Tablestore:Wildcard query

Query request

request is of the tablestore.SearchRequest type and contains the following parameters.

Query configuration

Create a query configuration by calling search.NewSearchQuery() and configure it by using the following methods.

Query condition

The query is of the search.WildcardQuery type and contains the following parameters.

Columns to return

request.ColumnsToGet is of the tablestore.ColumnsToGet type and contains the following parameters.

Improve substring query performance

For a query pattern such as *word*, configure the Text field with the fuzzy analyzer when you create the search index, and use a match phrase query to query the field. This approach typically performs better than a wildcard query for matching a substring. For matching rules and limits, see Token-based wildcard queries.

The following example creates a search index that contains the file_name field and configures the fuzzy analyzer for the field.

analyzer := tablestore.Analyzer_Fuzzy
fieldSchema := &tablestore.FieldSchema{
    FieldName:         proto.String("file_name"),
    FieldType:         tablestore.FieldType_TEXT,
    Index:             proto.Bool(true),
    Analyzer:          &analyzer,
    AnalyzerParameter: tablestore.FuzzyAnalyzerParameter{},
}

request := &tablestore.CreateSearchIndexRequest{
    TableName: "example_table",
    IndexName: "example_index",
    IndexSchema: &tablestore.IndexSchema{
        FieldSchemas: []*tablestore.FieldSchema{fieldSchema},
    },
}

_, err := client.CreateSearchIndex(request)
if err != nil {
    log.Fatal(err)
}

After the index data is synchronized, use a MatchPhraseQuery to query rows in which the file_name field contains word at any position.

query := &search.MatchPhraseQuery{
    FieldName: "file_name",
    Text:      "word",
}
searchQuery := search.NewSearchQuery().
    SetQuery(query).
    SetLimit(10)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   "example_table",
    IndexName:   "example_index",
    SearchQuery: searchQuery,
    ColumnsToGet: &tablestore.ColumnsToGet{
        ReturnAllFromIndex: true,
    },
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.Rows)

Exclude rows that match a wildcard pattern

To implement the equivalent of SQL NOT LIKE, add a WildcardQuery to BoolQuery.MustNotQueries.

wildcardQuery := &search.WildcardQuery{
    FieldName: "category",
    Value:     "book-*",
}
query := &search.BoolQuery{
    MustNotQueries: []search.Query{wildcardQuery},
}
searchQuery := search.NewSearchQuery().
    SetQuery(query).
    SetLimit(10)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   "example_table",
    IndexName:   "example_index",
    SearchQuery: searchQuery,
    ColumnsToGet: &tablestore.ColumnsToGet{
        ReturnAllFromIndex: true,
    },
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.Rows)