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# Aggiorna i dati DynamoDB utilizzando le istruzioni PartiQL UPDATE con un SDK AWS
<a name="example_dynamodb_PartiQLUpdate_section"></a>

L’esempio di codice seguente mostra come aggiornare i dati mediante le istruzioni PartiQL UPDATE.

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#### [ JavaScript ]

**SDK per JavaScript (v3)**  
Aggiorna gli elementi in una tabella DynamoDB utilizzando le istruzioni PartiQL UPDATE con. AWS SDK per JavaScript  

```
/**
 * This example demonstrates how to update items in a DynamoDB table using PartiQL.
 * It shows different ways to update documents with various index types.
 */
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
  DynamoDBDocumentClient,
  ExecuteStatementCommand,
  BatchExecuteStatementCommand,
} from "@aws-sdk/lib-dynamodb";

/**
 * Update a single attribute of an item using PartiQL.
 * 
 * @param tableName - The name of the DynamoDB table
 * @param partitionKeyName - The name of the partition key attribute
 * @param partitionKeyValue - The value of the partition key
 * @param attributeName - The name of the attribute to update
 * @param attributeValue - The new value for the attribute
 * @returns The response from the ExecuteStatementCommand
 */
export const updateSingleAttribute = async (
  tableName: string,
  partitionKeyName: string,
  partitionKeyValue: string | number,
  attributeName: string,
  attributeValue: any
) => {
  const client = new DynamoDBClient({});
  const docClient = DynamoDBDocumentClient.from(client);

  const params = {
    Statement: `UPDATE "${tableName}" SET ${attributeName} = ? WHERE ${partitionKeyName} = ?`,
    Parameters: [attributeValue, partitionKeyValue],
  };

  try {
    const data = await docClient.send(new ExecuteStatementCommand(params));
    console.log("Item updated successfully");
    return data;
  } catch (err) {
    console.error("Error updating item:", err);
    throw err;
  }
};

/**
 * Update multiple attributes of an item using PartiQL.
 * 
 * @param tableName - The name of the DynamoDB table
 * @param partitionKeyName - The name of the partition key attribute
 * @param partitionKeyValue - The value of the partition key
 * @param attributeUpdates - Object containing attribute names and their new values
 * @returns The response from the ExecuteStatementCommand
 */
export const updateMultipleAttributes = async (
  tableName: string,
  partitionKeyName: string,
  partitionKeyValue: string | number,
  attributeUpdates: Record<string, any>
) => {
  const client = new DynamoDBClient({});
  const docClient = DynamoDBDocumentClient.from(client);

  // Create SET clause for each attribute
  const setClause = Object.keys(attributeUpdates)
    .map((attr, index) => `${attr} = ?`)
    .join(", ");

  // Create parameters array with attribute values followed by the partition key value
  const parameters = [...Object.values(attributeUpdates), partitionKeyValue];

  const params = {
    Statement: `UPDATE "${tableName}" SET ${setClause} WHERE ${partitionKeyName} = ?`,
    Parameters: parameters,
  };

  try {
    const data = await docClient.send(new ExecuteStatementCommand(params));
    console.log("Item updated successfully");
    return data;
  } catch (err) {
    console.error("Error updating item:", err);
    throw err;
  }
};

/**
 * Update an item identified by a composite key (partition key + sort key) using PartiQL.
 * 
 * @param tableName - The name of the DynamoDB table
 * @param partitionKeyName - The name of the partition key attribute
 * @param partitionKeyValue - The value of the partition key
 * @param sortKeyName - The name of the sort key attribute
 * @param sortKeyValue - The value of the sort key
 * @param attributeName - The name of the attribute to update
 * @param attributeValue - The new value for the attribute
 * @returns The response from the ExecuteStatementCommand
 */
export const updateItemWithCompositeKey = async (
  tableName: string,
  partitionKeyName: string,
  partitionKeyValue: string | number,
  sortKeyName: string,
  sortKeyValue: string | number,
  attributeName: string,
  attributeValue: any
) => {
  const client = new DynamoDBClient({});
  const docClient = DynamoDBDocumentClient.from(client);

  const params = {
    Statement: `UPDATE "${tableName}" SET ${attributeName} = ? WHERE ${partitionKeyName} = ? AND ${sortKeyName} = ?`,
    Parameters: [attributeValue, partitionKeyValue, sortKeyValue],
  };

  try {
    const data = await docClient.send(new ExecuteStatementCommand(params));
    console.log("Item updated successfully");
    return data;
  } catch (err) {
