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api_op_Query.go
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api_op_Query.go
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// Code generated by smithy-go-codegen DO NOT EDIT.
package dynamodb
import (
"context"
"fmt"
awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
"github.com/aws/aws-sdk-go-v2/aws/signer/v4"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
internalEndpointDiscovery "github.com/aws/aws-sdk-go-v2/service/internal/endpoint-discovery"
"github.com/aws/smithy-go/middleware"
smithyhttp "github.com/aws/smithy-go/transport/http"
)
// You must provide the name of the partition key attribute and a single value for
// that attribute. Query returns all items with that partition key value.
// Optionally, you can provide a sort key attribute and use a comparison operator
// to refine the search results. Use the KeyConditionExpression parameter to
// provide a specific value for the partition key. The Query 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 Query operation by specifying a sort key
// value and a comparison operator in KeyConditionExpression. To further refine the
// Query results, you can optionally provide a FilterExpression. A FilterExpression
// determines which items within the results should be returned to you. All of the
// other results are discarded. A Query 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. 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 FilterExpression. Query 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 ScanIndexForward
// parameter to false. A single Query operation will read up to the maximum number
// of items set (if using the Limit parameter) or a maximum of 1 MB of data and
// then apply any filtering to the results using FilterExpression. If
// LastEvaluatedKey is present in the response, you will need to paginate the
// result set. For more information, see Paginating the Results
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.Pagination)
// in the Amazon DynamoDB Developer Guide. FilterExpression is applied after a
// Query finishes, but before the results are returned. A FilterExpression cannot
// contain partition key or sort key attributes. You need to specify those
// attributes in the KeyConditionExpression. A Query operation can return an empty
// result set and a LastEvaluatedKey if all the items read for the page of results
// are filtered out. 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 ConsistentRead parameter to true and obtain a strongly consistent
// result. Global secondary indexes support eventually consistent reads only, so do
// not specify ConsistentRead when querying a global secondary index.
func (c *Client) Query(ctx context.Context, params *QueryInput, optFns ...func(*Options)) (*QueryOutput, error) {
if params == nil {
params = &QueryInput{}
}
result, metadata, err := c.invokeOperation(ctx, "Query", params, optFns, c.addOperationQueryMiddlewares)
if err != nil {
return nil, err
}
out := result.(*QueryOutput)
out.ResultMetadata = metadata
return out, nil
}
// Represents the input of a Query operation.
type QueryInput struct {
// The name of the table containing the requested items.
//
// This member is required.
TableName *string
// This is a legacy parameter. Use ProjectionExpression instead. For more
// information, see AttributesToGet
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html)
// in the Amazon DynamoDB Developer Guide.
AttributesToGet []string
// This is a legacy parameter. Use FilterExpression instead. For more information,
// see ConditionalOperator
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html)
// in the Amazon DynamoDB Developer Guide.
ConditionalOperator types.ConditionalOperator
// Determines the read consistency model: If set to true, then the operation uses
// strongly consistent reads; otherwise, the operation uses eventually consistent
// reads. Strongly consistent reads are not supported on global secondary indexes.
// If you query a global secondary index with ConsistentRead set to true, you will
// receive a ValidationException.
ConsistentRead *bool
// The primary key of the first item that this operation will evaluate. Use the
// value that was returned for LastEvaluatedKey in the previous operation. The data
// type for ExclusiveStartKey must be String, Number, or Binary. No set data types
// are allowed.
ExclusiveStartKey map[string]types.AttributeValue
// One or more substitution tokens for attribute names in an expression. The
// following are some use cases for using ExpressionAttributeNames:
//
// * To access an
// attribute whose name conflicts with a DynamoDB reserved word.
//
// * To create a
// placeholder for repeating occurrences of an attribute name in an expression.
//
// *
// To prevent special characters in an attribute name from being misinterpreted in
// an expression.
//
// Use the # character in an expression to dereference an attribute
// name. For example, consider the following attribute name:
//
// * Percentile
//
// The
// name of this attribute conflicts with a reserved word, so it cannot be used
// directly in an expression. (For the complete list of reserved words, see
// Reserved Words
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html)
// in the Amazon DynamoDB Developer Guide). To work around this, you could specify
// the following for ExpressionAttributeNames:
//
// * {"#P":"Percentile"}
//
// You could
// then use this substitution in an expression, as in this example:
//
// * #P =
// :val
//
// Tokens that begin with the : character are expression attribute values,
// which are placeholders for the actual value at runtime. For more information on
// expression attribute names, see Specifying Item Attributes
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html)
// in the Amazon DynamoDB Developer Guide.
ExpressionAttributeNames map[string]string
// One or more values that can be substituted in an expression. Use the : (colon)
// character in an expression to dereference an attribute value. For example,
// suppose that you wanted to check whether the value of the ProductStatus
// attribute was one of the following: Available | Backordered | Discontinued You
// would first need to specify ExpressionAttributeValues as follows: {
// ":avail":{"S":"Available"}, ":back":{"S":"Backordered"},
// ":disc":{"S":"Discontinued"} } You could then use these values in an expression,
// such as this: ProductStatus IN (:avail, :back, :disc) For more information on
// expression attribute values, see Specifying Conditions
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html)
// in the Amazon DynamoDB Developer Guide.
ExpressionAttributeValues map[string]types.AttributeValue
// A string that contains conditions that DynamoDB applies after the Query
// operation, but before the data is returned to you. Items that do not satisfy the
// FilterExpression criteria are not returned. A FilterExpression does not allow
// key attributes. You cannot define a filter expression based on a partition key
// or a sort key. A FilterExpression is applied after the items have already been
// read; the process of filtering does not consume any additional read capacity
// units. For more information, see Filter Expressions
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#Query.FilterExpression)
// in the Amazon DynamoDB Developer Guide.
FilterExpression *string
// The name of an index to query. This index can be any local secondary index or
// global secondary index on the table. Note that if you use the IndexName
// parameter, you must also provide TableName.
IndexName *string
// The condition that specifies the key values for items to be retrieved by the
// Query action. The condition must perform an equality test on a single partition
// key value. The condition can optionally perform one of several comparison tests
// on a single sort key value. This allows Query to retrieve one item with a given
// partition key value and sort key value, or several items that have the same
// partition key value but different sort key values. The partition key equality
// test is required, and must be specified in the following format:
// partitionKeyName = :partitionkeyval If you also want to provide a condition for
// the sort key, it must be combined using AND with the condition for the sort key.
// Following is an example, using the = comparison operator for the sort key:
// partitionKeyName
// =
//
// :partitionkeyval
//
// AND
//
// sortKeyName
//
//
// =
//
// :sortkeyval Valid comparisons for the sort key condition are as follows:
//
// *
// sortKeyName=:sortkeyval - true if the sort key value is equal to :sortkeyval.
//
// *
// sortKeyName<:sortkeyval - true if the sort key value is less than
// :sortkeyval.
//
// * sortKeyName<=:sortkeyval - true if the sort key value is less
// than or equal to :sortkeyval.
//
// * sortKeyName>:sortkeyval - true if the sort key
// value is greater than :sortkeyval.
//
// * sortKeyName>= :sortkeyval - true if the
// sort key value is greater than or equal to :sortkeyval.
//
// *
// sortKeyNameBETWEEN:sortkeyval1AND:sortkeyval2 - true if the sort key value is
// greater than or equal to :sortkeyval1, and less than or equal to
// :sortkeyval2.
//
// * begins_with (sortKeyName, :sortkeyval) - true if the sort key
// value begins with a particular operand. (You cannot use this function with a
// sort key that is of type Number.) Note that the function name begins_with is
// case-sensitive.
//
// Use the ExpressionAttributeValues parameter to replace tokens
// such as :partitionval and :sortval with actual values at runtime. You can
// optionally use the ExpressionAttributeNames parameter to replace the names of
// the partition key and sort key with placeholder tokens. This option might be
// necessary if an attribute name conflicts with a DynamoDB reserved word. For
// example, the following KeyConditionExpression parameter causes an error because
// Size is a reserved word:
//
// * Size = :myval
//
// To work around this, define a
// placeholder (such a #S) to represent the attribute name Size.
// KeyConditionExpression then is as follows:
//
// * #S = :myval
//
// For a list of
// reserved words, see Reserved Words
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html)
// in the Amazon DynamoDB Developer Guide. For more information on
// ExpressionAttributeNames and ExpressionAttributeValues, see Using Placeholders
// for Attribute Names and Values
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ExpressionPlaceholders.html)
// in the Amazon DynamoDB Developer Guide.
KeyConditionExpression *string
// This is a legacy parameter. Use KeyConditionExpression instead. For more
// information, see KeyConditions
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.KeyConditions.html)
// in the Amazon DynamoDB Developer Guide.
KeyConditions map[string]types.Condition
// The maximum number of items to evaluate (not necessarily the number of matching
// items). If DynamoDB processes the number of items up to the limit while
// processing the results, it stops the operation and returns the matching values
// up to that point, and a key in LastEvaluatedKey to apply in a subsequent
// operation, so that you can pick up where you left off. Also, if the processed
// dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the
// operation and returns the matching values up to the limit, and a key in
// LastEvaluatedKey to apply in a subsequent operation to continue the operation.
// For more information, see Query and Scan
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html)
// in the Amazon DynamoDB Developer Guide.
Limit *int32
// A string that identifies one or more attributes to retrieve from the table.
// These attributes can include scalars, sets, or elements of a JSON document. The
// attributes in the expression must be separated by commas. If no attribute names
// are specified, then all attributes will be returned. If any of the requested
// attributes are not found, they will not appear in the result. For more
// information, see Accessing Item Attributes
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html)
// in the Amazon DynamoDB Developer Guide.
ProjectionExpression *string
// This is a legacy parameter. Use FilterExpression instead. For more information,
// see QueryFilter
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.QueryFilter.html)
// in the Amazon DynamoDB Developer Guide.
QueryFilter map[string]types.Condition
// Determines the level of detail about either provisioned or on-demand throughput
// consumption that is returned in the response:
//
// * INDEXES - The response includes
// the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity
// for each table and secondary index that was accessed. Note that some operations,
// such as GetItem and BatchGetItem, do not access any indexes at all. In these
// cases, specifying INDEXES will only return ConsumedCapacity information for
// table(s).
//
// * TOTAL - The response includes only the aggregate ConsumedCapacity
// for the operation.
//
// * NONE - No ConsumedCapacity details are included in the
// response.
ReturnConsumedCapacity types.ReturnConsumedCapacity
// Specifies the order for index traversal: If true (default), the traversal is
// performed in ascending order; if false, the traversal is performed in descending
// order. Items with the same partition key value are stored in sorted order by
// sort key. If the sort key data type is Number, the results are stored in numeric
// order. For type String, the results are stored in order of UTF-8 bytes. For type
// Binary, DynamoDB treats each byte of the binary data as unsigned. If
// ScanIndexForward is true, DynamoDB returns the results in the order in which
// they are stored (by sort key value). This is the default behavior. If
// ScanIndexForward is false, DynamoDB reads the results in reverse order by sort
// key value, and then returns the results to the client.
ScanIndexForward *bool
// The attributes to be returned in the result. You can retrieve all item
// attributes, specific item attributes, the count of matching items, or in the
// case of an index, some or all of the attributes projected into the index.
//
// *
// ALL_ATTRIBUTES - Returns all of the item attributes from the specified table or
// index. If you query a local secondary index, then for each matching item in the
// index, DynamoDB fetches the entire item from the parent table. If the index is
// configured to project all item attributes, then all of the data can be obtained
// from the local secondary index, and no fetching is required.
//
// *
// ALL_PROJECTED_ATTRIBUTES - Allowed only when querying an index. Retrieves all
// attributes that have been projected into the index. If the index is configured
// to project all attributes, this return value is equivalent to specifying
// ALL_ATTRIBUTES.
//
// * COUNT - Returns the number of matching items, rather than the
// matching items themselves.
//
// * SPECIFIC_ATTRIBUTES - Returns only the attributes
// listed in ProjectionExpression. This return value is equivalent to specifying
// ProjectionExpression without specifying any value for Select. If you query or
// scan a local secondary index and request only attributes that are projected into
// that index, the operation will read only the index and not the table. If any of
// the requested attributes are not projected into the local secondary index,
// DynamoDB fetches each of these attributes from the parent table. This extra
// fetching incurs additional throughput cost and latency. If you query or scan a
// global secondary index, you can only request attributes that are projected into
// the index. Global secondary index queries cannot fetch attributes from the
// parent table.
//
// If neither Select nor ProjectionExpression are specified,
// DynamoDB defaults to ALL_ATTRIBUTES when accessing a table, and
// ALL_PROJECTED_ATTRIBUTES when accessing an index. You cannot use both Select and
// ProjectionExpression together in a single request, unless the value for Select
// is SPECIFIC_ATTRIBUTES. (This usage is equivalent to specifying
// ProjectionExpression without any value for Select.) If you use the
// ProjectionExpression parameter, then the value for Select can only be
// SPECIFIC_ATTRIBUTES. Any other value for Select will return an error.
