1、基于PostGIS的空間數(shù)據(jù)實(shí)時(shí)編輯與拓?fù)錂z查CONTENTS 目錄PART ONE 實(shí)時(shí)編輯PART TWO 空間拓?fù)?10203PART THREE 拓展01數(shù)據(jù)編輯與問題優(yōu)化C/S數(shù)據(jù)編輯用戶GIS軟件SHP、GDBGeoJSON用戶瀏覽器服務(wù)端DBDBDBSHP、GDBGeoJSONB/S數(shù)據(jù)編輯數(shù)據(jù)操 作ST_SplitThe function supports splitting a line by (multi)point, (multi)line or (multi)polygon boundary, a (multi)polygon by line. The returned

2、 geometry is always a collection.Think of this function as the opposite of ST_Union.Theoretically applying ST_Union to the elements of the returned collection should always yield the original geometry.切割前切割后ST_UnionOutput type can be a MULTI*, single geometry, or Geometry Collection. Comes in 2 vari

3、ants. Variant 1 unions 2 geometries resulting in a new geometry with no intersecting regions.Variant 2 is an aggregate function that takes a set of geometries and unions them into a single ST_Geometry resulting in no intersecting regions.合并前合并后成功了 ？存在問題：切割后合并存在短線問題：ST_Buffer(geometry g1, float radiu

4、s_of_buffer, text buffer_style_parameters=)優(yōu)化方案優(yōu)化方案：ST_Snap(geometry input, geometry reference, float tolerance)ST_Buffergeometry ST_Buffer(geometry g1, float radius_of_buffer, text buffer_style_parameters=);geometry ST_Buffer(geometry g1, float radius_of_buffer, integer num_seg_quarter_circle);ST_B

5、uffergeometry ST_Buffer(geometry g1, float radius_of_buffer, text buffer_style_parameters=);geometry ST_Buffer(geometry g1, float radius_of_buffer, integer num_seg_quarter_circle);ST_Snapgeometry ST_Snap(geometry input, geometry reference, float tolerance);Snaps the vertices and segments of a geomet

6、ry to another Geometrys vertices. A snap distance tolerance is used to control where snapping is performed. The result geometry is the input geometry with the vertices snapped. If no snapping occurs then the input geometry is returned unchanged.Snapping one geometry to another can improve robustness

7、 for overlay operations by eliminating nearly-coincident edges (which cause problems during noding and intersection calculation).ST_SnapgeometryST_Snap(geometry input, geometry reference, float tolerance);ST_SnapgeometryST_Snap(geometry input, geometry reference, float tolerance);ST_SnapgeometryST_S

8、nap(geometry input, geometry reference, float tolerance);Note：ST_Buffer與ST_Snap的閾值大小正負(fù)值ST_Buffer處理后圖形的有效性驗(yàn)證問題（ST_IsValid）02數(shù)據(jù)拓?fù)渑c問題優(yōu)化哪些拓?fù)鋯栴}？超出邊界面縫隙面重疊取相交部分：St_Intersection判斷是否相交：St_IntersectsbooleanST_Intersects( geometry geomA , geometry geomB )SELECT ST_Intersects(POINT(0 0):geometry, LINESTRING (

9、2 0, 0 2 ):geometry); - fgeometryST_Intersection( geometry geomA , geometry geomB );SELECT ST_AsText(ST_Intersection(POINT(0 0):geometry, LINESTRING ( 0 0, 0 2 ):geometry); - POINT(0 0)取不相交部分： ST_SymDifferencegeometryST_SymDifference(geometry geomA, geometry geomB);SELECT ST_AsText( ST_SymDifference

10、( ST_GeomFromText(LINESTRING(50 100, 50 200),ST_GeomFromText(LINESTRING(50 50, 50 150) ) ); st_astext - MULTILINESTRING(50 150,50 200),(50 50,50 100)從A取與B不相交部分： ST_DifferencegeometryST_Difference(geometry geomA, geometry geomB);SELECT ST_AsText( ST_Difference( LINESTRING(50 100,50 200):geometry, LIN

11、ESTRING(50 50, 50 150):geometry ) ); st_astext - LINESTRING(50 150,50 200)如何實(shí)現(xiàn)？超出邊界將內(nèi)部面Union，命名為geom1外部大面命名為geom2ST_Difference（geom1，geom2）如何實(shí)現(xiàn)？面縫隙將內(nèi)部面Union，命名為geom1外部大面命名為geom2ST_SymDifference（geom1，geom2如何實(shí)現(xiàn)？面重疊1.St_Intersection（geom1，geom2）成功了 ？存在問題：拓?fù)錂z查后出現(xiàn)很多小面：ST_Buffer(geometry g1, float radius

12、_of_buffer, text buffer_style_parameters=)優(yōu)化方案優(yōu)化方案：設(shè)置拓?fù)浜蟪霈F(xiàn)結(jié)果的面積閾值Note：正負(fù)值ST_Buffer處理后圖形的有效性驗(yàn)證問題（ST_IsValid， st_makeValid）相 交 后 結(jié) 果 是 否 為 面 ， 提 取 對(duì) 應(yīng) 類 型 的 圖 形 （ ST_CollectionExtract ）SRID丟失（ST_SetSrid）應(yīng)用案例：第四次全國(guó)經(jīng)濟(jì)普查用戶：5W*4村：66W小區(qū)：90W應(yīng)用案例：第四次全國(guó)體育場(chǎng)地調(diào)查調(diào)查員用戶：13W平臺(tái)端用戶：3000體育場(chǎng)地：300W場(chǎng)地管理單位：130W 調(diào)查員定位：950W應(yīng)用案例：第七次全國(guó)人口普查03 拓展介紹ST_AsMvtST_AsMVTGeomgeometry ST_AsMVTGeom(geometry geom, box2d bounds, integer extent=4096, integer buffer=256, boolean clip_geom=true);bytea ST_AsMVT(anyelement row, text name, integer e