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ResultSet¶
types~ResultSet(result, encoder, pagingStateopt)
Represents the result of a query.
Constructor¶
new ResultSet(result, encoder, pagingStateopt)
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
result |
rust.QueryResultWrapper | ||
encoder |
_Encoder | ||
pagingState |
rust.PagingStateResponseWrapper |
<optional> |
Members¶
(readonly) columns :Array:.<{String:, type:}>
Gets the columns returned in this ResultSet.
Type:
(readonly) info :Object
Information on the execution of a successful query:
Type:
- Object
Properties:
| Name | Type | Description |
|---|---|---|
achievedConsistency |
Number | The consistency level that has been actually achieved by the query. |
queriedHost |
String | The Cassandra host that coordinated this query. |
triedHosts |
Object | Gets the associative array of host that were queried before getting a valid response, being the last host the one that replied correctly. |
speculativeExecutions |
Object | The number of speculative executions (not including the first) executed before getting a valid response. |
traceId |
Uuid | Identifier of the trace session. |
warnings |
Array:.<string:> | Warning messages generated by the server when executing the query. |
isSchemaInAgreement |
Boolean | Whether the cluster had reached schema agreement after the execution of this query. TODO: Check if this is the case in rust driver: After a successful schema-altering query (ex: creating a table), the driver will check if
the cluster's nodes agree on the new schema version. If not, it will keep retrying for a given
delay (see Note that the schema agreement check is only performed for schema-altering queries For other
query types, this method will always return |
nextPage :function
Method used to manually fetch the next page of results. This method is only exposed when using the Client#eachRow method and there are more rows available in following pages.
Type:
- function
pageState :String|null
A string token representing the current page state of query. It can be used in the following executions to continue paging and retrieve the remained of the result for the query.
Type:
- String | null
- Default Value:
- null
(package) rawNextPageAsync
Internal method to get the next page asynchronously, without wrapping into a ResultSet.
rowLength :Number|undefined
Gets the row length of the result, regardless if the result has been buffered or not
Type:
- Number | undefined
rows :Array:.<Row:>|undefined
Gets an array rows returned by the query.
When the result set represents a response from a write query, this property will be undefined.
When the read query result contains more rows than the fetch size (5000), this property will only contain the
first rows up to fetch size. To obtain all the rows, you can use the built-in async iterator that will retrieve the
following pages of results.
Type:
Methods¶
@@asyncIterator() → {AsyncIterator:.<Row:>}
Gets the async iterator function.
Retrieves the async iterator representing the entire query result, the driver will fetch the following result pages.
Use the async iterator when the query result might contain more rows than the fetchSize.
Note that using the async iterator will not affect the internal state of the ResultSet instance.
You should avoid using both rows property that contains the row instances of the first page of
results, and the async iterator, that will yield all the rows in the result regardless on the number of pages.
Multiple concurrent async iterations are not supported.
Returns:
Example
Using for await...of statement
const query = 'SELECT user_id, post_id, content FROM timeline WHERE user_id = ?';
const result = await client.execute(query, [ id ], { prepare: true });
for await (const row of result) {
console.log(row['email']);
}@@iterator() → {Iterator:.<Row:>}
Gets the iterator function.
Retrieves the iterator of the underlying fetched rows, without causing the driver to fetch the following result pages. For more information on result paging, visit the documentation.
Returns:
Example
Using for...of statement
const query = 'SELECT user_id, post_id, content FROM timeline WHERE user_id = ?';
const result = await client.execute(query, [ id ], { prepare: true });
for (const row of result) {
console.log(row['email']);
}first()
Returns the first row or null if the result rows are empty.
isPaged() → {boolean}
Determines whether there are more pages of results.
If so, the driver will initially retrieve and contain only the first page of results.
To obtain all the rows, use the AsyncIterator.
Returns:
- Type
- boolean
wasApplied()
When this instance is the result of a conditional update query, it returns whether it was successful.
Otherwise, it returns true.
For consistency, this method always returns true for non-conditional queries (although there is
no reason to call the method in that case). This is also the case for conditional DDL statements
(CREATE KEYSPACE... IF NOT EXISTS, CREATE TABLE... IF NOT EXISTS), for which the server doesn't return
information whether it was applied or not.