Copyright | (c) 2013-2018 Brendan Hay |
---|---|
License | Mozilla Public License, v. 2.0. |
Maintainer | Brendan Hay <brendan.g.hay+amazonka@gmail.com> |
Stability | auto-generated |
Portability | non-portable (GHC extensions) |
Safe Haskell | None |
Language | Haskell2010 |
Edits an existing item's attributes, or adds a new item to the table if it does not already exist. You can put, delete, or add attribute values. You can also perform a conditional update on an existing item (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).
You can also return the item's attribute values in the same UpdateItem
operation using the ReturnValues
parameter.
Synopsis
- updateItem :: Text -> UpdateItem
- data UpdateItem
- uiExpressionAttributeNames :: Lens' UpdateItem (HashMap Text Text)
- uiReturnValues :: Lens' UpdateItem (Maybe ReturnValue)
- uiUpdateExpression :: Lens' UpdateItem (Maybe Text)
- uiExpressionAttributeValues :: Lens' UpdateItem (HashMap Text AttributeValue)
- uiAttributeUpdates :: Lens' UpdateItem (HashMap Text AttributeValueUpdate)
- uiReturnConsumedCapacity :: Lens' UpdateItem (Maybe ReturnConsumedCapacity)
- uiReturnItemCollectionMetrics :: Lens' UpdateItem (Maybe ReturnItemCollectionMetrics)
- uiConditionExpression :: Lens' UpdateItem (Maybe Text)
- uiConditionalOperator :: Lens' UpdateItem (Maybe ConditionalOperator)
- uiExpected :: Lens' UpdateItem (HashMap Text ExpectedAttributeValue)
- uiTableName :: Lens' UpdateItem Text
- uiKey :: Lens' UpdateItem (HashMap Text AttributeValue)
- updateItemResponse :: Int -> UpdateItemResponse
- data UpdateItemResponse
- uirsItemCollectionMetrics :: Lens' UpdateItemResponse (Maybe ItemCollectionMetrics)
- uirsConsumedCapacity :: Lens' UpdateItemResponse (Maybe ConsumedCapacity)
- uirsAttributes :: Lens' UpdateItemResponse (HashMap Text AttributeValue)
- uirsResponseStatus :: Lens' UpdateItemResponse Int
Creating a Request
Creates a value of UpdateItem
with the minimum fields required to make a request.
Use one of the following lenses to modify other fields as desired:
uiExpressionAttributeNames
- One or more substitution tokens for attribute names in an expression. The following are some use cases for usingExpressionAttributeNames
: * 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 forExpressionAttributeNames
: *{"#P":Percentile}
You could then use this substitution in an expression, as in this example: *#P = :val
For more information on expression attribute names, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide .uiReturnValues
- UseReturnValues
if you want to get the item attributes as they appear before or after they are updated. ForUpdateItem
, the valid values are: *NONE
- IfReturnValues
is not specified, or if its value isNONE
, then nothing is returned. (This setting is the default forReturnValues
.) *ALL_OLD
- Returns all of the attributes of the item, as they appeared before the UpdateItem operation. *UPDATED_OLD
- Returns only the updated attributes, as they appeared before the UpdateItem operation. *ALL_NEW
- Returns all of the attributes of the item, as they appear after the UpdateItem operation. *UPDATED_NEW
- Returns only the updated attributes, as they appear after the UpdateItem operation. There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed. The values returned are strongly consistent.uiUpdateExpression
- An expression that defines one or more attributes to be updated, the action to be performed on them, and new value(s) for them. The following action values are available forUpdateExpression
. *SET
- Adds one or more attributes and values to an item. If any of these attribute already exist, they are replaced by the new values. You can also useSET
to add or subtract from an attribute that is of type Number. For example:SET myNum = myNum + :val
SET
supports the following functions: *if_not_exists (path, operand)
- if the item does not contain an attribute at the specified path, thenif_not_exists
evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item. *list_append (operand, operand)
- evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands. These function names are case-sensitive. *REMOVE
- Removes one or more attributes from an item. *ADD
- Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior ofADD
depends on the data type of the attribute: * If the existing attribute is a number, and ifValue
is also a number, thenValue
is mathematically added to the existing attribute. IfValue
is a negative number, then it is subtracted from the existing attribute. * If the existing data type is a set and ifValue
is also a set, thenValue
is added to the existing set. For example, if the attribute value is the set[1,2]
, and theADD
action specified[3]
, then the final attribute value is[1,2,3]
. An error occurs if anADD
action is specified for a set attribute and the attribute type specified does not match the existing set type. Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, theValue
must also be a set of strings. Important: TheADD
action only supports Number and set data types. In addition,ADD
can only be used on top-level attributes, not nested attributes. *DELETE
- Deletes an element from a set. If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set[a,b,c]
and theDELETE
action specifies[a,c]
, then the final attribute value is[b]
. Specifying an empty set is an error. Important: TheDELETE
action only supports set data types. In addition,DELETE
can only be used on top-level attributes, not nested attributes. You can have many actions in a single expression, such as the following:SET a=:value1, b=:value2 DELETE :value3, :value4, :value5
For more information on update expressions, see Modifying Items and Attributes in the Amazon DynamoDB Developer Guide .uiExpressionAttributeValues
- 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 specifyExpressionAttributeValues
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 in the Amazon DynamoDB Developer Guide .uiAttributeUpdates
- This is a legacy parameter. UseUpdateExpression
instead. For more information, see AttributeUpdates in the Amazon DynamoDB Developer Guide .uiReturnConsumedCapacity
- Undocumented member.uiReturnItemCollectionMetrics
- Determines whether item collection metrics are returned. If set toSIZE
, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set toNONE
(the default), no statistics are returned.uiConditionExpression
- A condition that must be satisfied in order for a conditional update to succeed. An expression can contain any of the following: * Functions:attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size
These function names are case-sensitive. * Comparison operators:= | <> | | | |= | BETWEEN | IN
* Logical operators:AND | OR | NOT
For more information on condition expressions, see Specifying Conditions in the Amazon DynamoDB Developer Guide .uiConditionalOperator
- This is a legacy parameter. UseConditionExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide .uiExpected
- This is a legacy parameter. UseConditionExpression
instead. For more information, see Expected in the Amazon DynamoDB Developer Guide .uiTableName
- The name of the table containing the item to update.uiKey
- The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute. For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
data UpdateItem Source #
Represents the input of an UpdateItem
operation.
See: updateItem
smart constructor.
Instances
Request Lenses
uiExpressionAttributeNames :: Lens' UpdateItem (HashMap Text Text) Source #
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
For more information on expression attribute names, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide .
uiReturnValues :: Lens' UpdateItem (Maybe ReturnValue) Source #
Use ReturnValues
if you want to get the item attributes as they appear before or after they are updated. For UpdateItem
, the valid values are: * NONE
- If ReturnValues
is not specified, or if its value is NONE
, then nothing is returned. (This setting is the default for ReturnValues
.) * ALL_OLD
- Returns all of the attributes of the item, as they appeared before the UpdateItem operation. * UPDATED_OLD
- Returns only the updated attributes, as they appeared before the UpdateItem operation. * ALL_NEW
- Returns all of the attributes of the item, as they appear after the UpdateItem operation. * UPDATED_NEW
- Returns only the updated attributes, as they appear after the UpdateItem operation. There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed. The values returned are strongly consistent.
uiUpdateExpression :: Lens' UpdateItem (Maybe Text) Source #
An expression that defines one or more attributes to be updated, the action to be performed on them, and new value(s) for them. The following action values are available for UpdateExpression
. * SET
- Adds one or more attributes and values to an item. If any of these attribute already exist, they are replaced by the new values. You can also use SET
to add or subtract from an attribute that is of type Number. For example: SET myNum = myNum + :val
SET
supports the following functions: * if_not_exists (path, operand)
- if the item does not contain an attribute at the specified path, then if_not_exists
evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item. * list_append (operand, operand)
- evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands. These function names are case-sensitive. * REMOVE
- Removes one or more attributes from an item. * ADD
- Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of ADD
depends on the data type of the attribute: * If the existing attribute is a number, and if Value
is also a number, then Value
is mathematically added to the existing attribute. If Value
is a negative number, then it is subtracted from the existing attribute. * If the existing data type is a set and if Value
is also a set, then Value
is added to the existing set. For example, if the attribute value is the set [1,2]
, and the ADD
action specified [3]
, then the final attribute value is [1,2,3]
. An error occurs if an ADD
action is specified for a set attribute and the attribute type specified does not match the existing set type. Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the Value
must also be a set of strings. Important: The ADD
action only supports Number and set data types. In addition, ADD
can only be used on top-level attributes, not nested attributes. * DELETE
- Deletes an element from a set. If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c]
and the DELETE
action specifies [a,c]
, then the final attribute value is [b]
. Specifying an empty set is an error. Important: The DELETE
action only supports set data types. In addition, DELETE
can only be used on top-level attributes, not nested attributes. You can have many actions in a single expression, such as the following: SET a=:value1, b=:value2 DELETE :value3, :value4, :value5
For more information on update expressions, see Modifying Items and Attributes in the Amazon DynamoDB Developer Guide .
