mk-2001/node-red-contrib-postgres

A Node-RED suite to query PostgreSql

Node-red Postgres Suite

Install

Run the following command in the root directory of your Node-RED install

npm install node-red-contrib-postgres

Overview

This add-on, includes a suite of nodes to work with Postgres :

• PG Connection
• PG Insert
• PG Update
• PG Select

The first node accepts a string that represents the query to be executed.

The last 3 nodes accept an Object and outputs a Postgres query that can be used with the PG Connection node.

PG Connection

The PG Connection node accepts as a parameters an ​postgresdb​ config node, the parameter ​*Receive query output ?*​ needs to be used in the case the query produces results (like a Select).

PG Insert

The parameters for the Insert node are the name of table in which data is inserted.

The ​msg.payload​ is the data that will be inserted, this data is filtered using the ​Accepted columns​ param, in the case the param is empty - are used all the columns available on ​msg.payload​. Enabling the ​All columns required ?​ parameter, if in the ​msg.payload​ aren't available all the columns accepted by the node, the query is rejected (This param is ignored in the case the param ​Accepted columns​ is empty).

PG Update

Like the PG Insert, this node has the parameters table name and accepted column. These are the columns where the data will be updated. The parameter ​Where Columns​ works exactly like the parameter ​Accepted Columns​, the values for the where needs to be specified on the ​msg.where​

Example Input

{
   "payload" : {
       "foo" : 1,
       "bar" : "xD",
       "test": 2
   },
   "where" : {
       "foo" : 4
   }
}

PG Select

Like the ​PG Update​ node, this node accept the parameter ​Where Columns​, in that case the where clause is specified in the ​msg.payload​, in the case the ​Ignore the where clause ?​ parameter is enabled, the ​msg.payload​ and every time the node is triggered the input isn't checked.

The ​columns​ parameter are the columns that you want to select from the table, in the case a ​msg.group​ is passed to the node, the ​Group by​ parameter is overwritten, same thing for ​msg.order​

For each of the ​limit​, ​offset​ parameters, in the case the value set is different from 0, the ​msg.limit​ / ​msg.offset​ is ignored