@aws-sdk/client-dynamodb
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AWS SDK for JavaScript Dynamodb Client for Node.js, Browser and React Native
106 lines • 6.06 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.QueryCommand = void 0;
const models_0_1 = require("../models/models_0");
const Aws_json1_0_1 = require("../protocols/Aws_json1_0");
const middleware_serde_1 = require("@aws-sdk/middleware-serde");
const smithy_client_1 = require("@aws-sdk/smithy-client");
/**
* <p>The <code>Query</code> operation finds items based on primary key values.
* You can query any table or secondary index that has a composite primary key (a partition
* key and a sort key).
* </p>
* <p>Use the <code>KeyConditionExpression</code> parameter to provide a specific value
* for the partition key. The <code>Query</code> operation will return all of the items
* from the table or index with that partition key value. You can optionally narrow the
* scope of the <code>Query</code> operation by specifying a sort key value and a
* comparison operator in <code>KeyConditionExpression</code>. To further refine the <code>Query</code> results,
* you can optionally provide a <code>FilterExpression</code>. A <code>FilterExpression</code> determines which items
* within the results should be returned to you. All of the other results are discarded.
* </p>
* <p>
* A <code>Query</code> operation always returns a result set. If no matching items are found,
* the result set will be empty. Queries that do not return results consume the minimum number of
* read capacity units for that type of read operation.
* </p>
* <note>
* <p>
* DynamoDB calculates the number of read capacity units consumed based on item size,
* not on the amount of data that is returned to an application. The number of capacity
* units consumed will be the same whether you request all of the attributes (the default behavior)
* or just some of them (using a projection expression). The number will also be the same
* whether or not you use a <code>FilterExpression</code>.
* </p>
* </note>
* <p>
* <code>Query</code> results are always sorted by the sort key value. If the data type of the sort key is Number,
* the results are returned in numeric order; otherwise, the results are returned in order of UTF-8 bytes.
* By default, the sort order is ascending. To reverse the order, set the <code>ScanIndexForward</code> parameter
* to false.
* </p>
* <p> A single <code>Query</code> operation will read up to the maximum number of items
* set (if using the <code>Limit</code> parameter) or a maximum of 1 MB of data and then
* apply any filtering to the results using <code>FilterExpression</code>. If
* <code>LastEvaluatedKey</code> is present in the response, you will need to paginate
* the result set. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.Pagination">Paginating
* the Results</a> in the <i>Amazon DynamoDB Developer Guide</i>. </p>
* <p>
* <code>FilterExpression</code> is applied after a <code>Query</code> finishes, but before
* the results are returned.
* A <code>FilterExpression</code> cannot contain partition key or sort key attributes.
* You need to specify those attributes in the <code>KeyConditionExpression</code>.
* </p>
* <note>
* <p>
* A <code>Query</code> operation can return an empty result set and a <code>LastEvaluatedKey</code>
* if all the items read for the page of results are filtered out.
* </p>
* </note>
* <p>You can query a table, a local secondary index, or a global secondary index. For a
* query on a table or on a local secondary index, you can set the
* <code>ConsistentRead</code> parameter to <code>true</code> and obtain a
* strongly consistent result. Global secondary indexes support eventually consistent reads
* only, so do not specify <code>ConsistentRead</code> when querying a global
* secondary index.</p>
*/
class QueryCommand extends smithy_client_1.Command {
// Start section: command_properties
// End section: command_properties
constructor(input) {
// Start section: command_constructor
super();
this.input = input;
this.resolved = false;
// End section: command_constructor
}
/**
* @internal
*/
resolveMiddleware(clientStack, configuration, options) {
if (!this.resolved) {
this.middlewareStack.use(middleware_serde_1.getSerdePlugin(configuration, this.serialize, this.deserialize));
this.resolved = true;
}
const stack = clientStack.concat(this.middlewareStack);
const { logger } = configuration;
const clientName = "DynamoDBClient";
const commandName = "QueryCommand";
const handlerExecutionContext = {
logger,
clientName,
commandName,
inputFilterSensitiveLog: models_0_1.QueryInput.filterSensitiveLog,
outputFilterSensitiveLog: models_0_1.QueryOutput.filterSensitiveLog,
};
const { requestHandler } = configuration;
return stack.resolve((request) => requestHandler.handle(request.request, options || {}), handlerExecutionContext);
}
serialize(input, context) {
return Aws_json1_0_1.serializeAws_json1_0QueryCommand(input, context);
}
deserialize(output, context) {
return Aws_json1_0_1.deserializeAws_json1_0QueryCommand(output, context);
}
}
exports.QueryCommand = QueryCommand;
//# sourceMappingURL=QueryCommand.js.map