YAML data model specification
caosadvancedtools library features the possibility to create and update
CaosDB models using a simplified definition in YAML format.
Let’s start with an example taken from model.yml in the library sources.
Project: obligatory_properties: projectId: datatype: INTEGER description: 'UID of this project' Person: recommended_properties: firstName: datatype: TEXT description: 'first name' lastName: datatype: TEXT description: 'last name' LabbookEntry: recommended_properties: Project: entryId: datatype: INTEGER description: 'UID of this entry' responsible: datatype: Person description: 'the person responsible for these notes' textElement: datatype: TEXT description: 'a text element of a labbook recording' associatedFile: datatype: FILE description: 'A file associated with this recording' table: datatype: FILE description: 'A table document associated with this recording' extern: - Textfile
This example defines 3
Projectwith one obligatory property
A Person with a
lastName(as recommended properties)
LabbookEntrywith multiple recommended properties of different data types
It is assumed that the server knows a RecordType or Property with the name
One major advantage of using this interface (in contrast to the standard python interface) is that properties can be defined and added to record types “on-the-fly”. E.g. the three lines for
firstName as sub entries of
Person have two effects on CaosDB:
A new property with name
first nameis inserted (or updated, if already present) into CaosDB.
The new property is added as a recommended property to record type
Any further occurrences of
firstName in the yaml file will reuse the definition provided for
Note the difference between the three property declarations of
Project: This record type is added directly as a property of
LabbookEntry. Therefore it does not specify any further attributes. Compare to the original declaration of record type
responsible: This defines and adds a property with name “responsible” to
LabbookEntry`, which has a datatype ``Person.
Personis defined above.
firstName: This defines and adds a property with the standard data type
TEXTto record type
If the data model depends on record types or properties which already exist in CaosDB, those can be
added using the
extern takes a list of previously defined names.
You can use any data type understood by CaosDB as datatype attribute in the yaml model.
List attributes are a bit special:
would declare a list datatype of DOUBLE elements.
would declare a list of elements with datatype Project.
importance: Importance of this entity. Possible values: “recommended”, “obligatory”, “suggested”
datatype: The datatype of this property, e.g. TEXT, INTEGER or Project.
unit: The unit of the property, e.g. “m/s”.
description: A description for this entity.
recommended_properties: Add properties to this entity with importance “recommended”.
obligatory_properties: Add properties to this entity with importance “obligatory”.
suggested_properties: Add properties to this entity with importance “suggested”.
inherit_from_XXX: This keyword accepts a list of other RecordTypes. Those RecordTypes are added as parents, and all Properties with at least the importance
XXXare inherited. For example,
inherited_from_recommendedwill inherit all Properties of importance
obligatory, but not
parent: Parent of this entity. Same as
You can use the yaml parser directly in python as follows:
from caosadvancedtools.models import parser as parser model = parser.parse_model_from_yaml("model.yml")
This creates a DataModel object containing all entities defined in the yaml file.
You can then use the functions from caosadvancedtools.models.data_model.DataModel to synchronize the model with a CaosDB instance, e.g.: