You can use a term query to query data that exactly matches the specified value of a field. Term queries are similar to queries based on string match conditions. If the type of the column is TEXT, Tablestore tokenizes the string and uses the tokens to match the keyword. A row meets the query conditions when at least one of the tokens in the row exactly matches the keyword. The keyword that is used to match the value of the column when you perform a term query is not tokenized.
Prerequisites
- A Tablestore client is initialized. For more information, see Initialize an OTSClient instance.
- 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 a search index.
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. To query only the number of rows that meet the query conditions without specific data, set the limit parameter to 0. |
queryType | The query type. Set this parameter to TableStore.QueryType.TERM_QUERY. |
fieldName | The name of the column that you want to query. |
term | The keyword that is used to match the value of the column when you perform a term query. This word is not tokenized. Instead, the entire word is used to match the column value. If the type of the column is TEXT, Tablestore tokenizes the string and uses the tokens to match the keyword. A row meets the query conditions when at least one of the tokens in the row exactly matches the keyword. For example, if the value of a column of the TEXT type in a row is "tablestore is cool", the value can be tokenized into "tablestore", "is", and "cool". The row meets the query conditions if you specify "tablestore", "is", or "cool" as the keyword to match the value of the column. |
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. |
columnToGet | Specifies whether to return all columns of each row that meets the query conditions. You can configure the returnType and returnNames fields for this parameter.
|
Example
The following sample code provides an example on how to query the rows in which the value of the Col_Keyword column exactly matches "hangzhou":
/**
* Search the table for rows in which the value of Col_Keyword exactly matches "hangzhou".
*/
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 specific data, set the limit parameter to 0.
query: { // Set the query type to TableStore.QueryType.TERM_QUERY.
queryType: TableStore.QueryType.TERM_QUERY,
query: {
fieldName: "Col_Keyword",
term: "hangzhou"
}
},
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 specifies 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 set the parameter to RETURN_SPECIFIED to return specific columns, RETURN_ALL to return all columns, RETURN_ALL_FROM_INDEX to return all columns in the search index, or RETURN_NONE 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));
});
FAQ
FAQ
References
The following query types are supported by search indexes: term query, terms query, match all query, match query, match phrase query, prefix query, range query, wildcard query, Boolean query, geo query, nested query, vector query, and exists query. You can select a query type to query data based on your business requirements.
If you want to sort or paginate the rows that meet the query conditions, you can use the sorting and paging feature. For more information, see Sorting and paging.
If you want to collapse the result set based on a specific column, you can use the collapse (distinct) feature. 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 data table, such as obtaining the extreme values, sum, and total number of rows, you can perform aggregation operations or execute SQL statements. For more information, see Aggregation and SQL query.
If you want to quickly 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.