mysql存储字段类型 :

• Geometry
  Geometry是几何对象的基类, 也就是说Point, LineString, Polygon都是Geometry的子类,

• Point
  点对象, 有一个坐标值，没有长度、面积、边界。
  数据格式为『经度(longitude)在前，维度(latitude)在后，用空格分隔』 例: POINT(121.213342 31.234532)

• LineString
  线对象, 由一系列点连接而成。
  如果线从头至尾没有交叉，那就是简单的（simple）
  如果起点和终点重叠，那就是封闭的（closed）
  数据格式为『点与点之间用逗号分隔；一个点中的经纬度用空格分隔，与POINT格式一致』例：LINESTRING(121.342423 31.542423,121.345664 31.246790,121.453178 31.456862)

• Polygon
  多边形对象。可以是一个实心平面形，即没有内部边界，也可以有空洞，类似纽扣
  数据格式为
  『实心型: 一个表示外部边界的LineString和0个表示内部边界的LineString组成』例:
  POLYGON((121.342423 31.542423,121.345664 31.246790,121.453178 31.456862),(121.563633 31.566652,121.233565 31.234565,121.568756 31.454367))
  『纽扣型: 一个表示外部边界的LineString和多个表示内部边界的LineString组成』例: POLYGON((0 0,10 0, 10 10, 0 10))

• MultiPoint, MultiLineString, MultiPolygon, GeometryCollection
  为以上对象的集合。
  数据格式为下例
  MULTIPOINT(0 0, 20 20, 60 60)
  MULTILINESTRING((10 10, 20 20), (15 15, 30 15))
  MULTIPOLYGON(((0 0,10 0,10 10,0 10,0 0)),((5 5,7 5,7 7,5 7, 5 5)))
  GEOMETRYCOLLECTION(POINT(10 10), POINT(30 30), LINESTRING(15 15, 20 20))

常用函数 :

一、几何对象属性查询函数:

Geometry(为基类函数, 点线面都可用)

1. Dimension(g) : 返回几何对象g的维数, 点为0, 线为1, 多边形为2
2. Envelope(g): 返回几何对象g的最小边界矩形(xy的极值点)。如果对象为点则返回该点对象，如果对象为线和多边形则返回极值xy坐标构造成的矩形Polygon
3. GeometryType(g): 返回几何对象g的类型名称, 点为POINT, 线为LINEPOINT, 多边形为POLYGON
4. IsClosed(g): 返回几何对象g是否封闭 ,条件为该线对象首尾point重合则为封闭, 封闭为1, 不封闭为0, 如果几何对象不为线对象的话, 返回为null
5. IsSimple(g): 返回几何对象g是否简单, 条件为该线对象路径没有交叉则为简单, 简单为1, 不简单为0, 如果几何对象不为线对象的话, 返回为null

Point

1. X(p): 返回该点X坐标
2. Y(p): 返回改点Y坐标

LineString

1. EndPoint(line): 返回对象line的最后一个点Point
2. StartPoint(line): 返回对象line的第一个点Point
3. PointN(line, N): 返回对象line中第N个点，N从1开始

Polygon

1. ExteriorRing(poly): 返回多边形对象poly的外轮廓线，类型为LineString
2. InteriorRingN(poly, N): 返回对象poly的第N个空洞轮廓线，N从1开始
3. NumInteriorRings(poly): 返回对象poly的空洞个数

二、返回新的几何对象

1. st_union(g1, g2): 返回 面1和面2的并集
2. st_difference(g1, g2): 返回 面1 - (面1和面2的交集)
3. st_intersection(g1, g2): 返回 面1和面2的交集

