Class ScanRequest
- All Implemented Interfaces:
SdkPojo
,ToCopyableBuilder<ScanRequest.Builder,
ScanRequest>
Represents the input of a Scan
operation.
-
Nested Class Summary
-
Method Summary
Modifier and TypeMethodDescriptionThis is a legacy parameter.static ScanRequest.Builder
builder()
final ConditionalOperator
This is a legacy parameter.final String
This is a legacy parameter.final Boolean
A Boolean value that determines the read consistency model during the scan:final boolean
final boolean
equalsBySdkFields
(Object obj) Indicates whether some other object is "equal to" this one by SDK fields.final Map
<String, AttributeValue> The primary key of the first item that this operation will evaluate.One or more substitution tokens for attribute names in an expression.final Map
<String, AttributeValue> One or more values that can be substituted in an expression.final String
A string that contains conditions that DynamoDB applies after theScan
operation, but before the data is returned to you.final <T> Optional
<T> getValueForField
(String fieldName, Class<T> clazz) Used to retrieve the value of a field from any class that extendsSdkRequest
.final boolean
For responses, this returns true if the service returned a value for the AttributesToGet property.final boolean
For responses, this returns true if the service returned a value for the ExclusiveStartKey property.final boolean
For responses, this returns true if the service returned a value for the ExpressionAttributeNames property.final boolean
For responses, this returns true if the service returned a value for the ExpressionAttributeValues property.final int
hashCode()
final boolean
For responses, this returns true if the service returned a value for the ScanFilter property.final String
The name of a secondary index to scan.final Integer
limit()
The maximum number of items to evaluate (not necessarily the number of matching items).final String
A string that identifies one or more attributes to retrieve from the specified table or index.final ReturnConsumedCapacity
Returns the value of the ReturnConsumedCapacity property for this object.final String
Returns the value of the ReturnConsumedCapacity property for this object.This is a legacy parameter.final Integer
segment()
For a parallelScan
request,Segment
identifies an individual segment to be scanned by an application worker.final Select
select()
The attributes to be returned in the result.final String
The attributes to be returned in the result.static Class
<? extends ScanRequest.Builder> final String
The name of the table containing the requested items or if you provideIndexName
, the name of the table to which that index belongs.Take this object and create a builder that contains all of the current property values of this object.final String
toString()
Returns a string representation of this object.final Integer
For a parallelScan
request,TotalSegments
represents the total number of segments into which theScan
operation will be divided.Methods inherited from class software.amazon.awssdk.awscore.AwsRequest
overrideConfiguration
Methods inherited from interface software.amazon.awssdk.utils.builder.ToCopyableBuilder
copy
-
Method Details
-
tableName
The name of the table containing the requested items or if you provide
IndexName
, the name of the table to which that index belongs.You can also provide the Amazon Resource Name (ARN) of the table in this parameter.
- Returns:
- The name of the table containing the requested items or if you provide
IndexName
, the name of the table to which that index belongs.You can also provide the Amazon Resource Name (ARN) of the table in this parameter.
-
indexName
The name of a secondary index to scan. This index can be any local secondary index or global secondary index. Note that if you use the
IndexName
parameter, you must also provideTableName
.- Returns:
- The name of a secondary index to scan. This index can be any local secondary index or global secondary
index. Note that if you use the
IndexName
parameter, you must also provideTableName
.
-
hasAttributesToGet
public final boolean hasAttributesToGet()For responses, this returns true if the service returned a value for the AttributesToGet property. This DOES NOT check that the value is non-empty (for which, you should check theisEmpty()
method on the property). This is useful because the SDK will never return a null collection or map, but you may need to differentiate between the service returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true if a value for the property was specified in the request builder, and false if a value was not specified. -
attributesToGet
This is a legacy parameter. Use
ProjectionExpression
instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that you can differentiate between null and empty), you can use the
hasAttributesToGet()
method.- Returns:
- This is a legacy parameter. Use
ProjectionExpression
instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.
-
limit
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 inLastEvaluatedKey
to apply in a subsequent operation to continue the operation. For more information, see Working with Queries in the Amazon DynamoDB Developer Guide.- Returns:
- 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 inLastEvaluatedKey
to apply in a subsequent operation to continue the operation. For more information, see Working with Queries in the Amazon DynamoDB Developer Guide.
-
select
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 specifyingALL_ATTRIBUTES
. -
COUNT
- Returns the number of matching items, rather than the matching items themselves. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations. -
SPECIFIC_ATTRIBUTES
- Returns only the attributes listed inProjectionExpression
. This return value is equivalent to specifyingProjectionExpression
without specifying any value forSelect
.If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads 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
norProjectionExpression
are specified, DynamoDB defaults toALL_ATTRIBUTES
when accessing a table, andALL_PROJECTED_ATTRIBUTES
when accessing an index. You cannot use bothSelect
andProjectionExpression
together in a single request, unless the value forSelect
isSPECIFIC_ATTRIBUTES
. (This usage is equivalent to specifyingProjectionExpression
without any value forSelect
.)If you use the
ProjectionExpression
parameter, then the value forSelect
can only beSPECIFIC_ATTRIBUTES
. Any other value forSelect
will return an error.If the service returns an enum value that is not available in the current SDK version,
select
will returnSelect.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromselectAsString()
.- Returns:
- 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 specifyingALL_ATTRIBUTES
. -
COUNT
- Returns the number of matching items, rather than the matching items themselves. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations. -
SPECIFIC_ATTRIBUTES
- Returns only the attributes listed inProjectionExpression
. This return value is equivalent to specifyingProjectionExpression
without specifying any value forSelect
.If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads 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
norProjectionExpression
are specified, DynamoDB defaults toALL_ATTRIBUTES
when accessing a table, andALL_PROJECTED_ATTRIBUTES
when accessing an index. You cannot use bothSelect
andProjectionExpression
together in a single request, unless the value forSelect
isSPECIFIC_ATTRIBUTES
. (This usage is equivalent to specifyingProjectionExpression
without any value forSelect
.)If you use the
ProjectionExpression
parameter, then the value forSelect
can only beSPECIFIC_ATTRIBUTES
. Any other value forSelect
will return an error. -
- See Also:
-
-
selectAsString
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 specifyingALL_ATTRIBUTES
. -
COUNT
- Returns the number of matching items, rather than the matching items themselves. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations. -
SPECIFIC_ATTRIBUTES
- Returns only the attributes listed inProjectionExpression
. This return value is equivalent to specifyingProjectionExpression
without specifying any value forSelect
.If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads 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
norProjectionExpression
are specified, DynamoDB defaults toALL_ATTRIBUTES
when accessing a table, andALL_PROJECTED_ATTRIBUTES
when accessing an index. You cannot use bothSelect
andProjectionExpression
together in a single request, unless the value forSelect
isSPECIFIC_ATTRIBUTES
. (This usage is equivalent to specifyingProjectionExpression
without any value forSelect
.)If you use the
ProjectionExpression
parameter, then the value forSelect
can only beSPECIFIC_ATTRIBUTES
. Any other value forSelect
will return an error.If the service returns an enum value that is not available in the current SDK version,
select
will returnSelect.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromselectAsString()
.- Returns:
- 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 specifyingALL_ATTRIBUTES
. -
COUNT
- Returns the number of matching items, rather than the matching items themselves. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations. -
SPECIFIC_ATTRIBUTES
- Returns only the attributes listed inProjectionExpression
. This return value is equivalent to specifyingProjectionExpression
without specifying any value forSelect
.If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads 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
norProjectionExpression
are specified, DynamoDB defaults toALL_ATTRIBUTES
when accessing a table, andALL_PROJECTED_ATTRIBUTES
when accessing an index. You cannot use bothSelect
andProjectionExpression
together in a single request, unless the value forSelect
isSPECIFIC_ATTRIBUTES
. (This usage is equivalent to specifyingProjectionExpression
without any value forSelect
.)If you use the
ProjectionExpression
parameter, then the value forSelect
can only beSPECIFIC_ATTRIBUTES
. Any other value forSelect
will return an error. -
- See Also:
-
-
hasScanFilter
public final boolean hasScanFilter()For responses, this returns true if the service returned a value for the ScanFilter property. This DOES NOT check that the value is non-empty (for which, you should check theisEmpty()
method on the property). This is useful because the SDK will never return a null collection or map, but you may need to differentiate between the service returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true if a value for the property was specified in the request builder, and false if a value was not specified. -
scanFilter
This is a legacy parameter. Use
FilterExpression
instead. For more information, see ScanFilter in the Amazon DynamoDB Developer Guide.Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that you can differentiate between null and empty), you can use the
hasScanFilter()
method.- Returns:
- This is a legacy parameter. Use
FilterExpression
instead. For more information, see ScanFilter in the Amazon DynamoDB Developer Guide.
