import { _AttributeValue, _UnmarshalledAttributeValue } from './_AttributeValue';
/**
 * <p>For the <code>UpdateItem</code> operation, represents the attributes to be modified, the action to perform on each, and the new value for each.</p> <note> <p>You cannot use <code>UpdateItem</code> to update any primary key attributes. Instead, you will need to delete the item, and then use <code>PutItem</code> to create a new item with new attributes.</p> </note> <p>Attribute values cannot be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests with empty values will be rejected with a <code>ValidationException</code> exception.</p>
 */
export interface _AttributeValueUpdate {
    /**
     * <p>Represents the data for an attribute.</p> <p>Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.</p> <p>For more information, see <a href="http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes">Data Types</a> in the <i>Amazon DynamoDB Developer Guide</i>. </p>
     */
    Value?: _AttributeValue;
    /**
     * <p>Specifies how to perform the update. Valid values are <code>PUT</code> (default), <code>DELETE</code>, and <code>ADD</code>. The behavior depends on whether the specified primary key already exists in the table.</p> <p> <b>If an item with the specified <i>Key</i> is found in the table:</b> </p> <ul> <li> <p> <code>PUT</code> - Adds the specified attribute to the item. If the attribute already exists, it is replaced by the new value. </p> </li> <li> <p> <code>DELETE</code> - If no value is specified, the attribute and its value are removed from the item. The data type of the specified value must match the existing value's data type.</p> <p>If a <i>set</i> of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>[a,b,c]</code> and the <code>DELETE</code> action specified <code>[a,c]</code>, then the final attribute value would be <code>[b]</code>. Specifying an empty set is an error.</p> </li> <li> <p> <code>ADD</code> - If the attribute does not already exist, then the attribute and its values are added to the item. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p> <ul> <li> <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then the <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p> <note> <p> If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses 0 as the initial value.</p> <p>In addition, if you use <code>ADD</code> to update an existing item, and intend to increment or decrement an attribute value which does not yet exist, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update does not yet have an attribute named <i>itemcount</i>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway, even though it currently does not exist. DynamoDB will create the <i>itemcount</i> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <i>itemcount</i> attribute in the item, with a value of <code>3</code>.</p> </note> </li> <li> <p>If the existing data type is a set, and if the <code>Value</code> is also a set, then the <code>Value</code> is added to the existing set. (This is a <i>set</i> operation, not mathematical addition.) For example, if the attribute value was the set <code>[1,2]</code>, and the <code>ADD</code> action specified <code>[3]</code>, then the final attribute value would be <code>[1,2,3]</code>. 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. </p> <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings. The same holds true for number sets and binary sets.</p> </li> </ul> <p>This action is only valid for an existing attribute whose data type is number or is a set. Do not use <code>ADD</code> for any other data types.</p> </li> </ul> <p> <b>If no item with the specified <i>Key</i> is found:</b> </p> <ul> <li> <p> <code>PUT</code> - DynamoDB creates a new item with the specified primary key, and then adds the attribute. </p> </li> <li> <p> <code>DELETE</code> - Nothing happens; there is no attribute to delete.</p> </li> <li> <p> <code>ADD</code> - DynamoDB creates an item with the supplied primary key and number (or set of numbers) for the attribute value. The only data types allowed are number and number set; no other data types can be specified.</p> </li> </ul>
     */
    Action?: 'ADD' | 'PUT' | 'DELETE' | string;
}
export interface _UnmarshalledAttributeValueUpdate extends _AttributeValueUpdate {
    /**
     * <p>Represents the data for an attribute.</p> <p>Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.</p> <p>For more information, see <a href="http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes">Data Types</a> in the <i>Amazon DynamoDB Developer Guide</i>. </p>
     */
    Value?: _UnmarshalledAttributeValue;
}