Making Use of Query Layers & Spatial Views

Making Use of Query Layers & Spatial Views

Michael OlkinTown of Amherst, MA

www.amherstma.gov/maps

Technical Talk in Lightning Format

Will this work?

Query Layers & Spatial Views

• Data is Direct from your Databases• Data Represented via SQL • Work with ArcGIS for Desktop & Server*

What Are They?

Query Layer

•SQL Query in ArcGIS Desktop

Spatial View

•SQL Query in your relational database

What Do They Do?

Query Layer

• Spatial Data from tabular sources

• Supports ST_Geometry

Spatial View

• A View within a Geodatabase

• Represents existing spatial data

Query Layer Use Case

• Scenario– MassGIS Parcel

Standard unique centroid-based “LOC_ID”

– When I split a parcel, I want to know whether I need to change the LOC_ID of the original parcel

Show the LOC_ID Points via ST_Geometry

SELECT MAP_PAR_ID, LOC_ID,CAST('POINT (' + CAST(CAST(substring(LOC_ID,3,6) as int) AS varchar) + ' ' + CAST(CAST(substring(LOC_ID,10,7) as int) AS varchar) + ')' AS geometry) AS SHAPE,'POINT (' + CAST(CAST(substring(LOC_ID,3,6) as int) AS varchar) + ' ' + CAST(CAST(substring(LOC_ID,10,7) as int) AS varchar) + ')' as [ReadTheGeometry],FROM <MyParcelFeatureClass>

X Y

Show the LOC_ID Points via ST_Geometry

SELECT MAP_PAR_ID, LOC_ID,CAST('POINT (' + CAST(CAST(substring(LOC_ID,3,6) as int) AS varchar) + ' ' + CAST(CAST(substring(LOC_ID,10,7) as int) AS varchar) + ')' AS geometry) AS SHAPE,'POINT (' + CAST(CAST(substring(LOC_ID,3,6) as int) AS varchar) + ' ' + CAST(CAST(substring(LOC_ID,10,7) as int) AS varchar) + ')' as [ReadTheGeometry],FROM <MyParcelFeatureClass>

X Y

Create a Query Layer in ArcMap

Make a Query Layer with ArcToolbox

Data Management Tools -> Layers & Query Views -> Make Query Layer

Resulting Query Layer

Query Layer in Action

• Amherst Work Orders ArcGIS Online Map

Work Order Software geocodes & stores X/Y coordinates in a table

Yay! Query Layer Goodness!

Because every presentation needs a smiling cat

Spatial Views

• Warning! Legacy Solution for GDBs stored in a RDBMS (ie., ArcSDE)

• More robust than an ArcGIS Desktop Join• Requires ArcSDE Command Line Tools

(to be installed on the client)

Setting Up a Spatial View

• Command Line (ugh…ok, not so bad)• Keep it simple on the setup; edit later• GDB table registry references source feature class

sdetable -o create_view -T <NewViewName> -t <TheSpatialTable>,<TheJoinedTable> -c SHAPE,<TheJoinedTable>.<Field1>,TheSpatialTable.<Field1> -w "<TheJoinedTable>.<Field1> = TheSpatialTable.<Field1>" -i sde:sqlserver:<InstanceName> -D <DatabaseName> -u <AdminUserName> -p <AdminPassword>

Spatial View: a regular database view

• Edit it in your database, like any other viewSELECT P.SHAPE,

ROW_NUMBER() OVER(ORDER BY c.PID) as OBJECTID, C.PID, P.Map_Lot,C.PIN as MapBlockLot,C.Location, C.Number_Char as AddressNum, C.Street, C.Owner_Name 

FROM <TheSpatialTable> AS P LEFT OUTER JOIN <TheJoinedTable> AS C ON P.Map_Lot = C.Map_Lot

SQL Server tsql example: ROW_NUMBER is used here to create a unique OBJECTID

Spatial View: One to Many Join!• “Fake Out” ArcGIS with a clever query– ArcGIS draws stacked features for duplicates if each one

has a unique OBJECTIDSELECT P.SHAPE,

ROW_NUMBER() OVER(ORDER BY c.PID) as OBJECTID, C.PID, P.Map_Lot,C.PIN as MapBlockLot,C.Location, C.Number_Char as AddressNum, C.Street, C.Owner_Name 

FROM <TheSpatialTable> AS P LEFT OUTER JOIN <TheJoinedTable> AS C ON P.Map_Lot = C.Map_Lot

SQL Server tsql example: ROW_NUMBER is used here to create a unique OBJECTID

ROW_NUMBER() OVER(ORDER BY c.PID) as OBJECTID,

Stacked Parcels with a Spatial View

Yay! Spatial View Goodness!

Because every presentation needs a smiling cat

Making Use of Query Layers & Spatial Views

Michael OlkinTown of Amherst, MA

www.amherstma.gov/maps