Question

现在有这样一个需求，iserver通过工作空间发布了地图服务和数据服务，然后在前端绘制数据（点和线，几十万级别），而iclassic可以通过地图服务或者数据服务得到相应的数据，请问这两种方式，那种效率高？

第一种，通过地图服务得到要素数据

var host = window.isLocal ? window.server : "https://iserver.supermap.io",
var url = host + "/iserver/services/map-world/rest/maps/World";    
var queryParam, queryBySQLParams, queryBySQLService;
        queryParam = new SuperMap.REST.FilterParameter({
            name: "Capitals@World.1"
        });
        queryBySQLParams = new SuperMap.REST.QueryBySQLParameters({
            queryParams: [queryParam]
        });
        queryBySQLService = new SuperMap.REST.QueryBySQLService(url, {
            eventListeners: {"processCompleted": processCompleted, "processFailed": processFailed}
        });
        queryBySQLService.processAsync(queryBySQLParams);

第二种，通过数据服务得到要素数据

    var host = window.isLocal ? window.server : "https://iserver.supermap.io",
      var  url = host + "/iserver/services/data-jingjin/rest/data";        
var getFeatureParam, getFeatureBySQLService, getFeatureBySQLParams;

        getFeatureParam = new SuperMap.REST.FilterParameter({
            name: "Jingjin",
            attributeFilter: "SMID > -1"
        });
        getFeatureBySQLParams = new SuperMap.REST.GetFeaturesBySQLParameters({
            queryParameter: getFeatureParam,
            toIndex: 500,
            datasetNames: ["Jingjin:BaseMap_R"]
        });
        getFeatureBySQLService = new SuperMap.REST.GetFeaturesBySQLService(url, {
            eventListeners: {"processCompleted": processCompleted, "processFailed": processFailed}
        });

        getFeatureBySQLService.processAsync(getFeatureBySQLParams);

Answer 1

两个的查询效率相差不大，但是如果有专门的数据查询的需求建议还是走数据服务