When you perform a wildcard query, you can use the asterisk (*) and question mark (?) wildcard characters in the query to search for data. The asterisk (*) matches a string of any length at, before, or after a search term. The question mark (?) matches a single character in a specific position. The string can start with an asterisk (*) or a question mark (?). For example, if you search for the "table*e" string, "tablestore" can be matched.
The *word*
string is equivalent to the WHERE field_a LIKE '%word%'
clause in SQL. If you want to search for the *word* string, you can perform a fuzzy query that provides higher performance than a wildcard query. For more information about how to perform a fuzzy query, see Fuzzy query. If you perform a fuzzy query, the query performance is not compromised when the data volume increases.
Prerequisites
- A Tablestore client is initialized. For more information, see Initialization.
- A data table is created. Data is written to the table.
- A search index is created for the data table. For more information, see Create search indexes.
Parameters
Parameter | Description |
---|---|
tableName | The name of the data table. |
indexName | The name of the search index. |
offset | The position from which the current query starts. |
limit | The maximum number of rows that you want the current query to return. |
queryType | The query type. Set this parameter to TableStore.QueryType.WILDCARD_QUERY. |
fieldName | The name of the column. |
value | The string that contains wildcards. The string cannot exceed 32 characters in length. |
getTotalCount | Specifies whether to return the total number of rows that match the query conditions. By default, the value of this parameter is false, which indicates that the total number of rows that match the query conditions is not returned. If you set the getTotalCount parameter to true, the query performance is compromised. |
columnToGet | Specifies whether to return all columns of each row that meets the query conditions. You can configure returnType and returnNames for this parameter.
|
Examples
/**
* Search the table for rows in which the value of Col_Keyword matches "table*e".
*/
client.search({
tableName: TABLE_NAME,
indexName: INDEX_NAME,
searchQuery: {
offset: 0,
limit: 10, // To query only the number of rows that meet the query conditions without returning specific data, you can set limit to 0. This way, Tablestore returns the number of rows that meet the query conditions without specific data from the table.
query: { // Set the query type to TableStore.QueryType.WILDCARD_QUERY.
queryType: TableStore.QueryType.WILDCARD_QUERY,
query: {
fieldName: "Col_Keyword",
value: "table*e" // Specify a string that contains one or more wildcard characters in wildcardQuery.
}
},
getTotalCount: true // Specify whether to return the total number of rows that meet the query conditions. The default value of this parameter is false, which indicates that the total number of rows that meet the query conditions is not returned.
},
columnToGet: { // Specify the columns that you want to return. You can configure the RETURN_SPECIFIED parameter to return specified columns, the RETURN_ALL parameter to return all columns, the RETURN_ALL_FROM_INDEX parameter to return all columns in the search index, or the RETURN_NONE parameter to return only the primary key columns.
returnType: TableStore.ColumnReturnType.RETURN_ALL
}
}, function (err, data) {
if (err) {
console.log('error:', err);
return;
}
console.log('success:', JSON.stringify(data, null, 2));
});