Within attribute view on a web map, there is a number of different things you can do:

In order to use our SQL query tool, you must first navigate to the "Map Viewer" mode by clicking on "View" in the top right corner of your web map or clicking the eye ball at the bottom of your map card. Once there, click on the menu icon (hamburgeler) to the right of the layer, and choose "View Attributes." At the top right of the attribute table (both in full screen and regular view) is a hamburgeler icon, which if you click on it, brings up a window choose simple "Search," "SQL," and "Download Selected" (as well as "Full Screen" and "Select by Location" if the menu was selected from the smaller attribute view). 

SQL searches allow the users to apply a number of different conditions to the search, therefore allowing for more advanced data management. Simple searches involve choosing field to search within and certain keywords or numbers to search for. We also have added an option to filter the list to only show the selected results, which is at the bottom left of the attribute table. You can also perform "Select by Location" from the attribute table menu, which allows you to draw a polygon around features you want to select. Users may also select multiple features manually by holding control or shift and clicking on them in the attribute table, which in turn highlights the features on the map itself. They may also perform multi-select by holding control and clicking on multiple features on the map itself. Then you can choose to "Download Selected" which will download whatever features have been selected. 

Note: We are using PostgreSQL 9.6 and PostGIS 2.3.4.