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 delete_item
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.
dynamodb_delete_item(TableName, Key, Expected, ConditionalOperator,
ReturnValues, ReturnConsumedCapacity, ReturnItemCollectionMetrics,
ConditionExpression, ExpressionAttributeNames,
ExpressionAttributeValues)A list with the following syntax:
list(
Attributes = list(
list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
)
),
ConsumedCapacity = list(
TableName = "string",
CapacityUnits = 123.0,
ReadCapacityUnits = 123.0,
WriteCapacityUnits = 123.0,
Table = list(
ReadCapacityUnits = 123.0,
WriteCapacityUnits = 123.0,
CapacityUnits = 123.0
),
LocalSecondaryIndexes = list(
list(
ReadCapacityUnits = 123.0,
WriteCapacityUnits = 123.0,
CapacityUnits = 123.0
)
),
GlobalSecondaryIndexes = list(
list(
ReadCapacityUnits = 123.0,
WriteCapacityUnits = 123.0,
CapacityUnits = 123.0
)
)
),
ItemCollectionMetrics = list(
ItemCollectionKey = list(
list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
)
),
SizeEstimateRangeGB = list(
123.0
)
)
)
[required] The name of the table from which to delete the item.
[required] 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 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.
This is a legacy parameter. Use ConditionExpression instead. For more
information, see
Expected
in the Amazon DynamoDB Developer Guide.
This is a legacy parameter. Use ConditionExpression instead. For more
information, see
ConditionalOperator
in the Amazon DynamoDB Developer Guide.
Use ReturnValues if you want to get the item attributes as they
appeared before they were deleted. For
delete_item, 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.
The ReturnValues parameter is used by several DynamoDB operations;
however, delete_item does not recognize any
values other than NONE or ALL_OLD.
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.
A condition that must be satisfied in order for a conditional
delete_item 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 about condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.
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.
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.
svc$delete_item(
TableName = "string",
Key = list(
list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
)
),
Expected = list(
list(
Value = list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
),
Exists = TRUE|FALSE,
ComparisonOperator = "EQ"|"NE"|"IN"|"LE"|"LT"|"GE"|"GT"|"BETWEEN"|"NOT_NULL"|"NULL"|"CONTAINS"|"NOT_CONTAINS"|"BEGINS_WITH",
AttributeValueList = list(
list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
)
)
)
),
ConditionalOperator = "AND"|"OR",
ReturnValues = "NONE"|"ALL_OLD"|"UPDATED_OLD"|"ALL_NEW"|"UPDATED_NEW",
ReturnConsumedCapacity = "INDEXES"|"TOTAL"|"NONE",
ReturnItemCollectionMetrics = "SIZE"|"NONE",
ConditionExpression = "string",
ExpressionAttributeNames = list(
"string"
),
ExpressionAttributeValues = list(
list(
S = "string",
N = "string",
B = raw,
SS = list(
"string"
),
NS = list(
"string"
),
BS = list(
raw
),
M = list(
list()
),
L = list(
list()
),
NULL = TRUE|FALSE,
BOOL = TRUE|FALSE
)
)
)
if (FALSE) {
# This example deletes an item from the Music table.
svc$delete_item(
Key = list(
Artist = list(
S = "No One You Know"
),
SongTitle = list(
S = "Scared of My Shadow"
)
),
TableName = "Music"
)
}
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