Node Red if else functionality

General
1

Hi,

I'm building an IoT MQTT platform with node red and a mysql database.
My MQTT connection is working fine as well as the database connections.

However I need to store a connected device ID in my device tabel.
Every time I receive data the device ID is send along with it so I extract the device ID from my msg.payload.

Now I first want to check if the device ID already exists in my tabel with a query.
Currently I'm doing this whith the following query:

var strQuery = "SELECT COUNT(sensorADDR) FROM co2sensor WHERE sensorADDR = "+serverADDR+";";

When the device ID doesn't exist in the tabel I would like to add it to my device tabel using.

var strQuery2 = "INSERT INTO co2sensor (sensorADDR) VALUES ('"+serverADDR+"');";

So in essence I want to do the following.

if( COUNT(deviceID) == 0)
{
var strQuery2 = "INSERT INTO co2sensor (sensorADDR) VALUES ('"+serverADDR+"');";
}
else
{
Other code
}

I've tried the following

image
image1069×367 23.1 KB

But I lose my original data from the test mqtt out.

Can anyone help me with this problem?
With kind regards
Sébastien

2

Can you get rid of the select query by using INSERT INTO table ... ON DUPLICATE KEY UPDATE ... ?

3

php - How can I do 'insert if not exists' in MySQL? - Stack Overflow

4

This did the trick, thanks!

5

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