This cookie is set by GDPR Cookie Consent plugin. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category 'Functional'. The cookie is used to store the user consent for the cookies in the category 'Analytics'. These cookies ensure basic functionalities and security features of the website, anonymously. Necessary cookies are absolutely essential for the website to function properly. The actual JSON key is referenced as $.keyname ($.humidity) and is in quotes.įor the timestamp we use the JSON extract json_extract(sensor_data2.data,’$.timestamp’)

Sensor_data2.data = table_name.field_name My example flow illustrates two of them : The documentation lists all of the JSON functions that are available. let temp='update sensor_data2 set data=' Here is the actual code taken from the flow. I created a query to change the humidity value based on the timestamp. The screen shot above also illustrates how we can modify a JSON key value. The screen shot below illustrate this and the first entries were created without a timestamp and then I added a timestamp to the JSON data. We can easily expand it without having to modify the table. This time our data is simply a JSON object with time stamp,temperature and humidityr. To create our table we use: CREATE TABLE sensor_data2(DEVICE TEXT NOT NULL,DATA TEXT NOT NULL) The answer is that we need to add another field to the table which is possible but not simple. Now although the above works well and it is relatively easy to create queries for any of the fields it isn’t flexible as what happens if I need suddenly to record the atmospheric pressure? Our command to create sensor_data1 is CREATE TABLE sensor_data1(DEVICE TEXT NOT NULL,TIMESTAMP INT NOT NULL,TEMPERATURE REAL NOT NULL,HUMIDITY REAL NOT NULL) We are going to call our tables sensor_data1 and sensor data_2 and use the database called test.db Creating the Tables Storing as Individual Fields Where Data contains our time stamp,temperature and humidity stored in JSON. Note the time stamp is an integer as we are using a Unix like time stamp. If we needed to query the database on all of these fields the we would create a database scheme with the following fields: The best way to see this is via an example and so we will create two flows using database tables that use these two methods.įor our flows we are going to be storing temperature and humidity data for a group of sensors (sensor1,sensor2 etc). To accomplish this you would need to extract the key from the JSON data and create a database key for this. However prior to version 3.9 it wasn’t possible to query the database using the temperature,time or humidity keys as they are part of the JSON data.

To store this in SQLite you simple convert to JSON and store as text. In this tutorial we look at storing JSON data and retrieving it using keys instead of fields, and then look at storing time series data.Īs an example let us take a JavaScript object This changed in version 3.9 in 2015 ( SQLite history) and so there is now no need to separate out the JSON data so that you can query using a key.

However what was not previously possible was how to query this JSON data using a key. It has always been possible to store JSON Data in an SQLite database as JSON data is simply text data.

Db browser for sqlite json support