A match phrase query is similar to match query, except that a match phrase query evaluates the positions of tokens. A row meets the query condition only when the order and positions of the tokens in the row match the order and positions of the tokens that are contained in the keyword. If the tokenization method for the column that you want to query is fuzzy tokenization, match phrase query is performed at a lower latency than wildcard query.
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 |
fieldName | The name of the field that you want to match. You can perform match phrase queries on TEXT fields. |
text | The keyword that is used to match the value of the field when you perform a match phrase query. If the field that you want to match is a TEXT field, the keyword is tokenized into multiple tokens based on the analyzer type that you specify when you create the search index. If you do not specify the analyzer type when you create the search index, single-word tokenization is performed. For more information, see Tokenization. For example, if you perform a match phrase query by using the phrase "this is", "..., this is tablestore" and "this is a table" are returned. "this table is ..." or "is this a table" is not returned. |
query | The type of the query. Set the query parameter to matchPhraseQuery. |
offset | The position from which the current query starts. |
limit | The maximum number of rows that you want the current query to return. To query only the number of rows that meet the query conditions without specific data, set the limit parameter to 0. |
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 the columnsToGet 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. |
Sample code
The following sample code provides an example on how to query the rows in which the value of the Col_Text column matches the whole phrase "hangzhou shanghai" in order in the data table:
/**
* Query the rows in which the value of the Col_Text column matches the whole phrase "hangzhou shanghai" in order in the data table. Tablestore returns the total number of rows that meet the query conditions and the specific data of some of these rows.
* @param client
*/
private static void matchPhraseQuery(SyncClient client) {
SearchQuery searchQuery = new SearchQuery();
MatchPhraseQuery matchPhraseQuery = new MatchPhraseQuery(); // Set the query type to MatchPhraseQuery.
matchPhraseQuery.setFieldName("Col_Text"); // Specify the name of the column to query.
matchPhraseQuery.setText("hangzhou shanghai"); // Specify the keyword that you want to match.
searchQuery.setQuery(matchPhraseQuery);
searchQuery.setOffset(0); // Set the offset parameter to 0.
searchQuery.setLimit(20); // Set limit to 20 to return up to 20 rows.
//searchQuery.setGetTotalCount(true); // Specify that the total number of matched rows is returned.
SearchRequest searchRequest = new SearchRequest("<TABLE_NAME>", "<SEARCH_INDEX_NAME>", searchQuery);
// You can configure the columnsToGet parameter to specify the columns 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.
//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 matched rows 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.