Node-red-contrib-postgresql 0.9.0 with global variables

[luis.brito]

Hi,

I'm using "node-red-contrib-postgresql 0.9.0" to change data with a PostgresSQL database.

To use variables in my query it's necessary to use {{{msg.payload.VARIABLE}}}, and it's working fine. But when i tried to use {{{global.get("VARIABLE")}}} this not work.

Can anyone help me telling the right syntax to use global variables in my case?

Thanks.

[Steve-Mcl]

Have you tried {{{global.VARIABLE}}}

[luis.brito]

Thanks for the answer!

I tested it and, does not work yet.

I have tried:

-{{{global.VARIABLE}}}
-{{{global."VARIABLE"}}}
-{{{global.get("VARIABLE")}}}

[Colin]

Exactly where are you entering that?

Also what do you mean by does not work?

[luis.brito]

In my case, i need to read the column "modelo_turno" from the table "usuario".

The query camp is working like that:

SELECT modelo_turno
FROM {{{msg.payload.schema}}}.usuario

The schema will be a string variable, because of that i am using a function node before the PostgresSQL node to read a string from a global variable and write it on the msg.payload to use in my query.

Would simplify my program if i use the global variable directly, instead of using the function all time.

[Colin]

@luis.brito

i am using a function node

So what exactly isn't working?

[luis.brito]

Everything is working, but i want to know if its possible to use the global variable instead of the msg.payload in my query.

[Steve-Mcl]

@luis.brito

but i want to know if its possible to use the global variable instead of the msg.payload in my query.

In what way. In what node (full name e.g. node-red-contrib-xxxx)?

Can you show us how you are attempting to use this format?

[luis.brito]

I'm using Node-red-contrib-postgresql 0.9.0.

[Steve-Mcl]

@luis.brito

Node-red-contrib-postgresql 0.9.0

It seems the author has elected to only support the msg object (see here: node-red-contrib-postgresql/postgresql.js at a524c9a77cd6481e6090d0dfee138c43509df574 · alexandrainst/node-red-contrib-postgresql · GitHub)

as opposed to the built in template node which supports global and flow context (node-red/packages/node_modules/@node-red/nodes/core/function/80-template.js at 702545e0b238f160cce9b339808b230f9d741b08 · Steve-Mcl/node-red · GitHub)

You could raise a request on the issues page of that node asking if the author would support accessing {{{flow.var}}} and {{{global.var}}} in the node.

That said, you are far better off using parameters (as described here: GitHub - alexandrainst/node-red-contrib-postgresql: Node-RED node for PostgreSQL, supporting parameters, split, back-pressure) as they will help you avoid the problem of quotes in string values and avoid SQL injection issues.