CreateTopology
Name
CreateTopology — Creates a new topology schema and registers it in the topology.topology table.
Synopsis
integer
CreateTopology
(
varchar
topology_schema_name
)
;
integer
CreateTopology
(
varchar
topology_schema_name
, integer
srid
)
;
integer
CreateTopology
(
varchar
topology_schema_name
, integer
srid
, double precision
prec
)
;
integer
CreateTopology
(
varchar
topology_schema_name
, integer
srid
, double precision
prec
, boolean
hasz
)
;
Description
Creates a new topology schema with name
topology_name
and registers it in the
topology.topology
table.
Topologies must be uniquely named.
The topology tables (
edge_data
,
face
,
node
,and
relation
are created in the schema.
It returns the id of the topology.
The
srid
is the
spatial reference system
SRID for the topology.
The tolerance
prec
is measured in the units of the spatial reference system.
The tolerance defaults to 0.
hasz
defaults to false if not specified.
This is similar to the SQL/MM ST_InitTopoGeo but has more functionality.
Availability: 1.1
Enhanced: 2.0 added the signature accepting hasZ
Examples
Create a topology schema called
ma_topo
that stores edges and nodes in Massachusetts State Plane-meters (SRID = 26986).
The tolerance represents 0.5 meters since the spatial reference system is meter-based.
SELECT topology.CreateTopology('ma_topo', 26986, 0.5);
Create a topology for Rhode Island called
ri_topo
in spatial reference system State Plane-feet (SRID = 3438)
SELECT topology.CreateTopology('ri_topo', 3438) AS topoid;
topoid
------
2