PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual126 / 310ExamplesSELECT ST_AsEWKT(ST_ForceRHR(’POLYGON((0 0 2, 5 0 2, 0 5 2, 0 0 2),(1 1 2, 1 3 2, 3 1 2, 1 1 2))’));st_asewkt--------------------------------------------------------------POLYGON((0 0 2,0 5 2,5 0 2,0 0 2),(1 1 2,3 1 2,1 3 2,1 1 2))(1 row)See AlsoST_BuildArea, ST_Polygonize, ST_Reverse7.5.10 ST_LineMergeST_LineMerge — Returns a (set of) LineString(s) formed by sewing together a MULTILINESTRING.Synopsisgeometry ST_LineMerge(geometry amultilinestring);DescriptionReturns a (set of) LineString(s) formed by sewing together the constituent line work of a MULTILINESTRING.NoteOnly use with MULTILINESTRING/LINESTRINGs. If you feed a polygon or geometry collection into this function, it willreturn an empty GEOMETRYCOLLECTIONAvailability: 1.1.0Noterequires GEOS >= 2.1.0ExamplesSELECT ST_AsText(ST_LineMerge(ST_GeomFromText(’MULTILINESTRING((-29 -27,-30 -29.7,-36 -31,-45 -33),(-45 -33,-46 -32))’)));st_astext-------------------------------------------------------------------------------------------------- ←LINESTRING(-29 -27,-30 -29.7,-36 -31,-45 -33,-46 -32)(1 row)