Windshaft-cartodb/lib/models/dataview/overviews/formula.js

81 lines
2.4 KiB
JavaScript

'use strict';
var BaseOverviewsDataview = require('./base');
var BaseDataview = require('../formula');
var debug = require('debug')('windshaft:widget:formula:overview');
const utils = require('../../../utils/query-utils');
var dot = require('dot');
dot.templateSettings.strip = false;
const VALID_OPERATIONS = {
count: true,
sum: true,
avg: true
};
/** Formulae to calculate the end result using _feature_count from the overview table */
function dataviewResult (ctx) {
switch (ctx.operation) {
case 'count':
return 'sum(_feature_count)';
case 'sum':
return `sum(${utils.handleFloatColumn(ctx)}*_feature_count)`;
case 'avg':
return `sum(${utils.handleFloatColumn(ctx)}*_feature_count)/sum(_feature_count) `;
}
return `${ctx.operation}(${utils.handleFloatColumn(ctx)})`;
}
const formulaQueryTpl = ctx =>
`SELECT
${dataviewResult(ctx)} AS result,
${utils.countNULLs(ctx)} AS nulls_count
${ctx.isFloatColumn ? `,${utils.countInfinites(ctx)} AS infinities_count,` : ''}
${ctx.isFloatColumn ? `${utils.countNaNs(ctx)} AS nans_count` : ''}
FROM (${ctx.query}) __cdb_formula`;
function Formula (query, options, queryRewriter, queryRewriteData, params, queries) {
BaseOverviewsDataview.call(this, query, options, BaseDataview, queryRewriter, queryRewriteData, params, queries);
this.column = options.column || '1';
this.operation = options.operation;
this._isFloatColumn = null;
this.queries = queries;
}
Formula.prototype = Object.create(BaseOverviewsDataview.prototype);
Formula.prototype.constructor = Formula;
module.exports = Formula;
Formula.prototype.sql = function (psql, override, callback) {
var self = this;
if (!VALID_OPERATIONS[this.operation]) {
return this.defaultSql(psql, override, callback);
}
if (this._isFloatColumn === null) {
this._isFloatColumn = false;
this.getColumnType(psql, this.column, this.queries.no_filters, function (err, type) {
if (!err && !!type) {
self._isFloatColumn = type.float;
}
self.sql(psql, override, callback);
});
return null;
}
var formulaSql = formulaQueryTpl({
isFloatColumn: this._isFloatColumn,
query: this.rewrittenQuery(this.query),
operation: this.operation,
column: this.column
});
callback = callback || override;
debug(formulaSql);
return callback(null, formulaSql);
};