{-# LANGUAGE DataKinds #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE LambdaCase #-} {-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE RecordWildCards #-} {-# LANGUAGE TypeFamilies #-} {-# OPTIONS_GHC -fno-warn-unused-imports #-} -- Module : Network.AWS.DynamoDB.DeleteItem -- Copyright : (c) 2013-2014 Brendan Hay <brendan.g.hay@gmail.com> -- License : This Source Code Form is subject to the terms of -- the Mozilla Public License, v. 2.0. -- A copy of the MPL can be found in the LICENSE file or -- you can obtain it at http://mozilla.org/MPL/2.0/. -- Maintainer : Brendan Hay <brendan.g.hay@gmail.com> -- Stability : experimental -- Portability : non-portable (GHC extensions) -- -- Derived from AWS service descriptions, licensed under Apache 2.0. -- | Deletes a single item in a table by primary key. You can perform a -- conditional delete operation that deletes the item if it exists, or if it has -- an expected attribute value. -- -- In addition to deleting an item, you can also return the item's attribute -- values in the same operation, using the /ReturnValues/ parameter. -- -- Unless you specify conditions, the /DeleteItem/ is an idempotent operation; -- running it multiple times on the same item or attribute does /not/ result in an -- error response. -- -- Conditional deletes are useful for deleting items only if specific -- conditions are met. If those conditions are met, DynamoDB performs the -- delete. Otherwise, the item is not deleted. -- -- <http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_DeleteItem.html> module Network.AWS.DynamoDB.DeleteItem ( -- * Request DeleteItem -- ** Request constructor , deleteItem -- ** Request lenses , diConditionExpression , diConditionalOperator , diExpected , diExpressionAttributeNames , diExpressionAttributeValues , diKey , diReturnConsumedCapacity , diReturnItemCollectionMetrics , diReturnValues , diTableName -- * Response , DeleteItemResponse -- ** Response constructor , deleteItemResponse -- ** Response lenses , dirAttributes , dirConsumedCapacity , dirItemCollectionMetrics ) where import Network.AWS.Prelude import Network.AWS.Request.JSON import Network.AWS.DynamoDB.Types import qualified GHC.Exts data DeleteItem = DeleteItem { _diConditionExpression :: Maybe Text , _diConditionalOperator :: Maybe ConditionalOperator , _diExpected :: Map Text ExpectedAttributeValue , _diExpressionAttributeNames :: Map Text Text , _diExpressionAttributeValues :: Map Text AttributeValue , _diKey :: Map Text AttributeValue , _diReturnConsumedCapacity :: Maybe ReturnConsumedCapacity , _diReturnItemCollectionMetrics :: Maybe ReturnItemCollectionMetrics , _diReturnValues :: Maybe ReturnValue , _diTableName :: Text } deriving (Eq, Show) -- | 'DeleteItem' constructor. -- -- The fields accessible through corresponding lenses are: -- -- * 'diConditionExpression' @::@ 'Maybe' 'Text' -- -- * 'diConditionalOperator' @::@ 'Maybe' 'ConditionalOperator' -- -- * 'diExpected' @::@ 'HashMap' 'Text' 'ExpectedAttributeValue' -- -- * 'diExpressionAttributeNames' @::@ 'HashMap' 'Text' 'Text' -- -- * 'diExpressionAttributeValues' @::@ 'HashMap' 'Text' 'AttributeValue' -- -- * 'diKey' @::@ 'HashMap' 'Text' 'AttributeValue' -- -- * 'diReturnConsumedCapacity' @::@ 'Maybe' 'ReturnConsumedCapacity' -- -- * 'diReturnItemCollectionMetrics' @::@ 'Maybe' 'ReturnItemCollectionMetrics' -- -- * 'diReturnValues' @::@ 'Maybe' 'ReturnValue' -- -- * 'diTableName' @::@ 'Text' -- deleteItem :: Text -- ^ 'diTableName' -> DeleteItem deleteItem p1 = DeleteItem { _diTableName = p1 , _diKey = mempty , _diExpected = mempty , _diConditionalOperator = Nothing , _diReturnValues = Nothing , _diReturnConsumedCapacity = Nothing , _diReturnItemCollectionMetrics = Nothing , _diConditionExpression = Nothing , _diExpressionAttributeNames = mempty , _diExpressionAttributeValues = mempty } -- | A condition that must be satisfied in order for a conditional /DeleteItem/ to -- succeed. -- -- An expression can contain any of the following: -- -- Boolean functions: 'ATTRIBUTE_EXIST | CONTAINS | BEGINS_WITH' -- -- Comparison operators: ' = | <> | < | > | <= | >= | BETWEEN | IN' -- -- Logical operators: 'NOT | AND | OR' -- -- diConditionExpression :: Lens' DeleteItem (Maybe Text) diConditionExpression = lens _diConditionExpression (\s a -> s { _diConditionExpression = a }) -- | There is a newer parameter available. Use /ConditionExpression/ instead. Note -- that if you use /ConditionalOperator/ and / ConditionExpression / at the same -- time, DynamoDB will return a /ValidationException/ exception. -- -- This parameter does not support lists or maps. -- -- A logical operator to apply to the conditions in the /Expected/ map: -- -- 'AND' - If all of the conditions evaluate to true, then the entire map -- evaluates to true. -- -- 'OR' - If at least one of the conditions evaluate to true, then the entire map -- evaluates to true. -- -- If you omit /ConditionalOperator/, then 'AND' is the default. -- -- The operation will succeed only if the entire map evaluates to true. diConditionalOperator :: Lens' DeleteItem (Maybe ConditionalOperator) diConditionalOperator = lens _diConditionalOperator (\s a -> s { _diConditionalOperator = a }) -- | There is a newer parameter available. Use /ConditionExpression/ instead. Note -- that if you use /Expected/ and / ConditionExpression / at the same time, DynamoDB -- will return a /ValidationException/ exception. -- -- This parameter does not support lists or maps. -- -- A map of attribute/condition pairs. /Expected/ provides a conditional block -- for the /DeleteItem/ operation. -- -- Each element of /Expected/ consists of an attribute name, a comparison -- operator, and one or more values. DynamoDB compares the attribute with the -- value(s) you supplied, using the comparison operator. For each /Expected/ -- element, the result of the evaluation is either true or false. -- -- If you specify more than one element in the /Expected/ map, then by default -- all of the conditions must evaluate to true. In other words, the conditions -- are ANDed together. (You can use the /ConditionalOperator/ parameter to OR the -- conditions instead. If you do this, then at least one of the conditions must -- evaluate to true, rather than all of them.) -- -- If the /Expected/ map evaluates to true, then the conditional operation -- succeeds; otherwise, it fails. -- -- /Expected/ contains the following: -- -- /AttributeValueList/ - One or more values to evaluate against the supplied -- attribute. The number of values in the list depends on the /ComparisonOperator/ -- being used. -- -- For type Number, value comparisons are numeric. -- -- String value comparisons for greater than, equals, or less than are based on -- ASCII character code values. For example, 'a' is greater than 'A', and 'aa' is -- greater than 'B'. For a list of code values, see <http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>. -- -- For type Binary, DynamoDB treats each byte of the binary data as unsigned -- when it compares binary values, for example when evaluating query expressions. -- -- /ComparisonOperator/ - A comparator for evaluating attributes in the /AttributeValueList/. When performing the comparison, DynamoDB uses strongly consistent reads. -- -- The following comparison operators are available: -- -- 'EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS |BEGINS_WITH | IN | BETWEEN' -- -- The following are descriptions of each comparison operator. -- -- 'EQ' : Equal. 'EQ' is supported for all datatypes, including lists and maps. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, Binary, String Set, Number Set, or Binary Set. If an item -- contains an /AttributeValue/ element of a different type than the one specified -- in the request, the value does not match. For example, '{"S":"6"}' does not -- equal '{"N":"6"}'. Also, '{"N":"6"}' does not equal '{"NS":["6", "2", "1"]}'. -- -- -- -- 'NE' : Not equal. 