query

const query = await $arcgis.import("@arcgis/core/rest/query");

// url to the layer of interest to query
const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3";

const count = await query.executeForCount(url, {
  where: "POP07_SQMI > 100"
});

const query = await $arcgis.import("@arcgis/core/rest/query");

// url to the layer of interest to query
const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3";

const ids = await query.executeForIds(url, {
  where: "SUB_REGION = 'Pacific'"
});
console.log(ids);  // an array of object IDs

// set the query to return a count
// of features that has most sales grouped by regions.
// top query will run against all features available in the service
const query = await $arcgis.import("@arcgis/core/rest/query");

const count = await query.executeForTopCount(url, { // autocast to TopFeaturesQuery
  where: "mag >= 6",
  topFilter: { // autocast to TopFilter
    topCount: 1,
    groupByFields: ["Region"],
    orderByFields: ["Sales DESC"],
  },
});

// Get the count and extent of the three highest magnitude earthquakes in each region.

const query = await $arcgis.import("@arcgis/core/rest/query");

const { count, extent } = await query.executeForTopExtents(url, { // autocast to TopFeaturesQuery
  where: "mag >= 6",
  topFilter: { // autocast to TopFilter
    topCount: 3,
    groupByFields: ["region"],
    orderByFields: ["mag DESC"]
  }
});

// Get the objectIds top three earthquakes
// grouped by regions and ordered by their magnitude levels
// top query will only run against earthquakes that have mag >=6.

const query = await $arcgis.import("@arcgis/core/rest/query");

const ids = await query.executeForTopIds(url, { // autocast to TopFeaturesQuery
  where: "mag >= 6",
  topFilter: { // autocast to TopFilter
    topCount: 3,
    groupByFields: ["region"],
    orderByFields: ["mag DESC"]
  }
});

const query = await $arcgis.import("@arcgis/core/rest/query");

const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3";
const { features } = await query.executeQueryJSON(url, {
  where: "STATE_NAME = 'Washington'",
  outSpatialReference: { wkid: 4269 },
  returnGeometry: true,
  outFields: ["HOUSEHOLDS"],
});

const query = await $arcgis.import("@arcgis/core/rest/query");

const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3";
const { features } = await query.executeQueryPBF(url, {
  where: "STATE_NAME = 'Washington'",
  outSpatialReference: { wkid: 4269 },
  returnGeometry: true,
  outFields: ["HOUSEHOLDS"],
});

const [query, RelationshipQuery] = await $arcgis.import([
  "@arcgis/core/rest/query.js",
  "@arcgis/core/rest/support/RelationshipQuery.js",
]);

// url to the layer of interest to query
const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/0";

// specify relationship query parameter
const queryRelationship = new RelationshipQuery({
   outFields: ["*"],
   relationshipId: relationshipId,
   objectIds: [11, 22]
});

// query related features that meet the query parameters
const featureSet = await query.executeRelationshipQuery(url, queryRelationship);
console.log("query results", featureSet);

// Query the most visited national parks in each state
// and order them by the most visited
// query will run against all features available in the service

const query = await $arcgis.import("@arcgis/core/rest/query");

const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3";
const { features } = await query.executeTopFeaturesQuery(url, { // autocast to TopFeaturesQuery
  outFields: ["State, TOTAL, Park"],
  topFilter: {  // autocast to TopFilter
    topCount: 1,
    groupByFields: ["State"],
    orderByFields: ["TOTAL DESC"]
  },
});