Mongodb update element inside array

mongodb update element inside array

How to Add Elements into an Array in MongoDB

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I want to update the name of "friends. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Asked 4 years, 3 months ago. Active 6 months ago. Viewed 37k times. Xocoatzin 4, 1 1 gold badge 31 31 silver badges 50 50 bronze badges. Active Oldest Votes. For some reason is not working for me Dherik Do you have a question already with the details for your problem? If not can you create one with a sample document and your desired result? I will try a bit more. Maybe is some driver problem with Robo3T and backward compatibility: stackoverflow. If nothing works, I will open a question. Thank you! I'm using MongoDB 3. Apparently this version not supports this kind of operation. Srivatsa N Srivatsa N 2, 3 3 gold badges 18 18 silver badges 36 36 bronze badges. Below should work fine as its tested First check the current value of the array. Sanjay Bharwani Sanjay Bharwani 1, 17 17 silver badges 19 19 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. A practical guide to writing technical specs. Podcast Cryptocurrency-Based Life Forms. Featured on Meta. Community and Moderator guidelines for escalating issues via new response…. Triage needs to be fixed urgently, and users need to be notified upon…. Dark Mode Beta - help us root out low-contrast and un-converted bits. Technical site integration observational experiment live on Stack Overflow. Linked 0.

Updating Inside a Nested Array with the MongoDB Positional Operator in C#

Posted by: admin December 4, Leave a comment. This cannot be applied in my situation. I really need my object to be nested in arrays. It would be great if you can help me out here. There are a few things wrong with what you are doing here. Firstly your query conditions. Now that would actually work, but really it is only a fluke that it does as there are very good reasons why it should not work for you. What this says is:. Specifically what that means is the element that will be matched and returned in the positional placeholder is the value of the index from the first matching array. So that is the general problem with nesting arrays. From MongoDB 3. The "arrayFilters" as passed to the options for. Any elements that match the condition given will be updated. In this case inner and outer are the identifiers used for each condition as specified with the nested chain. In reality you really need more denormalization. I know this is a very old question, but I just struggled with this problem myself, and found, what I believe to be, a better answer. A way to solve this problem is to use Sub-Documents. This is done by nesting schemas within your schemas. This way the object will look like the one you show, but now each array are filled with sub-documents. This makes it possible to dot your way into the sub-document you want. Instead of using a. January 30, Nodejs Leave a comment. Questions: I am trying to connect to an Oracle database from Node. Is this possible? I have not found a plugin for Node. Are there any recommended wor Now, when a u Add menu. General Scope and Explanation There are a few things wrong with what you are doing here. Try to avoid nesting arrays as you will run into update problems as is shown. Connecting to Oracle database with Node. V8-like Hashtable for C?

MongoDB - update array element in C#

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I'd like to reset the. However it updates only the first matched array element in each document. At this moment it is not possible to use the positional operator to update all items in an array. With the release of MongoDB 3. The "arrayFilters" as passed to the options for. Any elements that match the condition given will be updated. Noting that the "multi" as given in the context of the question was used in the expectation that this would "update multiple elements" but this was not and still is not the case. It's usage here applies to "multiple documents" as has always been the case or now otherwise specified as the mandatory setting of. NOTE Somewhat ironically, since this is specified in the "options" argument for. However this is not true of the mongo shell, since the way the method is implemented there "ironically for backward compatibility" the arrayFilters argument is not recognized and removed by an internal method that parses the options in order to deliver "backward compatibility" with prior MongoDB server versions and a "legacy". So if you want to use the command in the mongo shell or other "shell based" products notably Robo 3T you need a latest version from either the development branch or production release as of 3. Also see Updating a Nested Array with MongoDB for how these new positional operators apply to "nested" array structures, where "arrays are within other arrays". You should ensure your upgrade procedure is complete with details such as index upgrades and then run. Or higher version as is applicable to your installed version. This enabled such features as the new positional update operators and others. You can also check with:. This can also be accomplished with a while loop which checks to see if any documents remain that still have subdocuments that have not been updated. This method preserves the atomicity of your updates which many of the other solutions here do not. The number of times the loop is executed will equal the maximum number of times subdocuments with profile equal to 10 and handled not equal to 0 occur in any of the documents in your collection. So if you have documents in your collection and one of them has three subdocuments that match query and all the other documents have fewer matching subdocuments, the loop will execute three times. This method avoids the danger of clobbering other data that may be updated by another process while this script executes. It also minimizes the amount of data being transferred between client and server. There are in fact methods already in place that "aid" in solutions to this problem, such as Bulk Operations which have been implemented after this original post. It is still not possible to update more than a single matched array element in a single update statement, so even with a "multi" update all you will ever be able to update is just one mathed element in the array for each document in that single statement. The best possible solution at present is to find and loop all matched documents and process Bulk updates which will at least allow many operations to be sent in a single request with a singular response. You can optionally use. Where it's limitation is that if "handled" was in fact a field meant to be present at other document levels then you are likely going to get unexepected results, but is fine where that field appears only in one document position and is an equality match. Future releases post 3. And all releases that support. In all cases where the MongoDB version supports a "cursor" from aggregate output, then this is just a matter of choosing an approach and iterating the results with the same block of code shown to process the Bulk update statements. Bulk Operations and "cursors" from aggregate output are introduced in the same version MongoDB 2. In even earlier versions then it is probably best to just use. If you are aboslutely determined to do "multi" updates or deem that to be ultimately more efficient than processing multiple updates for each matched document, then you can always determine the maximum number of possible array matches and just execute a "multi" update that many times, until basically there are no more documents to update. A valid approach for MongoDB 2. Whatever the case, there are certain things you do not want to do within the update:. This might seem faster to process, but there is no guarantee that the array content has not changed since it was read and the update is performed.

