Question

我想通过dynamoDB创建表User，其中包含一些由swagger设计的属性：

User {
   id (string, optional): UUID of User ,
   name (string, optional),
   lastLoginedAt (string, optional),
   avatar (Avatar, optional),
}

Avatar {
   avatarId (string, optional):,
   iconUri (string, optional),
   message (string, optional),
}

并希望User将在putItem之后使用json响应，如下所示：

{
"id": "string",
"name": "string",
"lastLoginedAt": "2016-06-24 15:28:26",
"avatar": {
  "avatarId": "string",
  "iconUri": "string",
  "message": "string"
},
}

我是新手Dynamodb，我仍然坚持使用create table，这里是我的代码：

$dynamodb->createTable([
'TableName' => 'User',
'AttributeDefinitions' => [
    [ 'AttributeName' => 'id', 'AttributeType' => 'S' ],
    [ 'AttributeName' => 'name', 'AttributeType' => 'S' ],
    [ 'AttributeName' => 'avatar', 'AttributeType' => 'S' ]
],
'KeySchema' => [
    [ 'AttributeName' => 'id', 'KeyType' => 'HASH' ],  
    [ 'AttributeName' => 'name', 'KeyType' => 'RANGE' ]
],
'GlobalSecondaryIndexes' => [
    [
        'IndexName' => 'avatarIndex',
        'KeySchema' => [
            [ 'AttributeName' => 'avatarId', 'KeyType' => 'HASH' ],  
            [ 'AttributeName' => 'id', 'KeyType' => 'RANGE' ] 
        ],
        'Projection' => [ 
            'ProjectionType' => 'INCLUDE',
            'NonKeyAttributes' => [ 'iconUri', 'message' ]
        ],
        'ProvisionedThroughput' => [
            'ReadCapacityUnits' => 5,
            'WriteCapacityUnits' => 5
        ]
    ]
],
'ProvisionedThroughput' => [
    'ReadCapacityUnits' => 5,
    'WriteCapacityUnits' => 5
]]);

这是错误：

local.ERROR: Error executing "CreateTable" on "http://172.18.0.5:8000"; AWS HTTP error: Client error: `POST http://172.18.0.5:8000` resulted in a `400 Bad Request` response:{"__type":"com.amazon.coral.validate#ValidationException","message":"Global Secondary Index hash key not specified in At (truncated...)
ValidationException (client): Global Secondary Index hash key not   specified in Attribute Definitons.Type unknown. - {"__type":"com.amazon.coral.validate#ValidationException","message":"Global Secondary Index hash key not specified in Attribute Definitons.Type unknown."}

感谢提前！

Answer 1

根据错误，您似乎忘记在主表中添加属性，以下代码应该可以正常工作

$dynamodb->createTable([
'TableName' => 'User',
'AttributeDefinitions' => [
    [ 'AttributeName' => 'id', 'AttributeType' => 'S' ], 
    [ 'AttributeName' => 'name', 'AttributeType' => 'S' ],
    [ 'AttributeName' => 'avatar', 'AttributeType' => 'S' ],
    [ 'AttributeName' => 'avatarId', 'AttributeType' => 'S' ], // this attribute was missing  

],
'KeySchema' => [
    [ 'AttributeName' => 'id', 'KeyType' => 'HASH' ],  
    [ 'AttributeName' => 'name', 'KeyType' => 'RANGE' ]
],
'GlobalSecondaryIndexes' => [
    [
        'IndexName' => 'avatarIndex',
        'KeySchema' => [
            [ 'AttributeName' => 'avatarId', 'KeyType' => 'HASH' ],  
            [ 'AttributeName' => 'id', 'KeyType' => 'RANGE' ] 
        ],
        'Projection' => [ 
            'ProjectionType' => 'INCLUDE',
            'NonKeyAttributes' => [ 'iconUri', 'message' ]
        ],
        'ProvisionedThroughput' => [
            'ReadCapacityUnits' => 5,
            'WriteCapacityUnits' => 5
        ]
    ]
],
'ProvisionedThroughput' => [
    'ReadCapacityUnits' => 5,
    'WriteCapacityUnits' => 5
]]);

您需要在主表属性定义中包含GSI的哈希和范围属性。除了Lokesh提到的内容之外，您还可以为您的头像对象使用StringSet数据类型。

希望有所帮助。

Answer 2

在Dynamodb中，您无法保存复杂对象。在您的案例头像中，您无法将其另存为复杂对象。

但是您可以将头像对象JSON保存为字符串，而头像只会保存一个类型为字符串的列。

将任何JSON保存为字符串后，您无法在JSON中创建属性索引。

在您的情况下，您不应该以json格式保存头像。您可以创建avatarId，avatarIconUri和avatarMessage等列。

{
"id": "string",
"name": "string",
"lastLoginedAt": "2016-06-24 15:28:26",
"avatarId": "string",
"avatarIconUri": "string",
"avatarMessage": "string"
}



GlobalSecondaryIndexes' => [
    [
        'IndexName' => 'avatarIndex',
        'KeySchema' => [
            [ 'AttributeName' => 'avatarId', 'KeyType' => 'HASH' ],  
            [ 'AttributeName' => 'id', 'KeyType' => 'RANGE' ] 
        ],
        'Projection' => [ 
            'ProjectionType' => 'INCLUDE',
            'NonKeyAttributes' => [ 'avatarIconUri', 'avatarMessage' ]
        ],
        'ProvisionedThroughput' => [
            'ReadCapacityUnits' => 5,
            'WriteCapacityUnits' => 5
        ]
    ]
],

如何使用全局二级索引创建表dynamodb

2 个答案: