Why create and use "child databases" within databases ?
If you want to separate an element database in two, you will have to create two child databases.
What is a child database within databases ?
Ermeo allows you to create databases of elements. All the elements present in the same database will have the same attributes.
In a database, one can define child databases also called "sub-databases".
In this case, there will be an inheritance of attributes. The existing attributes for the database will also exist for the child databases.
In practical, how to create child databases ?
Context : Imagine a company that inspects thousands of rails across Europe. These rails are assets stored in a database called "Rails".
Each element of the database will be characterized by the following attributes:
- Rail length
- Rail thickness
- Year of Rail
The company wants to add an attribute to qualify the rail standard. This standard is not the same between France and England.
We are going to create a first child database named "Rails England". This child database will have the attribute "England Standard".
Then, we will create a second child database named "Rails France". This child database will have the "France Standard" attribute.
1. In the Databases tab, click into a Create New database.
2. Create a new database. Name it "Rails". Dont choose any parent database
3. Add the following attributes:
- Rail Length (Number type)
- Rail thickness (Number type)
- Rail year (Number type)
4. Go back into the databases list, and create a new database. Name it Rails France. Select Rails as parent database.
5. In the database Rails France, add a multiple choices attribute and name it "Norme France".
Enter the following values for the multiple choice:
- NF 1435 mm
- NF 1700 mm
6. Repeat step 5, replacing the term France with England. Enter the following values for the multiple choice :
- NUK 1524 mm
- NUK 1628 mm
You have created your two subdatabases "Rails France" and "Rails England". These two subdatabases appear in the "Rails" database.
You can now create elements in each of the sub-databases.
- The elements created in the "Rails England" subfamily will have the attribute "England Standard.
- The elements created in the "Rails France" subfamily will have the "France Standard" attribute.