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:

id:ANY-INTEGER identifier of the edge.
source:ANY-INTEGER identifier of the first end point vertex of the edge.
target:ANY-INTEGER identifier of the second end pont vertex of the edge.
cost:ANY-NUMERICAL weight of the edge (source, target), if negative: edge (source, target) does not exist, therefore it’s not part of the graph.
reverse_cost:ANY-NUMERICAL (optional) weight of the edge (target, source), if negative: edge (target, source) does not exist, therefore it’s not part of the graph.

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 requiered
pgr_func('edge_table',0.001)  -- when tolerance is requiered
-- s_in_rule, s_out_rule, st_in_rules, t_out_rules are requiered
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')