pgr_createVerticesTable

pgr_createVerticesTable — Reconstructs the vertices table based on the source and target information.

Availability

• Version 2.0.0

  • Renamed from version 1.x

  • Official function

Description

The function returns:

• OK after the vertices table has been reconstructed.

• FAIL when the vertices table was not reconstructed due to an error.

Signatures

pgr_createVerticesTable(edge_table, [the_geom, source, target, rows_where])

RETURNS VARCHAR

Parameters

The reconstruction of the vertices table function accepts the following parameters:

edge_table:

text Network table name. (may contain the schema name as well)

the_geom:

text Geometry column name of the network table. Default value is the_geom.

source:

text Source column name of the network table. Default value is source.

target:

text Target column name of the network table. Default value is target.

rows_where:

text Condition to SELECT a subset or rows. Default value is true to indicate all rows.

Warning

The edge_table will be affected

• An index will be created, if it doesn’t exists, to speed up the process to the following columns:

  • the_geom

  • source

  • target

The function returns:

• OK after the vertices table has been reconstructed.

  • Creates a vertices table: <edge_table>_vertices_pgr.

  • Fills id and the_geom columns of the vertices table based on the source and target columns of the edge table.

• FAIL when the vertices table was not reconstructed due to an error.

  • A required column of the Network table is not found or is not of the appropriate type.

  • The condition is not well formed.

  • The names of source, target are the same.

  • The SRID of the geometry could not be determined.

The Vertices Table

The vertices table is a requierment of the pgr_analyzeGraph and the pgr_analyzeOneWay functions.

The structure of the vertices table is:

id:

bigint Identifier of the vertex.

cnt:

integer Number of vertices in the edge_table that reference this vertex. See pgr_analyzeGraph.

chk:

integer Indicator that the vertex might have a problem. See pgr_analyzeGraph.

ein:

integer Number of vertices in the edge_table that reference this vertex as incoming. See pgr_analyzeOneWay.

eout:

integer Number of vertices in the edge_table that reference this vertex as outgoing. See pgr_analyzeOneWay.

the_geom:

geometry Point geometry of the vertex.

Example 1:

The simplest way to use pgr_createVerticesTable

SELECT  pgr_createVerticesTable('edges', 'geom');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Additional Examples

Example 2:

When the arguments are given in the order described in the parameters:

SELECT  pgr_createVerticesTable('edges', 'geom', 'source', 'target');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

We get the same result as the simplest way to use the function.

Warning

An error would occur when the arguments are not given in the appropriate order: In this example, the column source column source of the table mytable is passed to the function as the geometry column, and the geometry column the_geom is passed to the function as the source column.

SELECT  pgr_createVerticesTable('edges', 'source', 'geom', 'target');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','source','geom','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  ----> PGR ERROR in pgr_createVerticesTable: Wrong type of Column source: geom
HINT:    ----> Expected type of geom is integer, smallint or bigint but USER-DEFINED was found
NOTICE:  Unexpected error raise_exception
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

When using the named notation

Example 3:

The order of the parameters do not matter:

SELECT  pgr_createVerticesTable('edges', the_geom:='geom', source:='source', target:='target');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 4:

Using a different ordering

SELECT  pgr_createVerticesTable('edges', source:='source', target:='target', the_geom:='geom');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 5:

Parameters defined with a default value can be omitted, as long as the value matches the default:

SELECT  pgr_createVerticesTable('edges', 'geom', source:='source');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Selecting rows using rows_where parameter

Example 6:

Selecting rows based on the id.

SELECT  pgr_createVerticesTable('edges', 'geom', rows_where:='id < 10');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','id < 10')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  9 VERTICES
NOTICE:                                         FOR   10  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 10
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 7:

Selecting the rows where the geometry is near the geometry of row with id =5 .

SELECT  pgr_createVerticesTable('edges', 'geom',
    rows_where:='geom && (select st_buffer(geom,0.5) FROM edges WHERE id=5)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','geom && (select st_buffer(geom,0.5) FROM edges WHERE id=5)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  9 VERTICES
NOTICE:                                         FOR   9  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 9
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 8:

Selecting the rows where the geometry is near the geometry of the row with gid =100 of the table othertable.

DROP TABLE IF EXISTS otherTable;
NOTICE:  table "othertable" does not exist, skipping
DROP TABLE
CREATE TABLE otherTable AS  (SELECT 100 AS gid, st_point(2.5,2.5) AS other_geom) ;
SELECT 1
SELECT  pgr_createVerticesTable('edges', 'geom',
    rows_where:='geom && (select st_buffer(other_geom,0.5) FROM otherTable WHERE gid=100)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('edges','geom','source','target','geom && (select st_buffer(other_geom,0.5) FROM otherTable WHERE gid=100)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.edges_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  10 VERTICES
NOTICE:                                         FOR   12  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 12
NOTICE:  Vertices table for table public.edges is: public.edges_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Usage when the edge table’s columns DO NOT MATCH the default values:

Using the following table

DROP TABLE IF EXISTS mytable;
NOTICE:  table "mytable" does not exist, skipping
DROP TABLE
CREATE TABLE mytable AS (SELECT id AS gid, geom AS mygeom, source AS src ,target AS tgt FROM edges) ;
SELECT 18

Using positional notation:

Example 9:

The arguments need to be given in the order described in the parameters:

SELECT  pgr_createVerticesTable('mytable', 'mygeom', 'src', 'tgt');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.mytable_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.mytable is: public.mytable_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Warning

An error would occur when the arguments are not given in the appropriate order: In this example, the column src of the table mytable is passed to the function as the geometry column, and the geometry column mygeom is passed to the function as the source column.

