如何在 Nodejs 中为 DynamoDB PartiQL 指定参数

Question

我想在 NodeJs 中使用 PartiQL 在 DynamoDb 上执行 SELECT 查询，但出现错误。

简单的语句没有问题。

    const r = await client.send(
      new ExecuteStatementCommand({
          Statement: `SELECT * FROM Users WHERE userId in ['abcd1234']`
      })
    )

但是当尝试执行带有参数的语句时，我收到了错误。

代码

    const r2 = await client.send(
      new ExecuteStatementCommand({
          Statement: `SELECT * FROM Users WHERE userId in ?`,
          Parameters: [
            ['abcd1234']
          ]
      })
    )

错误

{
  "errorType": "ValidationException",
  "errorMessage": "1 validation error detected: Value '[]' at 'parameters' failed to satisfy constraint: Member must have length greater than or equal to 1",
  "trace": [
    "ValidationException: 1 validation error detected: Value '[]' at 'parameters' failed to satisfy constraint: Member must have length greater than or equal to 1",
    "    at deserializeAws_json1_0ExecuteStatementCommandError (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:2202:41)",
    "    at processTicksAndRejections (internal/process/task_queues.js:97:5)",
    "    at async /var/task/node_modules/@aws-sdk/middleware-serde/dist/cjs/deserializerMiddleware.js:6:20",
    "    at async /var/task/node_modules/@aws-sdk/middleware-signing/dist/cjs/middleware.js:12:24",
    "    at async StandardRetryStrategy.retry (/var/task/node_modules/@aws-sdk/middleware-retry/dist/cjs/defaultStrategy.js:56:46)",
    "    at async /var/task/node_modules/@aws-sdk/middleware-logger/dist/cjs/loggerMiddleware.js:6:22",
    "    at async /var/task/node_modules/@aws-sdk/lib-dynamodb/dist/cjs/commands/ExecuteStatementCommand.js:29:26",
    "    at async Runtime.handler (/var/task/save.js:39:16)"
  ]
}

有没有人有解决办法？

这是完整代码。

  const client = DynamoDBDocumentClient.from(
    new DynamoDBClient({})
  );

    // this works
    const r = await client.send(
      new ExecuteStatementCommand({
          Statement: `SELECT * FROM Users WHERE userId in ['abcd1234']`
      })
    )

    // this gets an error
    const r2 = await client.send(
      new ExecuteStatementCommand({
          Statement: `SELECT * FROM Users WHERE userId in ?`,
          Parameters: [
            ['abcd1234']
          ]
      })
    )

Answer 1

据我所知，不太可能做你想做的事情（将一个字符串数组作为准备好的语句中的参数传递给 IN 运算符的右侧参数😅）。

看来你能做的最好的就是：

executeStatement({
  Statement: `SELECT * FROM Users WHERE userId in [?, ?]`,
  Parameters: [
    {"S": "firstId"},
    {"S": "secondId"}, 
    // ...etc.
  ]
})

请注意，

Parameters

属性采用键值对数组。每个参数属性值都被描述为名称-值对。名称是数据类型（例如

"S"

表示字符串），值是数据本身（例如用户 ID。）

就您而言，如果您有用户列表，您可以执行以下操作：

const users = [
  { id: "id-1" },
  { id: "id-2" },
  { id: "id-3" },
]

executeStatement({
  Statement: `SELECT * FROM Users WHERE userId in [${users.map(() => '?').join(',')}]`,
  Parameters: 
    users.map(user => ({"S": user.id}))  
})

请注意，您可以传递的参数数量可能有一些上限，但我在任何地方都找不到这个数字的记录。

Answer 2

// Before
SELECT * FROM Users WHERE userId in ?

// After
SELECT * FROM Users WHERE userId in '?'

Answer 3

当我在 Python 中使用 boto3 客户端尝试此操作时，它对我有用的方式是直接传递参数值，而不是它们在文档中显示的类型/值映射

executeStatement({
  Statement: `SELECT * FROM Users WHERE userId in (?,?,?)`,
  Parameters: [
     'id-1',
     'id-2',
     'id-3'
  ]
})

当我通过

[{"S": "id-1"}, {"S": "id-2"}, {"S": "id-3"}]

我得到

An error occurred (ValidationException) when calling the ExecuteStatement operation: Key value must be of type S, N, or B. Key name: accessionNumber, Key type: M