connection table structure

The connections table lists the possible turns from one link into another (or itself). It specifies the lane(s) in the origin and destination links that are connected, as well as the detail of topological direction in each link that corresponds to that connection.

Geometry information is provided solely for visualization purposes

Table Structure

Field	Type	NULL allowed	Default Value	Foreign key	Description
conn*	INTEGER	NO
link	INTEGER	YES		Link(link)	bidirectional link for the upstream link of the connection
dir	INTEGER	NO	0		direction (0 for ab, 1 for ba) of the upstream link of the connection
node	INTEGER	YES		Node(node)	incident node of the connection (set by POLARIS)
to_link	INTEGER	NO		Link(to_link)	downstream bidirectinal link of the connection
to_dir	INTEGER	YES			direction (1 for ab, 1 for ba) of the downstream link of the connection
lanes	TEXT	NO	‘’		number of lanes in the upstream link that can be used for the connection (not used for all models)
to_lanes	TEXT	NO	‘’		number of lanes in the downstream link that can be used for the connection (not used for all models)
type	TEXT	NO	‘’		movement type (THRU, RIGHT, LEFT, UTURN)
penalty	INTEGER	NO	0		Not used by POLARIS
speed	REAL	YES	0		Not used by POLARIS
capacity	INTEGER	NO	0		Not used by POLARIS
in_high	INTEGER	NO	0		Not used by POLARIS
out_high	INTEGER	NO	0		Not used by POLARIS
approximation	TEXT	NO	‘’		directional approximation SB (southbound), EB, NB or WB
geo	LINESTRING	YES

(* - Primary key)

The SQL statement for table and index creation is below.

CREATE TABLE IF NOT EXISTS "Connection" (
    "conn"        INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    "link"        INTEGER,
    "dir"         INTEGER NOT NULL DEFAULT 0,
    "node"        INTEGER,
    "to_link"     INTEGER NOT NULL,
    "to_dir"      INTEGER,
    "lanes"       TEXT    NOT NULL DEFAULT '',
    "to_lanes"    TEXT    NOT NULL DEFAULT '',
    "type"        TEXT    NOT NULL DEFAULT '',
    "penalty"     INTEGER NOT NULL DEFAULT 0,
    "speed"       REAL             DEFAULT 0,
    "capacity"    INTEGER NOT NULL DEFAULT 0,
    "in_high"     INTEGER NOT NULL DEFAULT 0,
    "out_high"    INTEGER NOT NULL DEFAULT 0,
    approximation TEXT    NOT NULL DEFAULT '',
    CONSTRAINT "link_fk" FOREIGN KEY("link") REFERENCES "Link"("link") ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
    CONSTRAINT "to_link_fk" FOREIGN KEY("to_link") REFERENCES "Link"("link") ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
    CONSTRAINT "node_fk" FOREIGN KEY("node") REFERENCES "Node"("node") ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED
);

SELECT AddGeometryColumn( 'Connection', 'geo', SRID_PARAMETER, 'LINESTRING', 'XY');
SELECT CreateSpatialIndex( 'Connection' , 'geo' );

create INDEX IF NOT EXISTS "idx_conn_node" ON "Connection" ("node");
create INDEX IF NOT EXISTS "idx_conn_lanes" ON "Connection" ("lanes");
create INDEX IF NOT EXISTS "idx_conn_to_lanes" ON "Connection" ("to_lanes");
create INDEX IF NOT EXISTS "idx_conn_link" ON "Connection" ("link");
create INDEX IF NOT EXISTS "idx_conn_to_link" ON "Connection" ("to_link");