-
conditionalOperator
This is a legacy parameter. Use
FilterExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.If the service returns an enum value that is not available in the current SDK version,
conditionalOperator
will returnConditionalOperator.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromconditionalOperatorAsString()
.- Returns:
- This is a legacy parameter. Use
FilterExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide. - See Also:
-
conditionalOperatorAsString
This is a legacy parameter. Use
FilterExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.If the service returns an enum value that is not available in the current SDK version,
conditionalOperator
will returnConditionalOperator.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromconditionalOperatorAsString()
.- Returns:
- This is a legacy parameter. Use
FilterExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide. - See Also:
-
hasExclusiveStartKey
public final boolean hasExclusiveStartKey()For responses, this returns true if the service returned a value for the ExclusiveStartKey property. This DOES NOT check that the value is non-empty (for which, you should check theisEmpty()
method on the property). This is useful because the SDK will never return a null collection or map, but you may need to differentiate between the service returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true if a value for the property was specified in the request builder, and false if a value was not specified. -
exclusiveStartKey
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.In a parallel scan, a
Scan
request that includesExclusiveStartKey
must specify the same segment whose previousScan
returned the corresponding value ofLastEvaluatedKey
.Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that you can differentiate between null and empty), you can use the
hasExclusiveStartKey()
method.- Returns:
- 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.In a parallel scan, a
Scan
request that includesExclusiveStartKey
must specify the same segment whose previousScan
returned the corresponding value ofLastEvaluatedKey
.
-
returnConsumedCapacity
Returns the value of the ReturnConsumedCapacity property for this object.If the service returns an enum value that is not available in the current SDK version,
returnConsumedCapacity
will returnReturnConsumedCapacity.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromreturnConsumedCapacityAsString()
.- Returns:
- The value of the ReturnConsumedCapacity property for this object.
- See Also:
-
returnConsumedCapacityAsString
Returns the value of the ReturnConsumedCapacity property for this object.If the service returns an enum value that is not available in the current SDK version,
returnConsumedCapacity
will returnReturnConsumedCapacity.UNKNOWN_TO_SDK_VERSION
. The raw value returned by the service is available fromreturnConsumedCapacityAsString()
.- Returns:
- The value of the ReturnConsumedCapacity property for this object.
- See Also:
-
totalSegments
For a parallel
Scan
request,TotalSegments
represents the total number of segments into which theScan
operation will be divided. The value ofTotalSegments
corresponds to the number of application workers that will perform the parallel scan. For example, if you want to use four application threads to scan a table or an index, specify aTotalSegments
value of 4.The value for
TotalSegments
must be greater than or equal to 1, and less than or equal to 1000000. If you specify aTotalSegments
value of 1, theScan
operation will be sequential rather than parallel.If you specify
TotalSegments
, you must also specifySegment
.- Returns:
- For a parallel
Scan
request,TotalSegments
represents the total number of segments into which theScan
operation will be divided. The value ofTotalSegments
corresponds to the number of application workers that will perform the parallel scan. For example, if you want to use four application threads to scan a table or an index, specify aTotalSegments
value of 4.The value for
TotalSegments
must be greater than or equal to 1, and less than or equal to 1000000. If you specify aTotalSegments
value of 1, theScan
operation will be sequential rather than parallel.If you specify
TotalSegments
, you must also specifySegment
.
-
segment
For a parallel
Scan
request,Segment
identifies an individual segment to be scanned by an application worker.Segment IDs are zero-based, so the first segment is always 0. For example, if you want to use four application threads to scan a table or an index, then the first thread specifies a
Segment
value of 0, the second thread specifies 1, and so on.The value of
LastEvaluatedKey
returned from a parallelScan
request must be used asExclusiveStartKey
with the same segment ID in a subsequentScan
operation.The value for
Segment
must be greater than or equal to 0, and less than the value provided forTotalSegments
.If you provide
Segment
, you must also provideTotalSegments
.- Returns:
- For a parallel
Scan
request,Segment
identifies an individual segment to be scanned by an application worker.Segment IDs are zero-based, so the first segment is always 0. For example, if you want to use four application threads to scan a table or an index, then the first thread specifies a
Segment
value of 0, the second thread specifies 1, and so on.The value of
LastEvaluatedKey
returned from a parallelScan
request must be used asExclusiveStartKey
with the same segment ID in a subsequentScan
operation.The value for
Segment
must be greater than or equal to 0, and less than the value provided forTotalSegments
.If you provide
Segment
, you must also provideTotalSegments
.
-
projectionExpression
A string that identifies one or more attributes to retrieve from the specified table or index. 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 Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
- Returns:
- A string that identifies one or more attributes to retrieve from the specified table or index. 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 Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
-
filterExpression
A string that contains conditions that DynamoDB applies after the
Scan
operation, but before the data is returned to you. Items that do not satisfy theFilterExpression
criteria are not returned.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 in the Amazon DynamoDB Developer Guide.