MongoDB - update array element in C#

Sometimes you have a document in MongoDB with a property that is an array of nested objects. One simple way to do it is to load the whole Class document into memory, update the grade in Cand then put the document back into the database. For one thing, its pretty inefficient, especially for a large document. And that the document also included individual paper grades for each student. This is a lot of data to bring across the wire, instantiate C objects for, send back across the wire, then eventually garbage collect the whole document in. NET land. It can add up pretty quick, especially in a high volume environment. A more insidious problem is the race condition involved in updating the whole document. Two threads pull down that document. Then they both write their version of the document back to the database. Will Alice have her 92? Will Bob have his 89? Luckily, MongoDB offers a findAndUpdate operation that can atomically change a subset of the fields in a document. Since the entire document is the unit of atomicity in MongoDB, the two threads can each issue a findAndUpdate at the same time and it will work out OK, provided they are each editing separate students. If both threads are attempting to modify the same student, than just like before, all bets are off. The update description includes that curious string, "Students. That dollar sign is called the Positional Operator. It refers to the first matching element in the array. We also use NumberInt 89 so that Mongo writes an integer instead of a floating point number, which is the default. But what about the Positional Operator? I think the hard-coded -1 index 1 is confusing. Then it might look like:. GetDatabase "school". First. Students[ -1 ]. Grade, 72. In that case you can use c. ElementAt -1 for the same effect. Please enable JavaScript to view the comments powered by Disqus. Id, classToUpdate .

Positional Operator Matching Nested Arrays

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. You need to make use of 2 concepts: mongodb's positional operator and simply using the numeric index for the entry you want to update. As you want to update the 2nd array entry in "items", and array keys are 0 indexed - that's the key 1. This solution works well. Just want to add one point. Here is the structure. I need to find OrderItemId is 'yyy' and update. If the query field in condition is an array, like below "OrderItems. OrderItemId" is array. You can not use "OrderItems. OrderItemId[0]" as operation in the query. Instead, you need to use "OrderItems. OrderItemId" to compare. Otherwise, it can not match one. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Asked 7 years, 11 months ago. Active 11 months ago. Viewed 44k times. Denis Ermolin Denis Ermolin 5, 4 4 gold badges 23 23 silver badges 41 41 bronze badges. Active Oldest Votes. Jan Osch 1, 10 10 silver badges 18 18 bronze badges. AD7six AD7six I don't know the size of the array. Rubin Porwal Rubin Porwal 2, 1 1 gold badge 13 13 silver badges 23 23 bronze badges. Kathy Kathy 3 3 silver badges 7 7 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. A practical guide to writing technical specs. Podcast Cryptocurrency-Based Life Forms. Featured on Meta. Community and Moderator guidelines for escalating issues via new response…. Triage needs to be fixed urgently, and users need to be notified upon….


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