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Here we have some data that describes road network in imaginary city
Hatsfield.
The streets (roads) are represented by lines (links) that intersects in junctions.
Streets links are numbered and uniquely identified by
link_id number. Junctions identifier is
JuncNo. It is referenced by fjunc
(from-junction) and tjunc (to-junction)
columns from the Roads table.
Roads table
| link_id | fjunc | tjunc | roadname | link_len | ... |
| 112 | 18 | 8 | Archibald St | 29.39 | ... |
| 113 | 8 | 19 | Archibald St | 34.56 | ... |
| 119 | 30 | 12 | Factory Yard | 157.48 | ... |
| 122 | 7 | 8 | High Amplitude Avenue | 31.30 | ... |
| ... | ... | ... | ... | ... | ... |
Junctions table
| JuncNo | TrafficLight |
| 8 | 1 |
| 10 | 0 |
| 11 | 0 |
| 12 | 0 |
| ... | ... |
Junctions table structure:
CREATE TABLE junctions (
[JuncNo] INTEGER,
[TrafficLight] INTEGER,
[JuncName] TEXT(25));
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Roads table structure:
CREATE TABLE roads (
[link_id] INTEGER,
[FJunc] INTEGER,
[TJunc] INTEGER,
[roadname] TEXT(60),
[link_len] DOUBLE,
[cityname] TEXT(60),
[flnum] INTEGER,
[tlnum] INTEGER,
[frnum] INTEGER,
[trnum] INTEGER,
[zipcode] TEXT(12));
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This piece of Road network of Hatsfield supposed to be a
Flat Graph. That means it is build as an integrated network, and you
can create route from any given junction (begin point) to any other (destination)
junction by chosing an apropriate sequence of connected links.
sqlexamples.info
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