winnow/lib/sql-query-builder/group-by.js

Apply sql-like filters to GeoJSON

function createGroupByClause ({ groupBy, esri } = {}) {
  if (!groupBy) return ''
  const selector = esri ? 'attributes' : 'properties'
  const groups = groupBy.map(group => {
    return `${selector}->\`${group}\``
  }).join(', ')
  return ` GROUP BY ${groups}`
}

module.exports = createGroupByClause