'NE' is supported for all datatypes, including lists and -- maps. -- -- /AttributeValueList/ can contain only one /AttributeValue/ of type String, -- Number, Binary, String Set, Number Set, or Binary Set. If an item contains an /AttributeValue/ of a different type than the one specified in the request, the -- value does not match. For example, '{"S":"6"}' does not equal '{"N":"6"}'. Also, '{"N":"6"}' does not equal '{"NS":["6", "2", "1"]}'. -- -- -- -- 'LE' : Less than or equal. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, or Binary (not a set type). If an item contains an /AttributeValue/ element of a different type than the one specified in the request, the value -- does not match. For example, '{"S":"6"}' does not equal '{"N":"6"}'. Also, '{"N":"6"}' does not compare to '{"NS":["6", "2", "1"]}'. -- -- -- -- 'LT' : Less than. -- -- /AttributeValueList/ can contain only one /AttributeValue/ of type String, -- Number, or Binary (not a set type). If an item contains an /AttributeValue/ -- element of a different type than the one specified in the request, the value -- does not match. For example, '{"S":"6"}' does not equal '{"N":"6"}'. Also, '{"N":"6"}' does not compare to '{"NS":["6", "2", "1"]}'. -- -- -- -- 'GE' : Greater than or equal. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, or Binary (not a set type). If an item contains an /AttributeValue/ element of a different type than the one specified in the request, the value -- does not match. For example, '{"S":"6"}' does not equal '{"N":"6"}'. Also, '{"N":"6"}' does not compare to '{"NS":["6", "2", "1"]}'. -- -- -- -- 'GT' : Greater than. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, or Binary (not a set type). If an item contains an /AttributeValue/ element of a different type than the one specified in the request, the value -- does not match. For example, '{"S":"6"}' does not equal '{"N":"6"}'. Also, '{"N":"6"}' does not compare to '{"NS":["6", "2", "1"]}'. -- -- -- -- 'NOT_NULL' : The attribute exists. 'NOT_NULL' is supported for all datatypes, -- including lists and maps. -- -- 'NULL' : The attribute does not exist. 'NULL' is supported for all datatypes, -- including lists and maps. -- -- 'CONTAINS' : Checks for a subsequence, or value in a set. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, or Binary (not a set type). If the target attribute of the -- comparison is of type String, then the operator checks for a substring match. -- If the target attribute of the comparison is of type Binary, then the -- operator looks for a subsequence of the target that matches the input. If the -- target attribute of the comparison is a set ("'SS'", "'NS'", or "'BS'"), then the -- operator evaluates to true if it finds an exact match with any member of the -- set. -- -- CONTAINS is supported for lists: When evaluating "'a CONTAINS b'", "'a'" can be -- a list; however, "'b'" cannot be a set, a map, or a list. -- -- 'NOT_CONTAINS' : Checks for absence of a subsequence, or absence of a value -- in a set. -- -- /AttributeValueList/ can contain only one /AttributeValue/ element of type -- String, Number, or Binary (not a set type). If the target attribute of the -- comparison is a String, then the operator checks for the absence of a -- substring match. If the target attribute of the comparison is Binary, then -- the operator checks for the absence of a subsequence of the target that -- matches the input. If the target attribute of the comparison is a set ("'SS'", "'NS'", or "'BS'"), then the operator evaluates to true if it /does not/ find an -- exact match with any member of the set. -- -- NOT_CONTAINS is supported for lists: When evaluating "'a NOT CONTAINS b'", "'a'" -- can be a list; however, "'b'" cannot be a set, a map, or a list. -- -- 'BEGINS_WITH' : Checks for a prefix. -- -- /AttributeValueList/ can contain only one /AttributeValue/ of type String or -- Binary (not a Number or a set type). The target attribute of the comparison -- must be of type String or Binary (not a Number or a set type). -- -- -- -- 'IN' : Checks for matching elements within two sets. -- -- /AttributeValueList/ can contain one or more /AttributeValue/ elements of type -- String, Number, or Binary (not a set type). These attributes are compared -- against an existing set type attribute of an item. If any elements of the -- input set are present in the item attribute, the expression evaluates to true. -- -- 'BETWEEN' : Greater than or equal to the first value, and less than or equal -- to the second value. -- -- /AttributeValueList/ must contain two /AttributeValue/ elements of the same -- type, either String, Number, or Binary (not a set type). A target attribute -- matches if the target value is greater than, or equal to, the first element -- and less than, or equal to, the second element. If an item contains an /AttributeValue/ element of a different type than the one specified in the request, the value -- does not match. For example, '{"S":"6"}' does not compare to '{"N":"6"}'. Also, '{"N":"6"}' does not compare to '{"NS":["6", "2", "1"]}' -- -- For usage examples of /AttributeValueList/ and /ComparisonOperator/, see <http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.html Legacy Conditional Parameters> in the /Amazon DynamoDB Developer Guide/. -- -- For backward compatibility with previous DynamoDB releases, the following -- parameters can be used instead of /AttributeValueList/ and /ComparisonOperator/: -- -- /Value/ - A value for DynamoDB to compare with an attribute. -- -- /Exists/ - A Boolean value that causes DynamoDB to evaluate the value before -- attempting the conditional operation: -- -- If /Exists/ is 'true', DynamoDB will check to see if that attribute value -- already exists in the table. If it is found, then the condition evaluates to -- true; otherwise the condition evaluate to false. -- -- If /Exists/ is 'false', DynamoDB assumes that the attribute value does /not/ -- exist in the table. If in fact the value does not exist, then the assumption -- is valid and the condition evaluates to true. If the value is found, despite -- the assumption that it does not exist, the condition evaluates to false. -- -- The /Value/ and /Exists/ parameters are incompatible with /AttributeValueList/ -- and /ComparisonOperator/. Note that if you use both sets of parameters at once, -- DynamoDB will return a /ValidationException/ exception. diExpected :: Lens' DeleteItem (HashMap Text ExpectedAttributeValue) diExpected = lens _diExpected (\s a -> s { _diExpected = a }) . _Map -- | One or more substitution tokens for simplifying complex expressions. The -- following are some use cases for an /ExpressionAttributeNames/ value: -- -- To shorten an attribute name that is very long or unwieldy in an -- expression. -- -- 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 expression: -- -- 'order.customerInfo.LastName = "Smith" OR order.customerInfo.LastName ="Jones"' -- -- Now suppose that you specified the following for /ExpressionAttributeNames/: -- -- '{"n":"order.customerInfo.LastName"}' -- -- The expression can now be simplified as follows: -- -- '#n = "Smith" OR #n = "Jones"' -- diExpressionAttributeNames :: Lens' DeleteItem (HashMap Text Text) diExpressionAttributeNames = lens _diExpressionAttributeNames (\s a -> s { _diExpressionAttributeNames = a }) . _Map -- | One or more values that can be substituted in an expression. -- -- Use the : character in an expression to dereference an attribute value. For -- example, consider the following expression: -- -- 'ProductStatus IN ("Available","Backordered","Discontinued")' -- -- Now suppose that you specified the following for /ExpressionAttributeValues/: -- -- '{ "a":{"S":"Available"}, "b":{"S":"Backordered"}, "d":{"S":"Discontinued"} }' -- -- The expression can now be simplified as follows: -- -- 'ProductStatus IN (:a,:b,:c)' -- diExpressionAttributeValues :: Lens' DeleteItem (HashMap Text AttributeValue) diExpressionAttributeValues = lens _diExpressionAttributeValues (\s a -> s { _diExpressionAttributeValues = a }) . _Map -- | A map of attribute names to /AttributeValue/ objects, representing the primary -- key of the item to delete. -- -- For the primary key, you must provide all of the attributes. For example, -- with a hash type primary key, you only need to specify the hash attribute. -- For a hash-and-range type primary key, you must specify both the hash -- attribute and the range attribute. diKey :: Lens' DeleteItem (HashMap Text AttributeValue) diKey = lens _diKey (\s a -> s { _diKey = a }) . _Map diReturnConsumedCapacity :: Lens' DeleteItem (Maybe ReturnConsumedCapacity) diReturnConsumedCapacity = lens _diReturnConsumedCapacity (\s a -> s { _diReturnConsumedCapacity = a }) -- | A value that 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. diReturnItemCollectionMetrics :: Lens' DeleteItem (Maybe ReturnItemCollectionMetrics) diReturnItemCollectionMetrics = lens _diReturnItemCollectionMetrics (\s a -> s { _diReturnItemCollectionMetrics = a }) -- | Use /ReturnValues/ if you want to get the item attributes as they appeared -- before they were deleted. For /DeleteItem/, 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' - The content of the old item is returned. -- -- diReturnValues :: Lens' DeleteItem (Maybe ReturnValue) diReturnValues = lens _diReturnValues (\s a -> s { _diReturnValues = a }) -- | The name of the table from which to delete the item. diTableName :: Lens' DeleteItem Text diTableName = lens _diTableName (\s a -> s { _diTableName = a }) data DeleteItemResponse = DeleteItemResponse { _dirAttributes :: Map Text AttributeValue , _dirConsumedCapacity :: Maybe ConsumedCapacity , _dirItemCollectionMetrics :: Maybe ItemCollectionMetrics } deriving (Eq, Show) -- | 'DeleteItemResponse' constructor. -- -- The fields accessible through corresponding lenses are: -- -- * 'dirAttributes' @::@ 'HashMap' 'Text' 'AttributeValue' -- -- * 'dirConsumedCapacity' @::@ 'Maybe' 'ConsumedCapacity' -- -- * 'dirItemCollectionMetrics' @::@ 'Maybe' 'ItemCollectionMetrics' -- deleteItemResponse :: DeleteItemResponse deleteItemResponse = DeleteItemResponse { _dirAttributes = mempty , _dirConsumedCapacity = Nothing , _dirItemCollectionMetrics = Nothing } -- | A map of attribute names to /AttributeValue/ objects, representing the item as -- it appeared before the /DeleteItem/ operation. This map appears in the response -- only if /ReturnValues/ was specified as 'ALL_OLD' in the request. dirAttributes :: Lens' DeleteItemResponse (HashMap Text AttributeValue) dirAttributes = lens _dirAttributes (\s a -> s { _dirAttributes = a }) . _Map dirConsumedCapacity :: Lens' DeleteItemResponse (Maybe ConsumedCapacity) dirConsumedCapacity = lens _dirConsumedCapacity (\s a -> s { _dirConsumedCapacity = a }) -- | Information about item collections, if any, that were affected by the -- operation. /ItemCollectionMetrics/ is only returned if the request asked for -- it. 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 hash key value of the item collection. This is the -- same as the hash key of the item. -- -- /SizeEstimateRange/ - 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. -- -- dirItemCollectionMetrics :: Lens' DeleteItemResponse (Maybe ItemCollectionMetrics) dirItemCollectionMetrics = lens _dirItemCollectionMetrics (\s a -> s { _dirItemCollectionMetrics = a }) instance ToPath DeleteItem where toPath = const "/" instance ToQuery DeleteItem where toQuery = const mempty instance ToHeaders DeleteItem instance ToJSON DeleteItem where toJSON DeleteItem{..} = object [ "TableName" .= _diTableName , "Key" .= _diKey , "Expected" .= _diExpected , "ConditionalOperator" .= _diConditionalOperator , "ReturnValues" .= _diReturnValues , "ReturnConsumedCapacity" .= _diReturnConsumedCapacity , "ReturnItemCollectionMetrics" .= _diReturnItemCollectionMetrics , "ConditionExpression" .= _diConditionExpression , "ExpressionAttributeNames" .= _diExpressionAttributeNames , "ExpressionAttributeValues" .= _diExpressionAttributeValues ] instance AWSRequest DeleteItem where type Sv DeleteItem = DynamoDB type Rs DeleteItem = DeleteItemResponse request = post "DeleteItem" response = jsonResponse instance FromJSON DeleteItemResponse where parseJSON = withObject "DeleteItemResponse" $ \o -> DeleteItemResponse <$> o .:? "Attributes" .!= mempty <*> o .:? "ConsumedCapacity" <*> o .:? "ItemCollectionMetrics"