This request will return a list that contains the IDs of all levels, as well as branches. While it is possible to query against a single level of geography, census tracts for example, the GeoEnrichment service data contains information which defines a hierarchy in order to help guide application developers and end users to the results they want. This hierarchy is defined in the \u201cbranches\u201d section of the response and will be discussed later in this post. Notice that the \u201clevels\u201d section of the response contains a field “isWholeCountry”. Each country will have one record returned which represents the entire country and it will have “‘isWholeCountry’ : true,”. The whole country level will be the first level into which we need to drill in order to get to our final result. In this case, US.WholeUSA is the ID of the level where this attribute is true. To find the most direct path to query census tracts, I need to know the ID for the census tracts level.<\/p>\n
If I search for \u201ccensus tracts\u201d in my browser, I find the following entry:<\/p>\n
{\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"id\" : \"US.Tracts\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"name\" : \"Census Tracts\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"isWholeCountry\" : false,\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"adminLevel\" : \"\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"singularName\" : \"Census Tract\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"pluralName\" : \"Census Tracts\"\n\u00a0\u00a0\u00a0\u00a0\u00a0 },<\/pre>\nFrom this record, I take the ID, which is \u201cUS.Tracts\u201d and perform a search for this value in my browser window. This will help me to find if there are any branches that lead me to the census tract level. My search returns:<\/p>\n
{\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"id\" : \"USbySTbyCYbyTR\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"name\" : \"US by Tracts\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"levels\" : [ \"US.States\", \"US.Counties\", \"US.Tracts\" ]\n\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/pre>\nThis lets me know that census tract features each intersect only one feature in the counties level and that counties each intersect only one feature in the States level. The states, being the highest level listed in this branch, are all contained inside of the entire country.<\/p>\n
An example of using the branches to drill into the levels of geography to analyze a single feature can be demonstrated with the Business Analyst Web Application using the option of selecting a geography from the full list in the \u201cDefine Areas for Reports\u201d > \u201cSelect Geography\u201d menu. I\u2019ve provided some screen shots of the Business Analyst Web Application to show this in action. First, I need to navigate through a menu of options where I will ultimately wind up with the option to pick from a list of geography levels. Step 1, I choose to \u201cDefine Areas for Reports\u201d and choose \u201cSelect Geography\u201d:<\/p>\n
Next, I choose to \u201cSelect from Full List\u201d:<\/p>\n
Being that it is a \u201cfull list\u201d, it will need to start with the list of geography levels, then drill into our desired level to get the list of features in that level. When the click for \u201cSelect from Full List\u201d is selected, the \u201cStandardGeographyLevels\u201d request, which is described above, is sent. The Business Analyst Web Application then associates each of the levels with an image and the result is here:<\/p>\n
![\"List](\"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2017\/07\/bao-full-list-133x300.jpg\")
<\/a><\/p>\nSince, I am looking to pick from random census tracts, I click on the \u201cCensus Tracts\u201d. The Business Analyst Web Application uses the response from the StandardGeographyLevels request to query the branches which lead me to the \u201cUS.Tracts\u201d level. The only entry leading to the census tracts level is listed above. This results in one possible branch and is displayed in the application as a menu to \u201cSelect the State > County > Census Tracts\u201d:<\/p>\n
![\"\"](\"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2017\/07\/CTBranch-181x300.png\")
<\/a><\/p>\nWhen I click on the menu\u2019s drop down a request is executed which will list all states that fall within the entire country. Here is an example of the request:<\/p>\n
https:\/\/geoenrich.arcgis.com\/arcgis\/rest\/services\/World\/GeoenrichmentServer\/StandardGeographyQuery\/execute?langCode=en-us&sourceCountry=US&optionalCountryHierarchy=census&geographyLayers=[“US.WholeUSA”]&geographyIDs=[“01”]&returnSubGeographyLayer=true&subGeographyLayer=US.States&featureLimit=5000&f=json<\/a><\/p>\nCalifornia is listed in the drop down menu as an option for me to choose. The record for California from the response to the request above is here:<\/p>\n
{\n\"attributes\" : {\n\"DatasetID\" : \"USA_ESRI_2017\",\n\"DataLayerID\" : \"US.States\",\n\"AreaID\" : \"06\",\n\"AreaName\" : \"California\",\n\"MajorSubdivisionName\" : \"California\",\n\"MajorSubdivisionAbbr\" : \"CA\",\n\"MajorSubdivisionType\" : \"State\",\n\"CountryAbbr\" : \"US\",\n\"Score\" : 100,\n\"ObjectId\" : 5\n}\n}<\/pre>\nThe next request that I send to the server will use some information from this record, like the DataLayerID and AreaID along with the DataLayerID of the counties level from the StandardGeographyLevels request, to ask for a list of all counties in the State of California:<\/p>\n
https:\/\/geoenrich.arcgis.com\/arcgis\/rest\/services\/World\/GeoenrichmentServer\/StandardGeographyQuery\/execute?langCode=en-us&sourceCountry=US&optionalCountryHierarchy=census&geographyLayers=[%22US.States%22]&geographyIDs=[%2206%22]&returnSubGeographyLayer=true&subGeographyLayer=US.Counties&featureLimit=5000&f=pjson<\/a><\/p>\nSince there is another level of geography between the US.States level and the census tracts on this branch, this results in another drop-down in the menu where I can choose which county I want to search in:<\/p>\n
![\"\"](\"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2017\/07\/CTBranch2-171x300.png\")
<\/a><\/p>\nThe drop-down menu is populated with the names of each county in the State of California. I have decided that I am interested in a random area in San Bernardino County, so I search the list for \u201cSan Bernardino County\u201d. If looking at the response to my request, I find the following record for San Bernardino County:<\/p>\n
{\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"attributes\" : {\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"DatasetID\" : \"USA_ESRI_2017\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"DataLayerID\" : \"US.Counties\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"AreaID\" : \"06071\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"AreaName\" : \"San Bernardino County\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"MajorSubdivisionName\" : \"California\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"MajorSubdivisionAbbr\" : \"CA\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"MajorSubdivisionType\" : \"State\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"CountryAbbr\" : \"US\",\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"Score\" : 100,\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"ObjectId\" : 36\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\n\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/pre>\nFrom this record, I use the \u201cAreaID\u201d and \u201cDataLayerID\u201d with the help of the \u201cDataLayerID\u201d for Census Tracts from the \u201cStandardGeographyLevels\u201d request in the beginning, I am able to build a request which asks for all of the census tracts in San Bernardino County:<\/p>\n
"}]},"yoast_head":"\n