如何使用 Azure DocumentDB 执行 UPSERT？

Azure DocumentDB 不支持 UPSERT。是否有合理的解决方法来实现相同的功能？

使用存储过程检查文档是否存在以确定是否应该执行插入或更新是否是一种有效的策略？

如果我需要批量执行数千个这样的操作怎么办？

在这里为该功能投票：

http://feedback.azure.com/forums/263030-documentdb/suggestions/7075256-provide-for-upsert http://feedback.azure.com/forums/263030-documentdb/suggestions/7075256-provide-for-upsert

Update- 这是我尝试批量更新插入存储过程。

function bulkImport(docs) { 
    var collection = getContext().getCollection(); 
    var collectionLink = collection.getSelfLink(); 
    var count = 0; 

    if (!docs) throw new Error('Docs parameter is null'); 

    var docsLength = docs.length; 
    if (docsLength == 0) { 
        getContext().getResponse().setBody(0); 
    } 

    tryUpsert(docs[count], callback); 

    function tryUpsert(doc, callback) {

        var query = { query: ""select * from root r where r.id = @id"", parameters: [ {name: ""@id"", value: doc.id}]};

        var isAccepted = collection.queryDocuments(collectionLink, query, function(err, resources, options) {
            if (err) throw err;                           

            if(resources.length > 0) {
                // Perform a replace       
                var isAccepted = collection.replaceDocument(resources[0]._self, doc, callback);     
                if (!isAccepted) getContext().getResponse().setBody(count);                          
            }
            else {
                // Perform a create
                var isAccepted = collection.createDocument(collectionLink, doc, callback);   
                if (!isAccepted) getContext().getResponse().setBody(count);                             
            }
        });  

        if (!isAccepted) getContext().getResponse().setBody(count); 
    }

    function callback(err, doc, options) { 
        if (err) throw err; 

        // One more document has been inserted, increment the count. 
        count++; 

        if (count >= docsLength) { 
            // If we have created all documents, we are done. Just set the response. 
            getContext().getResponse().setBody(count); 
        } else { 
            // Create next document. 
            tryUpsert(docs[count], callback); 
        } 
    } 
} 

更新（2015-10-06）： 原子更新插入 https://azure.microsoft.com/en-us/blog/documentdb-adds-upsert/Azure DocumentDB 现在支持。

是的，存储过程非常适合更新插入。

DocumentDB 的 Github 上甚至还提供了代码示例：

• 更新插入（针对插入进行了优化）：https://github.com/aliuy/azure-node-samples/blob/master/documentdb-server-side-js/stored-procedures/upsert.js https://github.com/aliuy/azure-node-samples/blob/master/documentdb-server-side-js/stored-procedures/upsert.js

• 更新插入（针对替换进行了优化）：https://github.com/aliuy/azure-node-samples/blob/master/documentdb-server-side-js/stored-procedures/upsertOptimizedForReplace.js https://github.com/aliuy/azure-node-samples/blob/master/documentdb-server-side-js/stored-procedures/upsertOptimizedForReplace.js

• 批量导入/更新插入：https://github.com/Azure/azure-documentdb-hadoop/blob/master/src/BulkImportScript.js https://github.com/Azure/azure-documentdb-hadoop/blob/master/src/BulkImportScript.js