Lab 10: Spatial Queries
You have been asked to determine what census tract that each parcel
Property is contained.
How will you find the tract number for each parcel property &
display on a map using MapInfo?
In this lesson, you will learn how to ask questions/ query multiple data
layers when the only relationship between the layers is spatial.
You will learn what spatial operators : within, contain, intersect
You will also learn what a buffer is, how to create and how to use the
spatial operators with a buffer.
To create a Spatial SQL to answer:
Which parcels are within contaminated soil?
Select File> Open Table Select parcel & contaminated soil table.
Then:
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1 Select Query
2 Select SQL Select
Spatial SQL in MapInfo
(Continued on next slide)
Continued- Spatial SQL-Which parcels are within contaminated soil?
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2 Select the tables using tables button
3 Move cursor to where condition box, select
columns button- select file. Obj
Select Operators button- select within
Select columns button- select file.obj
4 Select Verify
Answer is parcels
5 Select OK
shaded orange
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Spatial SQL
Which parcels are intersect contaminated soil?
Spatial SQL
The order of tables can change
the spatial SQL result.
If contaminated soil table listed
first, it is the base table & the
output of the SQL is one
contaminated soil record (polygon).
If parcel table listed first,
it is the base table & the
output of the SQL is many
parcel records (polygons)
Example: Buffering selected polygons at a constant distance in MapInfo & having the buffer result in
one buffer for each object:
Select File>Open Table select table to buffer; In layer control- 1 make the cosmetic layer be Editable
2 Select OK
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3 Select objects to buffer on map using arrow select
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4 Select Objects
5 Select Buffer
6 Type Radius value &
select units feet or miles
select smoothness value
select 1 buffer or multiple
7 Select OK
Buffer result
(3 buffer polygons)
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Example: Buffering selected polygons at a constant distance in MapInfo & having the buffer result in
one buffer of all objects
Buffer result
(1 buffer polygon)
You are now ready to begin MapInfo Exercise- Lab 10
Spatial Queries. The main objectives are:
• To ask questions or query data layers using:
Query> SQL Select Menu using operators of
within, contain, & intersect
• To create a buffer and using spatial operators, determine
if features from one layer are within or intersect features
from another layer
• Begin exercise- lab 10