SELECT  pgr_createVerticesTable('mytable', 'src', 'mygeom', 'tgt');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','src','mygeom','tgt','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  ----> PGR ERROR in pgr_createVerticesTable: Wrong type of Column source: mygeom
HINT:    ----> Expected type of mygeom is integer, smallint or bigint but USER-DEFINED was found
NOTICE:  Unexpected error raise_exception
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

When using the named notation

Example 10:

The order of the parameters do not matter:

SELECT  pgr_createVerticesTable('mytable',the_geom:='mygeom',source:='src',target:='tgt');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.mytable_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.mytable is: public.mytable_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 11:

Using a different ordering

In this scenario omitting a parameter would create an error because the default values for the column names do not match the column names of the table.

SELECT  pgr_createVerticesTable(
    'mytable', source:='src', target:='tgt',
    the_geom:='mygeom');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','true')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.mytable_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  17 VERTICES
NOTICE:                                         FOR   18  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 18
NOTICE:  Vertices table for table public.mytable is: public.mytable_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Selecting rows using rows_where parameter

Example 12:

Selecting rows based on the gid. (positional notation)

SELECT  pgr_createVerticesTable(
    'mytable', 'mygeom', 'src', 'tgt',
    rows_where:='gid < 10');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','gid < 10')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.mytable_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  9 VERTICES
NOTICE:                                         FOR   10  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 10
NOTICE:  Vertices table for table public.mytable is: public.mytable_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 13:

Selecting rows based on the gid. (named notation)

SELECT  pgr_createVerticesTable(
    'mytable', source:='src', target:='tgt', the_geom:='mygeom',
    rows_where:='gid < 10');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','gid < 10')
NOTICE:  Performing checks, please wait .....
NOTICE:  Populating public.mytable_vertices_pgr, please wait...
NOTICE:    ----->   VERTICES TABLE CREATED WITH  9 VERTICES
NOTICE:                                         FOR   10  EDGES
NOTICE:    Edges with NULL geometry,source or target: 0
NOTICE:                              Edges processed: 10
NOTICE:  Vertices table for table public.mytable is: public.mytable_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createverticestable
-------------------------
 OK
(1 row)

Example 14:

Selecting the rows where the geometry is near the geometry of row with gid = 5.

SELECT  pgr_createVerticesTable(
    'mytable', 'mygeom', 'src', 'tgt',
    rows_where := 'the_geom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE gid=5)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','the_geom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE gid=5)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Got column "the_geom" does not exist
NOTICE:  ERROR: Condition is not correct, please execute the following query to test your condition
NOTICE:  select * from public.mytable WHERE true AND (the_geom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE gid=5)) limit 1
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

Example 15:

TBD

SELECT  pgr_createVerticesTable(
    'mytable', source:='src', target:='tgt', the_geom:='mygeom',
    rows_where:='mygeom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE id=5)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','mygeom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE id=5)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Got column "id" does not exist
NOTICE:  ERROR: Condition is not correct, please execute the following query to test your condition
NOTICE:  select * from public.mytable WHERE true AND (mygeom && (SELECT st_buffer(mygeom,0.5) FROM mytable WHERE id=5)) limit 1
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

Example 16:

Selecting the rows where the geometry is near the geometry of the row with gid =100 of the table othertable.

DROP TABLE IF EXISTS otherTable;
DROP TABLE
CREATE TABLE otherTable AS  (SELECT 100 AS gid, st_point(2.5,2.5) AS other_geom) ;
SELECT 1

SELECT pgr_createVerticesTable(
    'mytable', 'mygeom', 'src', 'tgt',
    rows_where:='the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Got column "the_geom" does not exist
NOTICE:  ERROR: Condition is not correct, please execute the following query to test your condition
NOTICE:  select * from public.mytable WHERE true AND (the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)) limit 1
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

Example 17:

TBD

SELECT  pgr_createVerticesTable(
    'mytable',source:='src',target:='tgt',the_geom:='mygeom',
    rows_where:='the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)');
NOTICE:  PROCESSING:
NOTICE:  pgr_createVerticesTable('mytable','mygeom','src','tgt','the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)')
NOTICE:  Performing checks, please wait .....
NOTICE:  Got column "the_geom" does not exist
NOTICE:  ERROR: Condition is not correct, please execute the following query to test your condition
NOTICE:  select * from public.mytable WHERE true AND (the_geom && (SELECT st_buffer(othergeom,0.5) FROM otherTable WHERE gid=100)) limit 1
 pgr_createverticestable
-------------------------
 FAIL
(1 row)

The example uses the Sample Data network.

See Also

• Topology - Family of Functions for an overview of a topology for routing algorithms.

• pgr_createTopology <pgr_create_topology>` to create a topology based on the geometry.

• pgr_analyzeGraph to analyze the edges and vertices of the edge table.

• pgr_analyzeOneWay to analyze directionality of the edges.

Indices and tables

• Index

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