Data Insertion

Data Models

Data is stored and structured in CaosDB using a concept of RecordTypes, Properties, Records etc. If you do not know what these are, please look at the chapter Data Model in the CaosDB server documentation.

In order to insert some actual data, we need to create a data model using RecordTypes and Properties (You may skip this if you use a CaosDB instance that already has the required types). When you create a new Property you must supply a datatype. So, let’s create a simple Property called “a” of datatype double. This is very easy in pylib:

a = db.Property(name="a", datatype=db.DOUBLE)

There are a few basic datatypes like db.INTEGER, db.DOUBLE, or db.TEXT. See the data types for a full list.

We can create our own small data model for e.g. a simulation by adding two more Properties and a RecordType:

b = db.Property(name="b", datatype=db.DOUBLE)
epsilon = db.Property(name="epsilon", datatype=db.DOUBLE)
recordtype = db.RecordType(name="BarkleySimulation")
container = db.Container()
container.extend([a, b, epsilon, recordtype])

Inheritance of Properties

Suppose you want to create a new RecordType “2D_BarkleySimulation” that denotes spatially extended Barkley simulations. This is a subtype of the “BarkleySimulation” RecordType above and should have all its parameters, i.e., properties. It may be assigned more, e.g., spatial resolution, but we’ll omit this for the sake of brevity for now.

rt = db.RecordType(name="2D_BarkleySimulation",
               description="Spatially extended Barkley simulation")
# inherit all properties from the BarkleySimulation RecordType
rt.add_parent(name="BarkleySimulation", inheritance="all")

print(rt.get_property(name="epsilon").importance) ### rt has a "epsilon" property with the same importance as "BarkleySimulation"

The parameter inheritance=(obligatory|recommended|fix|all|none) of Entity.add_parent() tells the server to assign all properties of the parent RecordType with the chosen importance (and properties with a higher importance) to the child RecordType automatically upon insertion. See the chapter on importance in the documentation of the CaosDB server for more information on the importance and inheritance of properties.


The inherited properties will only be visible after the insertion since they are set by the CaosDB server, not by the Python client.

Insert Actual Data

Suppose the RecordType “Experiment” and the Property “date” exist in the database. You can then create single data Records by using the corresponding python class:

rec = db.Record()
rec.add_property(name="date", value="2020-01-07")

Here, the record has a parent: The RecordType “Experiment”. And a Property: date.

Note, that if you want to use a property that is not a primitive datatype like db.INTEGER and so on, you need to use the ID of the Entity that you are referencing.

rec = db.Record()
rec.add_property(name="report", value=235507)
rec.add_property(name="Analysis", value=230007)

Of course, the IDs 235507 and 230007 need to exist in CaosDB. The first example shows how to use a db.REFERENCE Property (report) and the second shows that you can use any RecordType as Property to reference a Record that has such a parent.

Most Records do not have name however it can absolutely make sense. In that case use the name argument when creating it. Another useful feature is the fact that properties can have units:

rec = db.Record("DeviceNo-AB110")
rec.add_property(name="weight", value="1749", unit="kg")

If you are in some kind of analysis you can do this in batch mode with a container. E.g. if you have a python list analysis_results:

cont = db.Container()
for date, result in analysis_results:
   rec = db.Record()
   rec.add_property(name="date", value=date)
   rec.add_property(name="result", value=result)


Useful is also, that you can insert directly tabular data.

from caosadvancedtools.table_converter import from_tsv

recs = from_tsv("test.csv", "Experiment")

With this example file test.csv.

List Properties

As you may already know, properties can also have list values instead of scalar values. They can be accessed, set, and updated as you would expect from any list-valued attribute in Python, as the following example illustrates.

import caosdb as db
db.Property(name="TestList", datatype=db.LIST(db.DOUBLE)).insert()
    name="TestList", value=[1,2,3]).insert()
retrieved = db.Record(name="TestRec").retrieve()
retrieved.get_property("TestList").value += [4,5]

# Check update
retrieved = db.Record(name="TestRec").retrieve()

File Update

Updating an existing file by uploading a new version.

  1. Retrieve the file record of interest, e.g. by ID:

import caosdb as db

file_upd = db.File(id=174).retrieve()
  1. Set the new local file path. The remote file path is stored in the file object as file_upd.path while the local path can be found in file_upd.file.

file_upd.file = "./supplements.pdf"
  1. Update the file: