我正在使用适用于 PHP 3.x 的 AWS 开发工具包
对 BatchWriteItem 的单次调用最多可写入 16 MB 的数据，其中可包含多达 25 个放置或删除请求。要写入的单个项目最大可达 400 KB。
$result = $dynamodbClient->batchWriteItem([
'RequestItems' => [
$tableName => [
[
'PutRequest' => [
'Item' => [
'Id' => ['N' => '1'],
'AlbumTitle' => [
'S' => 'Somewhat Famous',
],
'Artist' => [
'S' => 'No One You Know',
],
'SongTitle' => [
'S' => 'Call Me Today',
],
],
],
],
],
],
]);
对于单个项目来说，它工作正常。我怎样才能写超过25条。
要写入超过 25 个项目，您必须重复调用 BatchWriteItem，从集合中添加项目，一次 25 个。
沿着这些思路（伪代码）：
requests = []; // use an array to stage your put item requests
foreach(item in SourceCollection) {
addItem(item, requests); // add this item to the array
if(count(requests) == 25) { // when you have 25 ready..
// result = dynamodbClient->batchWriteItem(...)
requests = []; // clean up the array of put item requests
// handle the failed items from the result object
}
}
确保通过将每个batchWriteItem结果重新添加回请求来处理失败的项目
这是我的 lambda 函数的方法：
exports.handler = (event, context, callback) => {
console.log(`EVENT: ${JSON.stringify(event)}`);
var AWS = require('aws-sdk');
AWS.config.update({ region: process.env.REGION })
var docClient = new AWS.DynamoDB.DocumentClient();
const {data, table, cb} = JSON.parse(event.body);
console.log('{data, table, cb}:', {data, table, cb});
// Build the batches
var batches = [];
var current_batch = [];
var item_count = 0;
for (var i = 0; i < data.length; i++) {
// Add the item to the current batch
item_count++
current_batch.push({
PutRequest: {
Item: data[i],
},
})
// If we've added 25 items, add the current batch to the batches array
// and reset it
if (item_count % 25 === 0) {
batches.push(current_batch)
current_batch = []
}
}
// Add the last batch if it has records and is not equal to 25
if (current_batch.length > 0 && current_batch.length !== 25) {
batches.push(current_batch)
}
// Handler for the database operations
var completed_requests = 0
var errors = false
function requestHandler (request) {
console.log('in the handler: ', request)
return function (err, data) {
// Increment the completed requests
completed_requests++;
// Set the errors flag
errors = (errors) ? true : err;
// Log the error if we got one
if(err) {
console.error(JSON.stringify(err, null, 2));
console.error("Request that caused database error:");
console.error(JSON.stringify(request, null, 2));
callback(err);
}else {
var response = {
statusCode: 200,
headers: {
'Content-Type': 'application/json',
'Access-Control-Allow-Methods': 'GET,POST,OPTIONS',
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Credentials': true
},
body: JSON.stringify(data),
isBase64Encoded: false
};
console.log(`success: returned ${data}`);
callback(null, response);
}
// Make the callback if we've completed all the requests
if(completed_requests === batches.length) {
cb(errors);
}
}
}
// Make the requests
var params;
for (var j = 0; j < batches.length; j++) {
// Items go in params.RequestItems.id array
// Format for the items is {PutRequest: {Item: ITEM_OBJECT}}
params = '{"RequestItems": {"' + table + '": []}}'
params = JSON.parse(params)
params.RequestItems[table] = batches[j]
console.log('before db.batchWrite: ', params)
// Perform the batchWrite operation
docClient.batchWrite(params, requestHandler(params))
}
};
dealspoondBatchWrite
我正在使用以下代码使用batchWriteItem添加数据。有没有更好的办法请指教。
// Build the batches
$albums= "// collection of album json";
$batches = [];
$current_batch = [];
$item_count = 0;
foreach ($albums as $album) {
// Add the item to the current batch
$item_count++;
$json = json_encode($album);
$data['PutRequest'] = array('Item' => $marshaler->marshalJson($json));
array_push($current_batch, $data);
// If we've added 25 items, add the current batch to the batches array
// and reset it
if ($item_count % 25 == 0) {
array_push($batches, $current_batch);
$current_batch = [];
}
}
// Handler for the database operations
// Add the last batch if it has records and is not equal to 25
if (count($current_batch) > 0 && count($current_batch) != 25) {
array_push($batches, array_values($current_batch));
}
//batches.push(current_batch);
// Handler for the database operations
$completed_requests = 0;
$errors = false;
$batch_count = 0;
foreach ($batches as $batch) {
try {
$batch_count++;
$params = array('RequestItems' => array($tableName => $batch), 'ReturnConsumedCapacity' => 'TOTAL', 'ReturnItemCollectionMetrics' => 'SIZE');
$response = $dynamodb->batchWriteItem($params);
echo "Album $batch_count Added." . "<br>";
echo "<pre>";
// print_r($params);
print_r($response);
echo "</pre>";
}
catch (DynamoDbException $e) {
echo "Unable to add movie:\n";
echo $e->getMessage() . "\n";
// break;
}
}
array_chunk$items = [
'PutRequest' => [
'Item' => [
'Id' => ['N' => '1'],
'AlbumTitle' => [
'S' => 'Somewhat Famous',
],
'Artist' => [
'S' => 'No One You Know',
],
'SongTitle' => [
'S' => 'Call Me Today',
],
],
],
];
foreach (array_chunk($items, 25) as $chunk) {
try {
$response = $dynamoDbClient->batchWriteItem([
'RequestItems' => [
$tableName => $chunk
]
]);
} catch (Exception $e) {
// Log the exception and handle it
}
}
确保在
$dynamoDbClient$tableNameforeach