Select types.Select
noSmithyDocumentSerde
}
// Represents the output of a Query operation.
type QueryOutput struct {
// The capacity units consumed by the Query operation. The data returned includes
// the total provisioned throughput consumed, along with statistics for the table
// and any indexes involved in the operation. ConsumedCapacity is only returned if
// the ReturnConsumedCapacity parameter was specified. For more information, see
// Provisioned Throughput
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ProvisionedThroughputIntro.html)
// in the Amazon DynamoDB Developer Guide.
ConsumedCapacity *types.ConsumedCapacity
// The number of items in the response. If you used a QueryFilter in the request,
// then Count is the number of items returned after the filter was applied, and
// ScannedCount is the number of matching items before the filter was applied. If
// you did not use a filter in the request, then Count and ScannedCount are the
// same.
Count int32
// An array of item attributes that match the query criteria. Each element in this
// array consists of an attribute name and the value for that attribute.
Items []map[string]types.AttributeValue
// The primary key of the item where the operation stopped, inclusive of the
// previous result set. Use this value to start a new operation, excluding this
// value in the new request. If LastEvaluatedKey is empty, then the "last page" of
// results has been processed and there is no more data to be retrieved. If
// LastEvaluatedKey is not empty, it does not necessarily mean that there is more
// data in the result set. The only way to know when you have reached the end of
// the result set is when LastEvaluatedKey is empty.
LastEvaluatedKey map[string]types.AttributeValue
// The number of items evaluated, before any QueryFilter is applied. A high
// ScannedCount value with few, or no, Count results indicates an inefficient Query
// operation. For more information, see Count and ScannedCount
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#Count)
// in the Amazon DynamoDB Developer Guide. If you did not use a filter in the
// request, then ScannedCount is the same as Count.
ScannedCount int32
// Metadata pertaining to the operation's result.
ResultMetadata middleware.Metadata
noSmithyDocumentSerde
}
func (c *Client) addOperationQueryMiddlewares(stack *middleware.Stack, options Options) (err error) {
err = stack.Serialize.Add(&awsAwsjson10_serializeOpQuery{}, middleware.After)
if err != nil {
return err
}
err = stack.Deserialize.Add(&awsAwsjson10_deserializeOpQuery{}, middleware.After)
if err != nil {
return err
}
if err = addSetLoggerMiddleware(stack, options); err != nil {
return err
}
if err = awsmiddleware.AddClientRequestIDMiddleware(stack); err != nil {
return err
}
if err = smithyhttp.AddComputeContentLengthMiddleware(stack); err != nil {
return err
}
if err = addResolveEndpointMiddleware(stack, options); err != nil {
return err
}
if err = v4.AddComputePayloadSHA256Middleware(stack); err != nil {
return err
}
if err = addRetryMiddlewares(stack, options); err != nil {
return err
}
if err = addHTTPSignerV4Middleware(stack, options); err != nil {
return err
}
if err = awsmiddleware.AddRawResponseToMetadata(stack); err != nil {
return err
}
if err = awsmiddleware.AddRecordResponseTiming(stack); err != nil {
return err
}
if err = addClientUserAgent(stack); err != nil {
return err
}
if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
return err
}
if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
return err
}
if err = addOpQueryDiscoverEndpointMiddleware(stack, options, c); err != nil {
return err
}
if err = addOpQueryValidationMiddleware(stack); err != nil {
return err
}
if err = stack.Initialize.Add(newServiceMetadataMiddleware_opQuery(options.Region), middleware.Before); err != nil {
return err
}
if err = addRequestIDRetrieverMiddleware(stack); err != nil {
return err
}
if err = addResponseErrorMiddleware(stack); err != nil {
return err
}
if err = addValidateResponseChecksum(stack, options); err != nil {
return err
}
if err = addAcceptEncodingGzip(stack, options); err != nil {
return err
}
if err = addRequestResponseLogging(stack, options); err != nil {
