Tablestore:Retrieve a Lastpoint index

1. Create a search index

The following sample code provides an example on how to create a search index for a Lastpoint index. For information about the sample scenario and data, see Appendix.

private static void createSearchIndex(SyncClient client) {
    CreateSearchIndexRequest createSearchIndexRequest = new CreateSearchIndexRequest();
    createSearchIndexRequest.setTableName("");
    createSearchIndexRequest.setIndexName("");
    IndexSchema indexSchema = new IndexSchema();
    indexSchema.setFieldSchemas(Arrays.asList(
            new FieldSchema("_#h", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("_m_name", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("_data_source", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("_tags", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true).setIsArray(true),
            new FieldSchema("_time", FieldType.LONG).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("gps", FieldType.GEO_POINT).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("speed", FieldType.DOUBLE).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("status", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("total_mileage", FieldType.DOUBLE).setIndex(true).setEnableSortAndAgg(true),
            new FieldSchema("remaining_mileage", FieldType.DOUBLE).setIndex(true).setEnableSortAndAgg(true)
    ));
    createSearchIndexRequest.setIndexSchema(indexSchema);
    client.createSearchIndex(createSearchIndexRequest);
}

2. Retrieve data by using a search index

The following sample code provides an example on how to use the range query feature of search indexes.

In this example, a search index is used to retrieve the rows in which the value of the speed field is greater than 20.0 in a Lastpoint index.

private static void rangeQuery(SyncClient client) {
    SearchQuery searchQuery = new SearchQuery();
    RangeQuery rangeQuery = new RangeQuery(); // Set the query type to RangeQuery.
    rangeQuery.setFieldName("speed");  // Specify the field to match.
    rangeQuery.greaterThan(ColumnValue.fromDouble(20.0));  // Specify the query condition for the field. Only rows in which the value of the field is greater than 20.0 meet the query condition.
    searchQuery.setGetTotalCount(true);
    searchQuery.setQuery(rangeQuery);
    // Specify that the rows that meet the query condition is sorted by the speed column in descending order.
    FieldSort fieldSort = new FieldSort("speed");
    fieldSort.setOrder(SortOrder.DESC);
    searchQuery.setSort(new Sort(Arrays.asList((Sort.Sorter)fieldSort)));
    searchQuery.setGetTotalCount(true); // Specify that the total number of rows that meet the query condition is returned.

    SearchRequest searchRequest = new SearchRequest("", "", searchQuery);
    // You can configure the columnsToGet parameter to specify the columns that you want to return or specify that all columns are returned. If you do not configure this parameter, only the primary key columns are returned.
    SearchRequest.ColumnsToGet columnsToGet = new SearchRequest.ColumnsToGet();
    columnsToGet.setReturnAll(true); // Specify that all columns are returned.
    searchRequest.setColumnsToGet(columnsToGet);

    SearchResponse resp = client.search(searchRequest);
    System.out.println("TotalCount: " + resp.getTotalCount()); // Print the total number of matched rows, not the number of returned rows.
    System.out.println("Row: " + resp.getRows());
}

FAQ

• What do I do if no data can be found by calling the Search operation?

• How do I increase the value of the limit parameter to 1000 when I call the Search operation of the search index feature to query data?

• Why does a token become invalid when pagination is used in a search index-based query?