属性查询如何实现范围查询
1.属性查询中范围与空间查询范围的区别？
??? 属性查询中的范围是属于普通索引，几何查询中的范围查询属于空间索引（索引方式有三种：全文索引，普通索引，空间索引）
2.属性查询中的范围的filter的书写方式是var lon = new Geo.Filter.Comparison({
??????????? type: OpenLayers.Filter.Comparison.BETWEEN,//关系运算
??????????? property: "x",//查询字段
??????????? lowerBoundary: bounds.left,
???upperBoundary: bounds.right
??????? });
?? var lat = new Geo.Filter.Comparison({
??????????? type: OpenLayers.Filter.Comparison.BETWEEN,//关系运算
??????????? property: "y",//查询字段
??????????? lowerBoundary: bounds.bottom,
???upperBoundary: bounds.top
??????? });
??????? var boundsFilter = new Geo.Filter.Logical({
??????????? type: Geo.Filter.Logical.AND,
??????????? filters: [lon,lat]
??????? });
?
说明：普通索引实现的范围查询比空间索引要快