return err
}
return nil
}
func addOpQueryDiscoverEndpointMiddleware(stack *middleware.Stack, o Options, c *Client) error {
return stack.Serialize.Insert(&internalEndpointDiscovery.DiscoverEndpoint{
Options: []func(*internalEndpointDiscovery.DiscoverEndpointOptions){
func(opt *internalEndpointDiscovery.DiscoverEndpointOptions) {
opt.DisableHTTPS = o.EndpointOptions.DisableHTTPS
opt.Logger = o.Logger
},
},
DiscoverOperation: c.fetchOpQueryDiscoverEndpoint,
EndpointDiscoveryEnableState: o.EndpointDiscovery.EnableEndpointDiscovery,
EndpointDiscoveryRequired: false,
}, "ResolveEndpoint", middleware.After)
}
func (c *Client) fetchOpQueryDiscoverEndpoint(ctx context.Context, input interface{}, optFns ...func(*internalEndpointDiscovery.DiscoverEndpointOptions)) (internalEndpointDiscovery.WeightedAddress, error) {
in, ok := input.(*QueryInput)
if !ok {
return internalEndpointDiscovery.WeightedAddress{}, fmt.Errorf("unknown input type %T", input)
}
_ = in
identifierMap := make(map[string]string, 0)
key := fmt.Sprintf("DynamoDB.%v", identifierMap)
if v, ok := c.endpointCache.Get(key); ok {
return v, nil
}
discoveryOperationInput := &DescribeEndpointsInput{}
opt := internalEndpointDiscovery.DiscoverEndpointOptions{}
for _, fn := range optFns {
fn(&opt)
}
go c.handleEndpointDiscoveryFromService(ctx, discoveryOperationInput, key, opt)
return internalEndpointDiscovery.WeightedAddress{}, nil
}
// QueryAPIClient is a client that implements the Query operation.
type QueryAPIClient interface {
Query(context.Context, *QueryInput, ...func(*Options)) (*QueryOutput, error)
}
var _ QueryAPIClient = (*Client)(nil)
// QueryPaginatorOptions is the paginator options for Query
type QueryPaginatorOptions struct {
// The maximum number of items to evaluate (not necessarily the number of matching
// items). If DynamoDB processes the number of items up to the limit while
// processing the results, it stops the operation and returns the matching values
// up to that point, and a key in LastEvaluatedKey to apply in a subsequent
// operation, so that you can pick up where you left off. Also, if the processed
// dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the
// operation and returns the matching values up to the limit, and a key in
// LastEvaluatedKey to apply in a subsequent operation to continue the operation.
// For more information, see Query and Scan
// (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html)
// in the Amazon DynamoDB Developer Guide.
Limit int32
}
// QueryPaginator is a paginator for Query
type QueryPaginator struct {
options QueryPaginatorOptions
client QueryAPIClient
params *QueryInput
nextToken map[string]types.AttributeValue
firstPage bool
}
// NewQueryPaginator returns a new QueryPaginator
func NewQueryPaginator(client QueryAPIClient, params *QueryInput, optFns ...func(*QueryPaginatorOptions)) *QueryPaginator {
if params == nil {
params = &QueryInput{}
}
options := QueryPaginatorOptions{}
if params.Limit != nil {
options.Limit = *params.Limit
}
for _, fn := range optFns {
fn(&options)
}
return &QueryPaginator{
options: options,
client: client,
params: params,
firstPage: true,
nextToken: params.ExclusiveStartKey,
}
}
// HasMorePages returns a boolean indicating whether more pages are available
func (p *QueryPaginator) HasMorePages() bool {
return p.firstPage || p.nextToken != nil
}
// NextPage retrieves the next Query page.
func (p *QueryPaginator) NextPage(ctx context.Context, optFns ...func(*Options)) (*QueryOutput, error) {
if !p.HasMorePages() {
return nil, fmt.Errorf("no more pages available")
}
params := *p.params
params.ExclusiveStartKey = p.nextToken
var limit *int32
if p.options.Limit > 0 {
limit = &p.options.Limit
}
params.Limit = limit
result, err := p.client.Query(ctx, ¶ms, optFns...)
if err != nil {
return nil, err
}
p.firstPage = false
prevToken := p.nextToken
p.nextToken = result.LastEvaluatedKey
_ = prevToken
return result, nil
}
func newServiceMetadataMiddleware_opQuery(region string) *awsmiddleware.RegisterServiceMetadata {
return &awsmiddleware.RegisterServiceMetadata{
Region: region,
ServiceID: ServiceID,
SigningName: "dynamodb",
OperationName: "Query",
}
}