A terms query is similar to a term query. A terms query supports multiple terms. A row of data is returned if at least one of the keywords matches the column value. Terms queries can be used in the same manner as the IN operator in SQL statements.
Prerequisites
An OTSClient instance is initialized. For more information, see Initialize an OTSClient instance.
A data table is created and data is written to the data table. For more information, see Create a data table and Write data.
A search index is created for the data table. For more information, see Create a search index.
Parameters
Parameter | Description |
query | The type of the query. Set the query parameter to TermsQuery. |
fieldName | The name of the field that you want to match. |
terms | The keywords that are used to match the value of the field when you perform a terms query. You can specify up to 1,024 keywords. A row of data is returned when the column value matches at least one of the keywords. |
getTotalCount | Specifies whether to return the total number of rows that meet the query conditions. The default value of this parameter is false, which specifies that the total number of rows that meet the query conditions is not returned. If you set this parameter to true, the query performance is compromised. |
weight | The weight that you want to assign to the field that you want to query to calculate the BM25-based keyword relevance score. This parameter is used in full-text search scenarios. If you specify a higher weight for the field that you want to query, the BM25-based keyword relevance score for the field is higher. The value of this parameter is a positive floating point number. This parameter does not affect the number of rows that are returned. However, this parameter affects the BM25-based keyword relevance scores of the query results. |
tableName | The name of the data table. |
indexName | The name of the search index. |
columnsToGet | Specifies whether to return all columns of each row that meets the query conditions. You can specify the returnAll and columns fields for this parameter. The default value of the returnAll field is false, which specifies that not all columns are returned. In this case, you can use the columns field to specify the columns that you want to return. If you do not specify the columns that you want to return, only the primary key columns are returned. If you set the returnAll field to true, all columns are returned. |
Example
The following sample code provides an example on how to query the rows in which the value of the Col_Keyword column is "hangzhou" or "xi'an":
/**
* Search the table for rows in which the value of Col_Keyword is "hangzhou" or "xi'an".
* @param client
*/
private static void termQuery(SyncClient client) {
SearchQuery searchQuery = new SearchQuery();
TermsQuery termsQuery = new TermsQuery(); // Set the query type to TermsQuery.
termsQuery.setFieldName("Col_Keyword"); // Specify the name of the column that you want to match.
termsQuery.addTerm(ColumnValue.fromString("hangzhou")); // Specify the keyword that you want to match.
termsQuery.addTerm(ColumnValue.fromString("xi'an")); // Specify the keyword that you want to match.
searchQuery.setQuery(termsQuery);
//searchQuery.setGetTotalCount(true); //Set the GetTotalCount parameter to true to return the total number of rows that meet the query conditions.
SearchRequest searchRequest = new SearchRequest("<TABLE_NAME>", "<SEARCH_INDEX_NAME>", searchQuery);
// You can use the columnsToGet parameter to specify the columns that you want to return or specify that all columns are returned. If you do not specify this parameter, only the primary key columns are returned.
//SearchRequest.ColumnsToGet columnsToGet = new SearchRequest.ColumnsToGet();
//columnsToGet.setReturnAll(true); // Set the ReturnAll parameter to true to return all columns.
//columnsToGet.setColumns(Arrays.asList("ColName1","ColName2")); // Specify the columns that you want to return.
//searchRequest.setColumnsToGet(columnsToGet);
SearchResponse resp = client.search(searchRequest);
//System.out.println("TotalCount: " + resp.getTotalCount()); // Specify that the total number of rows that meet the query conditions instead of the number of returned rows is displayed.
System.out.println("Row: " + resp.getRows());
}
FAQ
References
When you use a search index to query data, you can use the following query methods: term query, terms query, match all query, match query, match phrase query, prefix query, range query, wildcard query, geo query, KNN vector query, Boolean query, nested query, and exists query. After you create a search index, you can use the query methods provided by the search index to query data from multiple dimensions based on your business requirements.
You can sort or paginate rows that meet the query conditions by using the sorting and paging features. For more information, see Perform sorting and paging.
You can use the collapse (distinct) feature to collapse the result set based on a specific column. This way, data of the specified type appears only once in the query results. For more information, see Collapse (distinct).
If you want to analyze data in a table, you can call the Search operation to use the aggregation feature or use the SQL query feature. For example, you can query the maximum and minimum values, the sum of the values, and the number of rows. For more information, see Aggregation and SQL query.
If you want to obtain all rows that meet the query conditions without the need to sort the rows, you can call the ParallelScan and ComputeSplits operations to use the parallel scan feature. For more information, see Parallel scan.