Two different SQLite3 Databases in one flow

[iotred3307]

Hello NodeRed Team,

I have two different sqlite3 databases in one flow. I want to select one value, each from those different databases, and compare. Unfortunately, when I change the path in one database, the other automatically gets changed as per the modified one.

How can I resolve this issue?

[Steve-Mcl]

Instead of editing the config - add a 2nd config.

Example...

[iotred3307]

Thank you very much. Now that I could pass select queries, how I can compare both the outputs and create an output that I can write to a S7 data block? I am using JOIN but cannot find a solution for that.

[Steve-Mcl]

what comes out of the join? (add a debug)

tip, use a function node & if statements to compare the 2 values

See also Writing Functions : Node-RED

[iotred3307]

The output of both the databases are attached in the snapshot. I am trying to join them manually to create an Array. Doesn't work. I think I am doing some mistake.

[Steve-Mcl]

I dont see any output from your join (you didnt set the count).

A better solution...

1. add a change node AFTER the TOP orange DB node & set msg.topic to "data1"
2. add a change node AFTER the BOTTOM orange DB node & set msg.topic to "data2"
3. Change the join node to create "key/val object" and enter 2 in the count
   

THEN operate the 2 querys and you should see something usable come out of the join node

[Colin]

Rather than using a Join node (which will work if you configure it correctly), connect them in series. Feed an inject node into the first db, then feed the result into a Change node which Moves msg.payload into a message property, msg.db1Results for example. Then feed that into the second db node . The output will then contain the second results in msg.payload and the original results should still be in msg.db1Results.

[iotred3307]

Thank so.

Sorry for asking you this basic question again. After joining data 1 and data 2, I got this. How can I put the values in the compare function?

[iotred3307]

Thank you. Will try this one.

[Steve-Mcl]

I am afraid you really need to do some learning.

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@iotred3307

How can I put the values in the compare function?

If you read the link i posted...

@Steve-Mcl

tip, use a function node & if statements to compare the 2 values

you would see your error (clue - missing parenthesis)

Additionally, where do you think object.data1 comes from? Read this to learn how to use the debug panel to find the right path to any data item: Working with messages : Node-RED

Recommended Learning...

I also recommend watching this playlist: Node-RED Essentials. The videos are done by the developers of node-red. They're nice & short and to the point. You will understand a whole lot more in about 1 hour. A small investment for a lot of gain.

Then do some basic online JavaScript training.