node-red-contrib-cratedb

A Node-RED node to query CrateDB.

Install

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

npm install node-red-contrib-cratedb

The node-red CrateDB node uses a template node to set the query and uses msg.queryParameters as params for the query. Each property in msg.queryParameters can be used as $propertyName in the query, see the 'setup params' and 'format query' node in the example. The msg it then passed to the CrateDB node. If you want the output of the query, check the 'Receive output' box in the CrateDB node. The result of the query is then set on the msg.payload property which can be sent to a http node.

Example DB

CREATE TABLE table1
(
    field1 STRING,
    field2 INTEGER
);

INSERT INTO table1(
            field1, field2)
    VALUES ('row1', 1);
INSERT INTO table1(
            field1, field2)
    VALUES ('row2',2);

Example node-red flow

Import the flow below in an empty sheet in node-red

[{"id":"168f2030.e970e","type":"cratedb","z":"d1b19967.2e4e68","hostname":"localhost","port":"5432","db":"postgres"},{"id":"37e19274.c81e6e","type":"inject","z":"d1b19967.2e4e68","name":"trigger","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"00 12 * * *","once":false,"x":135,"y":78,"wires":[["ec61e7da.139e18"]]},{"id":"3bffa50b.c4005a","type":"template","z":"d1b19967.2e4e68","name":"format query","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"select * from table1 where field2 > $param1","x":528,"y":76,"wires":[["e3ff7e9.f1c008"]]},{"id":"e3ff7e9.f1c008","type":"postgres","z":"d1b19967.2e4e68","cratedb":"168f2030.e970e","name":"","output":true,"outputs":1,"x":695,"y":72,"wires":[["9e662745.6199d8","208d526c.df72ae"]]},{"id":"9e662745.6199d8","type":"debug","z":"d1b19967.2e4e68","name":"query output","active":false,"console":"false","complete":"true","x":877,"y":198,"wires":[]},{"id":"208d526c.df72ae","type":"http request","z":"d1b19967.2e4e68","name":"","method":"POST","ret":"txt","url":"http://localhost:1880/incoming_data","x":1009,"y":79,"wires":[["e48e88e6.1b7178"]]},{"id":"e48e88e6.1b7178","type":"debug","z":"d1b19967.2e4e68","name":"http result","active":false,"console":"false","complete":"payload","x":1192,"y":79,"wires":[]},{"id":"ec61e7da.139e18","type":"function","z":"d1b19967.2e4e68","name":"setup params","func":"msg.queryParameters = msg.queryParameters || {};\nmsg.queryParameters.param1 = 1;\nreturn msg;","outputs":1,"noerr":0,"x":328,"y":74,"wires":[["3bffa50b.c4005a"]]},{"id":"f7a7d4a7.085828","type":"http in","z":"d1b19967.2e4e68","name":"","url":"/incoming_data","method":"post","swaggerDoc":"","x":231,"y":494,"wires":[["7b5aa85e.84a558","ac9432ad.536bd"]]},{"id":"687b82be.97847c","type":"http response","z":"d1b19967.2e4e68","name":"","x":835,"y":510,"wires":[]},{"id":"7b5aa85e.84a558","type":"debug","z":"d1b19967.2e4e68","name":"http input","active":false,"console":"false","complete":"payload","x":450,"y":602,"wires":[]},{"id":"ac9432ad.536bd","type":"function","z":"d1b19967.2e4e68","name":"reply to http call","func":"msg.payload='reply from http';\nreturn msg;","outputs":1,"noerr":0,"x":599,"y":444,"wires":[["687b82be.97847c"]]}]