    console.error("Error updating item:", err);
    throw err;
  }
};

/**
 * Update an item with a condition to ensure the update only happens if a condition is met.
 * 
 * @param tableName - The name of the DynamoDB table
 * @param partitionKeyName - The name of the partition key attribute
 * @param partitionKeyValue - The value of the partition key
 * @param attributeName - The name of the attribute to update
 * @param attributeValue - The new value for the attribute
 * @param conditionAttribute - The attribute to check in the condition
 * @param conditionValue - The value to compare against in the condition
 * @returns The response from the ExecuteStatementCommand
 */
export const updateItemWithCondition = async (
  tableName: string,
  partitionKeyName: string,
  partitionKeyValue: string | number,
  attributeName: string,
  attributeValue: any,
  conditionAttribute: string,
  conditionValue: any
) => {
  const client = new DynamoDBClient({});
  const docClient = DynamoDBDocumentClient.from(client);

  const params = {
    Statement: `UPDATE "${tableName}" SET ${attributeName} = ? WHERE ${partitionKeyName} = ? AND ${conditionAttribute} = ?`,
    Parameters: [attributeValue, partitionKeyValue, conditionValue],
  };

  try {
    const data = await docClient.send(new ExecuteStatementCommand(params));
    console.log("Item updated with condition successfully");
    return data;
  } catch (err) {
    console.error("Error updating item with condition:", err);
    throw err;
  }
};

/**
 * Batch update multiple items using PartiQL.
 * 
 * @param tableName - The name of the DynamoDB table
 * @param updates - Array of objects containing key and update information
 * @returns The response from the BatchExecuteStatementCommand
 */
export const batchUpdateItems = async (
  tableName: string,
  updates: Array<{
    partitionKeyName: string;
    partitionKeyValue: string | number;
    attributeName: string;
    attributeValue: any;
  }>
) => {
  const client = new DynamoDBClient({});
  const docClient = DynamoDBDocumentClient.from(client);

  // Create statements for each update
  const statements = updates.map((update) => {
    return {
      Statement: `UPDATE "${tableName}" SET ${update.attributeName} = ? WHERE ${update.partitionKeyName} = ?`,
      Parameters: [update.attributeValue, update.partitionKeyValue],
    };
  });

  const params = {
    Statements: statements,
  };

  try {
    const data = await docClient.send(new BatchExecuteStatementCommand(params));
    console.log("Items batch updated successfully");
    return data;
  } catch (err) {
    console.error("Error batch updating items:", err);
    throw err;
  }
};

/**
 * Example usage showing how to update items with different index types
 */
export const updateExamples = async () => {
  // Update a single attribute using a simple primary key
  await updateSingleAttribute("UsersTable", "userId", "user123", "email", "newemail@example.com");

  // Update multiple attributes at once
  await updateMultipleAttributes("UsersTable", "userId", "user123", {
    email: "newemail@example.com",
    name: "John Smith",
    lastLogin: new Date().toISOString(),
  });

  // Update an item with a composite key (partition key + sort key)
  await updateItemWithCompositeKey(
    "OrdersTable",
    "orderId",
    "order456",
    "productId",
    "prod789",
    "quantity",
    5
  );

  // Update with a condition
  await updateItemWithCondition(
    "UsersTable",
    "userId",
    "user123",
    "userStatus",
    "active",
    "userType",
    "premium"
  );

  // Batch update multiple items
  await batchUpdateItems("UsersTable", [
    {
      partitionKeyName: "userId",
      partitionKeyValue: "user123",
      attributeName: "lastLogin",
      attributeValue: new Date().toISOString(),
    },
    {
      partitionKeyName: "userId",
      partitionKeyValue: "user456",
      attributeName: "lastLogin",
      attributeValue: new Date().toISOString(),
    },
  ]);
};
```
+ Per informazioni dettagliate sull’API, consulta i seguenti argomenti nella *documentazione di riferimento dell’API AWS SDK per JavaScript *.
  + [BatchExecuteStatement](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/BatchExecuteStatementCommand)
  + [ExecuteStatement](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/ExecuteStatementCommand)

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Per un elenco completo delle guide per sviluppatori AWS SDK e degli esempi di codice, consulta. [Utilizzo di DynamoDB con un SDK AWS](sdk-general-information-section.md) Questo argomento include anche informazioni su come iniziare e dettagli sulle versioni precedenti dell’SDK.