三、查询几何对象关系

1. ST_Contains(a,b): 如果几何对象a完全包含几何对象b, 则返回1, 否则0

   image

2. ST_Crosses(a,b): 如果a横跨b,则返回1,否则返回0

   image

3. ST_Disjoint(a,b): 如果a和b不相交,则返回1.否则返回0

   image

4. ST_Equals(a,b): 如果a和b有相同的几何描述,则返回1, 否则返回0; 例如一栋楼的两层xy坐标描述一致,所以返回为1

   image

5. ST_Intersects(a,b): 与ST_Disjoint结果完全相反

6. ST_Overlaps(a,b): 两个维度相同的几何对象相交的交集是一样维度的几何对象时, 返回1 , 否则返回0

7. ST_Touches(a,b): 几何对象a交且只交于b的边界时, 返回1, 否则0

   image

8. ST_Within(a,b): 与ST_Contains(a,b)结果完全相反

四、数值计算

1. ST_Distance_Sphere(POINT(30 40), POINT(20 30)):计算两点之间距离(千米)

五、描述语言转化成几何对象

1. geomfromtext(''): 空间函数中, 参数不可直接写空间描述格式, 需要用geomfromtext('')来将描述语言转化成函数的对象,例如, 要查找test表中, 所有和 POLYGON((4 4, 4 6, 6 6, 6 4,4 4)) 相交的多边形, 则sql写为select polygon1 from test where st_disjoint(geomfromtext('POLYGON((4 4, 4 6, 6 6, 6 4,4 4))'),polygon1) = 0

六、附：MySQL空间相关函数一览表

The following table lists each spatial function and provides a short description of each one.
Name | Description

