我一直在关注显示的 javascript 存储过程示例 here
下面的代码尝试编写更新存储过程示例的修改版本。这就是我正在尝试做的事情:
- 我不想对单个文档进行操作,而是想执行 更新所提供的查询返回的文档集。
- (可选)返回响应正文中更新文档的计数。
代码如下:
function updateSproc(query, update) {
var collection = getContext().getCollection();
var collectionLink = collection.getSelfLink();
var response = getContext().getResponse();
var responseBody = {
updated: 0,
continuation: false
};
// Validate input.
if (!query) throw new Error("The query is undefined or null.");
if (!update) throw new Error("The update is undefined or null.");
tryQueryAndUpdate();
// Recursively queries for a document by id w/ support for continuation tokens.
// Calls tryUpdate(document) as soon as the query returns a document.
function tryQueryAndUpdate(continuation) {
var requestOptions = {continuation: continuation};
var isAccepted = collection.queryDocuments(collectionLink, query, requestOptions, function (err, documents, responseOptions) {
if (err) throw err;
if (documents.length > 0) {
tryUpdate(documents);
}
else if (responseOptions.continuation) {
// Else if the query came back empty, but with a continuation token; repeat the query w/ the token.
tryQueryAndUpdate(responseOptions.continuation);
}
else {
// Else if there are no more documents and no continuation token - we are finished updating documents.
responseBody.continuation = false;
response.setBody(responseBody);
}
});
// If we hit execution bounds - return continuation:true
if (!isAccepted) {
response.setBody(responseBody);
}
}
// Updates the supplied document according to the update object passed in to the sproc.
function tryUpdate(documents) {
if (documents.length > 0) {
var requestOptions = {etag: documents[0]._etag};
// Rename!
rename(documents[0], update);
// Update the document.
var isAccepted = collection.replaceDocument(
documents[0]._self,
documents[0],
requestOptions,
function (err, updatedDocument, responseOptions) {
if (err) throw err;
responseBody.updated++;
documents.shift();
// Try updating the next document in the array.
tryUpdate(documents);
}
);
if (!isAccepted) {
response.setBody(responseBody);
}
}
else {
tryQueryAndUpdate();
}
}
// The $rename operator renames a field.
function rename(document, update) {
var fields, i, existingFieldName, newFieldName;
if (update.$rename) {
fields = Object.keys(update.$rename);
for (i = 0; i < fields.length; i++) {
existingFieldName = fields[i];
newFieldName = update.$rename[fields[i]];
if (existingFieldName == newFieldName) {
throw new Error("Bad $rename parameter: The new field name must differ from the existing field name.")
} else if (document[existingFieldName]) {
// If the field exists, set/overwrite the new field name and unset the existing field name.
document[newFieldName] = document[existingFieldName];
delete document[existingFieldName];
} else {
// Otherwise this is a noop.
}
}
}
}
}
<小时/>
我通过 Azure Web 门户运行此存储过程,这些是我的输入参数:
- 从根目录中选择 *
- {$重命名:{A:“B”}}
我的文档看起来像这样:
{ id: someId, A: "ChangeThisField" }
字段重命名后,我希望它们看起来像这样:
{ id: someId, B: "ChangeThisField" }
我正在尝试使用此代码调试两个问题:
- 更新后的计数非常不准确。我怀疑我对延续 token 做了一些非常愚蠢的事情 - 部分问题是我不太确定如何处理它。
- 重命名本身并未发生。
console.log()
调试显示我永远不会进入重命名函数中的if (update.$rename)
block 。
最佳答案
我修改了您的存储过程代码,如下所示,它对我有用。我没有使用对象或数组作为我的 $rename
参数,我使用了 oldKey
和 newKey
相反。如果您确实关心参数的构造,则可以将 rename
方法更改回来,这不会影响其他逻辑。请引用我的代码:
function updateSproc(query, oldKey, newKey) {
var collection = getContext().getCollection();
var collectionLink = collection.getSelfLink();
var response = getContext().getResponse();
var responseBody = {
updated: 0,
continuation: ""
};
// Validate input.
if (!query) throw new Error("The query is undefined or null.");
if (!oldKey) throw new Error("The oldKey is undefined or null.");
if (!newKey) throw new Error("The newKey is undefined or null.");
tryQueryAndUpdate();
function tryQueryAndUpdate(continuation) {
var requestOptions = {
continuation: continuation,
pageSize: 1
};
var isAccepted = collection.queryDocuments(collectionLink, query, requestOptions, function (err, documents, responseOptions) {
if (err) throw err;
if (documents.length > 0) {
tryUpdate(documents);
if(responseOptions.continuation){
tryQueryAndUpdate(responseOptions.continuation);
}else{
response.setBody(responseBody);
}
}
});
if (!isAccepted) {
response.setBody(responseBody);
}
}
function tryUpdate(documents) {
if (documents.length > 0) {
var requestOptions = {etag: documents[0]._etag};
// Rename!
rename(documents[0]);
// Update the document.
var isAccepted = collection.replaceDocument(
documents[0]._self,
documents[0],
requestOptions,
function (err, updatedDocument, responseOptions) {
if (err) throw err;
responseBody.updated++;
documents.shift();
// Try updating the next document in the array.
tryUpdate(documents);
}
);
if (!isAccepted) {
response.setBody(responseBody);
}
}
}
// The $rename operator renames a field.
function rename(document) {
if (oldKey&&newKey) {
if (oldKey == newKey) {
throw new Error("Bad $rename parameter: The new field name must differ from the existing field name.")
} else if (document[oldKey]) {
document[newKey] = document[oldKey];
delete document[oldKey];
}
}
}
}
我只有3个测试文档,所以我将pagesize
设置为1
来测试延续的用法。
测试文档:
输出:
希望对您有帮助。如有任何疑问,请告诉我。
关于azure - 如何在 CosmosDB Javascript 存储过程中执行批量字段重命名,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51769124/