uiExpressionAttributeValues :: Lens' UpdateItem (HashMap Text AttributeValue) Source #
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 in the Amazon DynamoDB Developer Guide .
uiAttributeUpdates :: Lens' UpdateItem (HashMap Text AttributeValueUpdate) Source #
This is a legacy parameter. Use UpdateExpression
instead. For more information, see AttributeUpdates in the Amazon DynamoDB Developer Guide .
uiReturnConsumedCapacity :: Lens' UpdateItem (Maybe ReturnConsumedCapacity) Source #
Undocumented member.
uiReturnItemCollectionMetrics :: Lens' UpdateItem (Maybe ReturnItemCollectionMetrics) Source #
Determines whether item collection metrics are returned. If set to SIZE
, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE
(the default), no statistics are returned.
uiConditionExpression :: Lens' UpdateItem (Maybe Text) Source #
A condition that must be satisfied in order for a conditional update to succeed. An expression can contain any of the following: * Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size
These function names are case-sensitive. * Comparison operators: = | <> | | | |= | BETWEEN | IN
* Logical operators: AND | OR | NOT
For more information on condition expressions, see Specifying Conditions in the Amazon DynamoDB Developer Guide .
uiConditionalOperator :: Lens' UpdateItem (Maybe ConditionalOperator) Source #
This is a legacy parameter. Use ConditionExpression
instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide .
uiExpected :: Lens' UpdateItem (HashMap Text ExpectedAttributeValue) Source #
This is a legacy parameter. Use ConditionExpression
instead. For more information, see Expected in the Amazon DynamoDB Developer Guide .
uiTableName :: Lens' UpdateItem Text Source #
The name of the table containing the item to update.
uiKey :: Lens' UpdateItem (HashMap Text AttributeValue) Source #
The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute. For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
Destructuring the Response
Creates a value of UpdateItemResponse
with the minimum fields required to make a request.
Use one of the following lenses to modify other fields as desired:
uirsItemCollectionMetrics
- Information about item collections, if any, that were affected by theUpdateItem
operation.ItemCollectionMetrics
is only returned if theReturnItemCollectionMetrics
parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response. EachItemCollectionMetrics
element consists of: *ItemCollectionKey
- The partition key value of the item collection. This is the same as the partition key value of the item itself. *SizeEstimateRangeGB
- An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit. The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.uirsConsumedCapacity
- The capacity units consumed by theUpdateItem
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 theReturnConsumedCapacity
parameter was specified. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide .uirsAttributes
- A map of attribute values as they appear before or after theUpdateItem
operation, as determined by theReturnValues
parameter. TheAttributes
map is only present ifReturnValues
was specified as something other thanNONE
in the request. Each element represents one attribute.uirsResponseStatus
- -- | The response status code.
data UpdateItemResponse Source #
Represents the output of an UpdateItem
operation.
See: updateItemResponse
smart constructor.
Instances
Response Lenses
uirsItemCollectionMetrics :: Lens' UpdateItemResponse (Maybe ItemCollectionMetrics) Source #
Information about item collections, if any, that were affected by the UpdateItem
operation. ItemCollectionMetrics
is only returned if the ReturnItemCollectionMetrics
parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response. Each ItemCollectionMetrics
element consists of: * ItemCollectionKey
- The partition key value of the item collection. This is the same as the partition key value of the item itself. * SizeEstimateRangeGB
- An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit. The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
uirsConsumedCapacity :: Lens' UpdateItemResponse (Maybe ConsumedCapacity) Source #
The capacity units consumed by the UpdateItem
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 in the Amazon DynamoDB Developer Guide .
uirsAttributes :: Lens' UpdateItemResponse (HashMap Text AttributeValue) Source #
A map of attribute values as they appear before or after the UpdateItem
operation, as determined by the ReturnValues
parameter. The Attributes
map is only present if ReturnValues
was specified as something other than NONE
in the request. Each element represents one attribute.
uirsResponseStatus :: Lens' UpdateItemResponse Int Source #
- - | The response status code.