Esri Redistricting Online - Selecting Features by Location

The Select Features by Location tool works in conjuncton with geography assignments, such as One Stage and Two Stage assignments. The Select Features by Location tool allows you to provide an SQL query expression that is used to select features that match the selection criteria.

For example, you may use the Select Features by Location tool to locate all districts where the Black voting age population (Black18) is greater than 25,000, or you can apply a spatial filter by locating all districts that match your criteria above and that intersect a defined geographic region. The Select Features by Location tool also lets you filter the data layer by specific attributes.

The Select Features by Location tool is versatile and will let you select features using different filter methods. Once selected, you can assign features using the One Stage or Two Stage geography assignment methods.

This topic explains how to select features using any combination of the following options:

Filter the query layer by attribute

The Filter the query layer by attribute option lets you create an SQL query expression using attributes from the query layer.

Steps:

On the Create ribbon, change the Active District drop-down menu to the desired district.
Because the Select Feature by Location tool lets you assign selections to the active district, you need to ensure the active district drop-down menu is set to the desired district.
Zoom to the desired data layer if you will be including a data layer attribute query (Optional).
The data layer is dependent on the plan hierarchy, for example, County-VTD-Block or County-Tract-Block Group-Block. The current display level determines the data layer used in the data layer attribute query.
On the Create ribbon, click Selection Menu.
Click Select by Location.
Choose a query layer from the drop-down menu.
Select a spatial relation from the drop-down menu.
Check the Filter by Attribute option.
The Filter the Query Layer by Attribute option expands to display a query builder.
Create an SQL expression using the query builder.
To add a field to the expression, double-click the field. You can single-click a field to enable the Get Sample Values button. Click the Get Sample Values button to view sample values for the selected field.
Apply the Filter the Query Layer by Selection option in conjunction with your feature selection (Optional). For more information on how to apply the spatial selection, see Filter the query layer by selection.
Apply the Filter the Data Layer by Attribute option (Optional). For more information on how to apply data layer attributes, see Filter the data layer by attribute.
Select how to apply the selection results:
- One Stage automatically assigns the selection results to the active district.
- Two Stage lets you preview the selection results on the map before assigning to the active district.
Caution:
The assignment type will assign geographies and/or propose geographies to the active district. Ensure you change the active district to the desired district before proceeding. The active district can be changed on the Home ribbon and selecting the district from the Active District drop-down menu.
Click OK.
The Select Features dialog box closes. The assignments are determined by the assignment choice selected above.
If you selected One Stage assignments, the selection results will automatically be assigned to the active district. For more information on One Stage assignments, see One Stage geography assignment.
If you selected Two Stage assignments, the selection results are highlighted on the map. You can click the Proposed tab on the District Statistics window to view all districts affected by the proposed assignment. For more information on Two Stage assignments, see Two Stage geography assignment.

Filter the query layer spatially

The Filter the query layer spatially option lets you draw a region spatially on the map to select features from the query layer.

Steps:

On the Create ribbon, change the Active District drop-down menu to the desired district.
Because the Select Feature by Location tool lets you assign selections to the active district, you need to ensure the active district drop-down menu is set to the desired district.
If you include a data layer attribute query, zoom to the desired data layer (Optional).
The data layer is dependent on the plan hierarchy, for example, County-VTD-Block or County-Tract-Block Group-Block. The current display level determines the data layer used in the data layer attribute query.
On the Home ribbon, click Selection Menu.
Click Select by Location.
Choose a query layer from the drop-down menu.
Select a spatial relation from the drop-down menu.
Check the Filter Spatially option.
The Filter Spatially option expands to display selection tools.
Click to enable one of the selection tools.

Selection tools include:

Draw a point lets you select a geography by point selection.
Draw a rectangle lets you select geographies by rectangle selection.
Draw a polygon lets you select geographies by polygon selection.
Draw a line lets you select geographies using a line selection.

Define a geography selection on the map.
The geography selection is displayed on the map. A Delete button appears in the Select Features by Location dialog box. This lets you delete your geography selection to define a new spatial selection.
Apply the Filter the query layer by Attribute option (Optional). For more information on how to apply query layer attributes, see Filter the query layer by attribute.
Apply the Filter the data layer by Attribute option (Optional). For more information on how to apply data layer attributes, see Filter the data layer by attribute.
Select how to apply the selection results:
- One Stage automatically assigns the selection results to the active district.
- Two Stage lets you preview the selection results on the map before assigning to the active district.
Caution:
The assignment type will assign geographies and/or propose geographies to the active district. Ensure you change the active district to the desired district before proceeding. The active district can be changed on the Create ribbon and selecting the district from the Active District drop-down menu.
Click OK.
The Select Features dialog box closes. The assignments are determined by the assignment choice selected above and matches the geography selection.
If you selected One Stage assignments, the selection results will automatically be assigned to the active district. For more information on One Stage assignments, see One Stage geography assignment.
If you selected Two Stage assignments, the select results are highlighted on the map. You can click the Proposed tab on the District Statistics window to view all districts affected by the proposed assignment. For more information on Two Stage assignments, see Two Stage geography assignment.

Filter the data layer by attribute

The Filter the data layer by attribute option lets you filter your selection by attributes in the data layer.

Steps:

On the Create ribbon, change the Active District drop-down menu to the desired district.
Because the Select Feature by Location tool lets you assign selections to the active district, you need to ensure the active district drop-down menu is set to the desired district.
Zoom to the desired data layer.
The data layer is dependent on the plan hierarchy, for example, County-VTD-Block or County-Tract-Block Group-Block. The current display level determines the data layer used in the data layer attribute query.
On the Home ribbon, click Selection Menu.
Click Select by Location.
Choose a query layer from the drop-down menu.
Select a spatial relation from the drop-down menu.
Check the Filter the Data Layer by Attribute option.
Caution:
The data layer is automatically determined by the display level. Zoom in or zoom out from the map to change to the desired data layer. For example, you may need to zoom in if the desired data layer is Tract; you will need to zoom in on the map to display Tracts.
The Filter the Data Layer by Attribute option expands to display a query builder.
Create an SQL expression using the query builder.
To add a field to the expression, double-click the field. You can single-click a field to enable the Get Sample Values button. Click the Get Sample Values button to view sample values for the selected field.
Apply the Filter the Query Layer by Attribute option (Optional). For more information on how to apply query layer attributes, see Filter the query layer by attribute.
Apply the Filter the Query Layer by Selection option in conjunction with your feature selection (Optional). For more information on how to apply the spatial selection, see Filter the query layer by selection.
Select how to apply the selection results:
- One Stage automatically assigns the selection results to the active district.
- Two Stage lets you preview the selection results on the map before assigning to the active district.
Caution:
The assignment type will assign geographies and/or propose geographies to the active district. Ensure you change the active district to the desired district before proceeding. The active district can be changed on the Create ribbon and selecting the district from the Active District drop-down menu.
Click OK.
The Select Features dialog box closes. The assignments are determined by the assignment choice selected above.
If you selected One Stage assignments, the selection results will automatically be assigned to the active district. For more information on One Stage assignments, see One Stage geography assignment.
If you selected Two Stage assignments, the results are highlighted on the map. You can click the Proposed tab on the District Statistics window to view all districts affected by the proposed assignment. For more information on Two Stage assignments, see Two Stage geography assignment.

4/16/2012