1. Area() Return Polygon or MultiPolygon area
2. AsBinary(), AsWKB() Convert from internal geometry format to WKB
3. AsText(), AsWKT() Convert from internal geometry format to WKT
4. Buffer()Return geometry of points within given distance from geometry
5. Centroid() Return centroid as a point
6. Contains() Whether MBR of one geometry contains MBR of another
7. Crosses() Whether one geometry crosses another
8. Dimension() Dimension of geometry
9. Disjoint() Whether MBRs of two geometries are disjoint
10. EndPoint() End Point of LineString
11. Envelope() Return MBR of geometry
12. Equals() Whether MBRs of two geometries are equal
13. ExteriorRing()Return exterior ring of Polygon
14. GeomCollFromText(),GeometryCollectionFromText()Return geometry collection from WKT
15. GeomCollFromWKB(),GeometryCollectionFromWKB()Return geometry collection from WKB
16. GeometryCollection() Construct geometry collection from geometries
17. GeometryN() Return N-th geometry from geometry collection
18. GeometryType() Return name of geometry type
19. GeomFromText(),GeometryFromText()Return geometry from WKT
20. GeomFromWKB(),GeometryFromWKB()Return geometry from WKB
21. GLength() Return length of LineString
22. InteriorRingN() Return N-th interior ring of Polygon
23. Intersects() Whether MBRs of two geometries intersect
24. IsClosed() Whether a geometry is closed and simple
25. IsEmpty() Placeholder_function
26. IsSimple() Whether a geometry is simple
27. LineFromText(),LineStringFromText()Construct LineString from WKT
28. LineFromWKB(),LineStringFromWKB()Construct LineString from WKB
29. LineString() Construct LineString from Point values
30. MBRContains() Whether MBR of one geometry contains MBR of another
31. MBRDisjoint() Whether MBRs of two geometries are disjoint
32. MBREqual() Whether MBRs of two geometries are equal
33. MBRIntersects() Whether MBRs of two geometries intersect
34. MBROverlaps() Whether MBRs of two geometries overlap
35. MBRTouches() Whether MBRs of two geometries touch
36. MBRWithin() Whether MBR of one geometry is within MBR of another
37. MLineFromText(),MultiLineStringFromText()Construct MultiLineString from WKT
38. MLineFromWKB(),MultiLineStringFromWKB()Construct MultiLineString from WKB
39. MPointFromText(),MultiPointFromText()Construct MultiPoint from WKT
40. MPointFromWKB(),MultiPointFromWKB()Construct MultiPoint from WKB
41. MPolyFromText(),MultiPolygonFromText()Construct MultiPolygon from WKT
42. MPolyFromWKB(),MultiPolygonFromWKB()Construct MultiPolygon from WKB
43. MultiLineString() Contruct MultiLineString from LineString values
44. MultiPoint() Construct MultiPoint from Point values
45. MultiPolygon() Construct MultiPolygon from Polygon values
46. NumGeometries() Return number of geometries in geometry collection
47. NumInteriorRings() Return number of interior rings in Polygon
48. NumPoints() Return number of points in LineString
49. Overlaps() Whether MBRs of two geometries overlap
50. Point() Construct Point from coordinates
51. PointFromText() Construct Point from WKT
52. PointFromWKB() Construct Point from WKB
53. PointN() Return N-th point from LineString
54. PolyFromText(),PolygonFromText()Construct Polygon from WKT
55. PolyFromWKB(), PolygonFromWKB() Construct Polygon from WKB
56. Polygon() Construct Polygon from LineString arguments
57. SRID() Return spatial reference system ID for geometry
58. ST_Area() Return Polygon or MultiPolygon area
59. ST_AsBinary(), ST_AsWKB() Convert from internal geometry format to WKB
60. ST_AsText(), ST_AsWKT() Convert from internal geometry format to WKT
61. ST_Buffer() Return geometry of points within given distance from geometry
62. ST_Centroid() Return centroid as a point
63. ST_Contains() Whether one geometry contains another
64. ST_Crosses() Whether one geometry crosses another
65. ST_Difference() Return point set difference of two geometries
66. ST_Dimension() Dimension of geometry
67. ST_Disjoint() Whether one geometry is disjoint from another
68. ST_Distance() The distance of one geometry from another
69. ST_EndPoint() End Point of LineString
70. ST_Envelope() Return MBR of geometry
71. ST_Equals() Whether one geometry is equal to another
72. ST_ExteriorRing() Return exterior ring of Polygon
73. ST_GeomCollFromText(),ST_GeometryCollectionFromText(),ST_GeomCollFromTxt()Return geometry collection from WKT
74. ST_GeomCollFromWKB(),ST_GeometryCollectionFromWKB()Return geometry collection from WKB
75. ST_GeometryN() Return N-th geometry from geometry collection
76. ST_GeometryType() Return name of geometry type
77. ST_GeomFromText(),ST_GeometryFromText()Return geometry from WKT
78. ST_GeomFromWKB(),ST_GeometryFromWKB()Return geometry from WKB
79. ST_InteriorRingN() Return N-th interior ring of Polygon
80. ST_Intersection() Return point set intersection of two geometries
81. ST_Intersects() Whether one geometry intersects another
82. ST_IsClosed() Whether a geometry is closed and simple
83. ST_IsEmpty() Placeholder_function
84. ST_IsSimple() Whether a geometry is simple
85. ST_LineFromText(),ST_LineStringFromText()Construct LineString from WKT
86. ST_LineFromWKB(),ST_LineStringFromWKB()Construct LineString from WKB
87. ST_NumGeometries() Return number of geometries in geometry collection
88. ST_NumInteriorRing(),ST_NumInteriorRings()Return number of interior rings in Polygon
89. ST_NumPoints() Return number of points in LineString
90. ST_Overlaps() Whether one geometry overlaps another
91. ST_PointFromText() Construct Point from WKT
92. ST_PointFromWKB() Construct Point from WKB
93. ST_PointN() Return N-th point from LineString
94. ST_PolyFromText(),ST_PolygonFromText()Construct Polygon from WKT
95. ST_PolyFromWKB(),ST_PolygonFromWKB()Construct Polygon from WKB
96. ST_SRID() Return spatial reference system ID for geometry
97. ST_StartPoint() Start Point of LineString
98. ST_SymDifference() Return point set symmetric difference of two geometries
99. ST_Touches() Whether one geometry touches another
100. ST_Union() Return point set union of two geometries
101. ST_Within() Whether one geometry is within another
102. ST_X() Return X coordinate of Point
103. ST_Y() Return Y coordinate of Point
104. StartPoint() Start Point of LineString
105. Touches() Whether one geometry touches another
106. Within() Whether MBR of one geometry is within MBR of another
107. X() Return X coordinate of Point
108. Y() Return Y coordinate of Point

七、注意事项：

1、数据库中有geometry类型，但是很多语言中没有直接的geometry类型，以java为例，如果想要存储geometry字段，需要增加SET @g1 = geomFromText(geometry) 将字符串转换成几何对象存储；同样，从数据库中直接取出的geometry类型字段，java无法使用，需要在数据库中查询的时候，做个几何类型转字符串类型的处理：select astext(geometry_info) as geometryInfo

八、参考资料：

1.mysql存储与计算地理位置信息
2.ArcGis Desktop