CreateTopology — Creates a new topology schema and registers it in the topology.topology table.
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
Creates a new topology schema with name
and registers it in the
Topologies must be uniquely named.
The topology tables (
relation are created in the schema.
It returns the id of the topology.
srid is the spatial reference system SRID for the topology.
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.
Enhanced: 2.0 added the signature accepting hasZ
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