MongoDB学习之五----空间操作

     MongoDB采用geoJson格式来存储常见的点,线,面的几何信息.

     点:db.points.insert({"pt":{type:"Point",coordinates:[10,10]}})

     线:db.lines.insert({"ln":{type:"LineString",coordinates:[[10,10],[20,20]]}})

     面:db.polygons.insert({"pg":{type:"Polygon",coordinates:[[[5,5],[5,15],[15,15],[15,5],[5,5]]]}})

    

     常见的空间查找操作:

     1.包含$geoWithin

        db.points.find({"pt":{$geoWithin:{$geometry:{type:"Polygon",coordinates:[[[5,5],[5,15],[15,15],[15,5],[5,5]]]}}}})  

        圆形查询:  db.points.find({"pt":{$geoWithin:{$centerSphere:[[6,6](圆心),2(半径)]}}) 

     2.相交$geoIntersects

         db.lines.find({"ln":{$geoIntersects:{$geometry:{type:"Polygon",coordinates:[[[5,5],[5,15],[15,15],[15,5],[5,5]]]}}}}) 

     3.点查询$near

        先给查询的字段建立一个2dsphere索引:db.points.ensureIndex({"pt":"2dsphere"})

        执行周边查询:

          db.points.find({"pt":{$near:{$geometry:{type:"Point",coordinates:[5.01,5.01]},$maxDistance:1000000(米)}}})

     4.周边查询geonear

         先要建立空间索引,再执行周边查询:

         db.runCommand({geoNear:"points",near:{type:"Point",coordinates:[5.01,5.01]},spherical:true})