Utility code on how to build and query Timestream db containing candlesticks

query-candles-from-timestream.ts

import {QueryCommand, QueryCommandInput} from "@aws-sdk/client-timestream-query";


export function minDifferenceDates(d1:Date, d2:Date) {
  const differenceMs = d1.getTime() - d2.getTime();
  return Math.abs(differenceMs / (1000 * 60));
}

export function minutesAgo(agoMinutes:number) {
  const now = new Date().getTime();
  return Math.round((now - agoMinutes) / (1000 * 60));
}


export const getAll = (databaseName:string, databaseTable:string) => {
  return `SELECT * FROM "${databaseName}"."${databaseTable}"`;
};

export const getWhere = (field:string, value:string, cmd='=') => {
  return `WHERE ${field} ${cmd} '${value}'`;
};

export const andTime = (field:string, value:string, cmd='=') => {
  if (value.includes('NaN')) {
    return '';
  }
  return `AND ${field} ${cmd} ${value}`;
};

export const getGroupBy = (field:string) => {
  return `GROUP BY ${field}`;
};

export const getAllWhere = (databaseName:string, databaseTable:string, filters:Array<{field:string;value:string}>) => {

  const all = getAll(databaseName, databaseTable);

  if (filters.length==0) {
    return all;
  }

  const allWheres = filters.map((el)=>{
    return el.field + ' = ' + '\''+el.value+ '\'';
  }).join(' AND ');

  return all + ' WHERE ' + allWheres;
};

export const getWhereBetweenTimeStamps = (
  databaseName:string,
  databaseTable:string,
  filters:Array<{field:string;value:string}>,
  msStart:number,
  msEnd:number):string => {

  const filtered = getAllWhere(databaseName, databaseTable, filters);

  if (msEnd<msStart) {
    throw Error('msEnd<msStart on getWhereBetweenTimeStamps');
  }

  const hoursAgoStart = minutesAgo(msStart);
  const hoursAgoEnd = minutesAgo(msEnd);

  return `${filtered} AND time > ago(${hoursAgoStart}m) AND time < ago(${hoursAgoEnd}m)`;
};