vega-transform-db v1.0.12
vega-transform-db
Data transform to load data from a database in Vega.
This package extends Vega's set of data transforms to support loading data from a database in Vega version 5.0 and higher.
Usage Instructions
Install the transform with
yarn add vega-transform-db
To use the transform, you must initially set the type
. We currently aim to support 2 types of interaction with a database either via a middleware server or directly through a query function.
So if you intend to use a server set the type to Server
or Serverless
if you're passing a query function, then register the transform as dbtransform
.
import VegaTransformDB from "vega-transform-db"
VegaTransformDB.type('Serverless');
transforms["dbtransform"] = VegaTransformDB;
Further examples for using the package with a middleware server and with a serverless query function.
API Reference
# VegaTransformDB.type(type: string = "Serverless")
- This function is used to indicate whether the transform will be interacting with a middleware server
VegaTransformDB.type('Server')
or notVegaTransformDB.type('Serverless')
# VegaTransformDB.QueryFunction(function)
- If the type has been set to
Serverless
, this function is used to indicate which query function is to be used when a sql query is encountered.
# VegaTransformDB.setHttpOptions(object)
- If the type has been set to
Server
, this function is used to set the Http POST request options, i.e,
const httpOptions = {
'url': 'http://localhost:3000/query',
'mode': 'cors',
'method': 'POST',
'headers': {
'Content-Type': 'application/x-www-form-urlencoded'
}
};
VegaTransformDB.type('Server');
vega.transforms["dbtransform"] = VegaTransformDB;
VegaTransformDB.setHttpOptions(httpOptions);
This example indicates that when a query is to be executed it will send a POST request at http://localhost:3000/query with sql query.