meeting invitation with managed EWS for the employee, line manager, trainer and resource/room. The invitation id and status (accept/decline/unknown) are stored in the EmployeeInvitation, TrainerInvitation and ResourceInvitation tables.
Training sessions we create are being inserted into the training session table.