Dictionary of columns & Custom Query¶
| path: | a sequence of vertices/edges from A to B. |
|---|---|
| route: | a sequence of paths. |
Description of the edges_sql query¶
| edges_sql: | an SQL query, which should return a set of rows with the following columns:
|
|---|
Where:
| ANY-INTEGER: | smallint, int, bigint |
|---|---|
| ANY-NUMERICAL: | smallint, int, bigint, real, float |
Description of the parameters of the signatures¶
| edges_sql: | TEXT SQL query as decribed above. |
|---|---|
| start_vid: | BIGINT identifier of the starting vertex of the path. |
| start_vids: | array[ANY-INTEGER] array of identifiers of starting vertices. |
| end_vid: | BIGINT identifier of the ending vertex of the path. |
| end_vids: | array[ANY-INTEGER] array of identifiers of ending vertices. |
| directed: | boolean (optional). When false the graph is considered as Undirected. Default is true which considers the graph as Directed. |
Description of the return values¶
Returns set of (seq [, start_vid] [, end_vid] , node, edge, cost, agg_cost)
| seq: | INTEGER is a sequential value starting from 1. |
|---|---|
| route_seq: | INTEGER relative position in the route. Has value 1 for the begining of a route. |
| route_id: | INTEGER id of the route. |
| path_seq: | INTEGER relative position in the path. Has value 1 for the begining of a path. |
| path_id: | INTEGER id of the path. |
| start_vid: | BIGINT id of the starting vertex. Used when multiple starting vetrices are in the query. |
| end_vid: | BIGINT id of the ending vertex. Used when multiple ending vertices are in the query. |
| node: | BIGINT id of the node in the path from start_vid to end_v. |
| edge: | BIGINT id of the edge used to go from node to the next node in the path sequence. -1 for the last node of the path. |
| cost: | FLOAT cost to traverse from node using edge to the next node in the path sequence. |
| agg_cost: | FLOAT total cost from start_vid to node. |
Descriptions for version 2.0 signatures¶
In general, the routing algorithms need an SQL query that contain one or more of the following required columns with the preferred type:
| id: | int4 |
|---|---|
| source: | int4 |
| target: | int4 |
| cost: | float8 |
| reverse_cost: | float8 |
| x: | float8 |
| y: | float8 |
| x1: | float8 |
| y1: | float8 |
| x2: | float8 |
| y2: | float8 |
SELECT source, target, cost FROM edge_table;
SELECT id, source, target, cost FROM edge_table;
SELECT id, source, target, cost, x1, y1, x2, y2 ,reverse_cost FROM edge_table
When the edge table has a different name to represent the required columns:
SELECT src as source, target, cost FROM othertable;
SELECT gid as id, src as source, target, cost FROM othertable;
SELECT gid as id, src as source, target, cost, fromX as x1, fromY as y1, toX as x2, toY as y2 ,Rcost as reverse_cost
FROM othertable;
The topology functions use the same names for id, source and target columns of the edge table, The fowllowing parameters have as default value:
| id: | int4 Default id |
|---|---|
| source: | int4 Default source |
| target: | int4 Default target |
| the_geom: | text Default the_geom |
| oneway: | text Default oneway |
| rows_where: | text Default true to indicate all rows (this is not a column) |
The following parameters do not have a default value and when used they have to be inserted in strict order:
| edge_table: | text |
|---|---|
| tolerance: | float8 |
| s_in_rules: | text[] |
| s_out_rules: | text[] |
| t_in_rules: | text[] |
| t_out_rules: | text[] |
When the columns required have the default names this can be used (pgr_func is to represent a topology function)
pgr_func('edge_table') -- when tolerance is not required
pgr_func('edge_table',0.001) -- when tolerance is required
-- s_in_rule, s_out_rule, st_in_rules, t_out_rules are required
SELECT pgr_analyzeOneway('edge_table', ARRAY['', 'B', 'TF'], ARRAY['', 'B', 'FT'],
ARRAY['', 'B', 'FT'], ARRAY['', 'B', 'TF'])
When the columns required do not have the default names its strongly recomended to use the named notation.
pgr_func('othertable', id:='gid',source:='src',the_geom:='mygeom')
pgr_func('othertable',0.001,the_geom:='mygeom',id:='gid',source:='src')
SELECT pgr_analyzeOneway('othertable', ARRAY['', 'B', 'TF'], ARRAY['', 'B', 'FT'],
ARRAY['', 'B', 'FT'], ARRAY['', 'B', 'TF']
source:='src',oneway:='dir')