- Returns:
- A string that contains conditions that DynamoDB applies after the
Scan
operation, but before the data is returned to you. Items that do not satisfy theFilterExpression
criteria are not returned.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 in the Amazon DynamoDB Developer Guide.
-
hasExpressionAttributeNames
public final boolean hasExpressionAttributeNames()For responses, this returns true if the service returned a value for the ExpressionAttributeNames property. This DOES NOT check that the value is non-empty (for which, you should check theisEmpty()
method on the property). This is useful because the SDK will never return a null collection or map, but you may need to differentiate between the service returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true if a value for the property was specified in the request builder, and false if a value was not specified. -
expressionAttributeNames
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 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 in the Amazon DynamoDB Developer Guide.
Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that you can differentiate between null and empty), you can use the
hasExpressionAttributeNames()
method.- Returns:
- 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 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 in the Amazon DynamoDB Developer Guide.
-
-
-
hasExpressionAttributeValues
public final boolean hasExpressionAttributeValues()For responses, this returns true if the service returned a value for the ExpressionAttributeValues property. This DOES NOT check that the value is non-empty (for which, you should check theisEmpty()
method on the property). This is useful because the SDK will never return a null collection or map, but you may need to differentiate between the service returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true if a value for the property was specified in the request builder, and false if a value was not specified. -
expressionAttributeValues
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 Condition Expressions in the Amazon DynamoDB Developer Guide.
Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that you can differentiate between null and empty), you can use the
hasExpressionAttributeValues()
method.- Returns:
- 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 Condition Expressions in the Amazon DynamoDB Developer Guide.
-
consistentRead
A Boolean value that determines the read consistency model during the scan:
-
If
ConsistentRead
isfalse
, then the data returned fromScan
might not contain the results from other recently completed write operations (PutItem
,UpdateItem
, orDeleteItem
). -
If
ConsistentRead
istrue
, then all of the write operations that completed before theScan
began are guaranteed to be contained in theScan
response.
The default setting for
ConsistentRead
isfalse
.The
ConsistentRead
parameter is not supported on global secondary indexes. If you scan a global secondary index withConsistentRead
set to true, you will receive aValidationException
.- Returns:
- A Boolean value that determines the read consistency model during the scan:
-
If
ConsistentRead
isfalse
, then the data returned fromScan
might not contain the results from other recently completed write operations (PutItem
,UpdateItem
, orDeleteItem
). -
If
ConsistentRead
istrue
, then all of the write operations that completed before theScan
began are guaranteed to be contained in theScan
response.
The default setting for
ConsistentRead
isfalse
.The
ConsistentRead
parameter is not supported on global secondary indexes. If you scan a global secondary index withConsistentRead
set to true, you will receive aValidationException
. -
-
-
toBuilder
Description copied from interface:ToCopyableBuilder
Take this object and create a builder that contains all of the current property values of this object.- Specified by:
toBuilder
in interfaceToCopyableBuilder<ScanRequest.Builder,
ScanRequest> - Specified by:
toBuilder
in classDynamoDbRequest
- Returns:
- a builder for type T
-
builder
-
serializableBuilderClass
-
hashCode
public final int hashCode()- Overrides:
hashCode
in classAwsRequest
-
equals
- Overrides:
equals
in classAwsRequest
-
equalsBySdkFields
Description copied from interface:SdkPojo
Indicates whether some other object is "equal to" this one by SDK fields. An SDK field is a modeled, non-inherited field in anSdkPojo
class, and is generated based on a service model.If an
SdkPojo
class does not have any inherited fields,equalsBySdkFields
andequals
are essentially the same.- Specified by:
equalsBySdkFields
in interfaceSdkPojo
- Parameters:
obj
- the object to be compared with- Returns:
- true if the other object equals to this object by sdk fields, false otherwise.
-
toString
Returns a string representation of this object. This is useful for testing and debugging. Sensitive data will be redacted from this string using a placeholder value. -
getValueForField
Description copied from class:SdkRequest
Used to retrieve the value of a field from any class that extendsSdkRequest
. The field name specified should match the member name from the corresponding service-2.json model specified in the codegen-resources folder for a given service. The class specifies what class to cast the returned value to. If the returned value is also a modeled class, theSdkRequest.getValueForField(String, Class)
method will again be available.- Overrides:
getValueForField
in classSdkRequest
- Parameters:
fieldName
- The name of the member to be retrieved.clazz
- The class to cast the returned object to.- Returns:
- Optional containing the casted return value
-
sdkFields
-