dynamodb查询相当于“作者在哪里…”?

如果你能看一下下面 documentation ,您可能会认识到,对于keyconditionexpressions,只有以下运算符有效: EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN

所以,这里是交易-如果你想继续使用dynamodb,并且想做一些像 IN 对于关键条件表达式,您必须向dynamodb发送各种请求,每次都要单独包含一个作者,然后在您的末尾将它们组合在一起。

像这样:

// Considering that this docClient is the instance of aws-sdk configured for dynamodb

const TABLE = 'Videos';

const createParams = (author) => {
    return {
        TableName: TABLE,
        KeyConditionExpression: "author = :author",
        ExpressionAttributeValues: {
            ":author": author
        }
    };
}

const queryPromise = (params) => {
    return new Promise((resolve, reject) => {
        docClient.query(params, function (err, data) {
            if (err) {
                reject(err);
            } else {
                resolve(data);
            }
        });
    });
}

// The list of authors
const authors = ['Vauxhall', 'Piccadilly', 'Acton', 'Milton', 'Hempsworth'];
const promises = [];

authors.forEach((author) => {
    promises.push(queryPromise(createParams(author)));
});

Promise.all(promises).then(results => {
    // Do your stuff here
}).catch(error => {
    // Handle errors the way you would
});