I have a quick question about mongoose schema real quick. Here is the code: https://i.ibb.co/Db8xPMw/5555.png
I tried to create a document without the property "work". It works in the first time, but it didn't start to work on the second time that I do the same thing again.
Do you have any idea?
Basically I create two documents without an "work" property, which causes a duplicate key error. However, I didn't set up unqiue: true though.
Error :
"errmsg" : "E11000 duplicate key error collection: test.user index work_1 dup key: { : null }
From the message it says your collection has an index with name work_1 probably on field work, Since you've created a document without work field then basically you cannot create another document without work field what so ever in the same collection, cause two documents with no work field or even work field with value as null or same cannot exist as it violates unique constraint policies (it says dup key : { : null}) !! Uniques indexes can be created via mongoose schemas or can also be created by manually running queries on database.
Ref : Search for Unique Index and Missing Field in index-unique
So you need to drop the existing index using dropIndex & then if needed recreate it using createIndex. MongoDB would automatically convert a created index to index-multikey (multi-key index - indexes on array fields) if at least one existing document has array value for that indexed field by the time you create index or even if an array value gets inserted for that field in future.
Through code - Drop index : yourSchema.dropIndex({yourFieldName: 1}) && Create index : yourSchema.index({yourFieldName : 1})
NOTE : Just in case if you want to have certain criteria in unique indexes like situation from this question where indexed field can be missing in some documents but it shouldn't be considered as duplicate insertion, then you can take use of partial-indexes (Search for Partial Index with Unique Constraint) which would only index documents where work field exists.
Ex of partial-indexes :-
db.yourCollectionName.createIndex(
{ work: 1 },
{ unique: true, partialFilterExpression: { work: { $exists: true } } }
)
Ref : mongoose-Indexes
Related
When I do a create using sequelize it returns me the response i.e. the newly created entry row in the response,
Sequelize Create Object Code:
let createdObj= await sequelize.ModelName.create(modelObject,{ transaction :t, //more options can be added here, need some value of option that prevents the output inserted })
Below is the query created:
INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) OUTPUT INSERTED.* VALUES (#0,#1,#2,#3,#4)
Now I don't want the output clause to be part of the query, I want a simple insert like:
INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) VALUES (#0,#1,#2,#3,#4)
I don't want the output clause to be part of the query.
How can I achieve this in at the query level as well as at the model level? In some Create operations, I want the output clause and in some create operations, I don't want.
EDIT 1
On Further research I found an option called { returning: false } this does what is required i.e. create an insert query like this INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) VALUES (#0,#1,#2,#3,#4) but now the Sequelize is breaking because it's expecting those values back in return idk why?
C:\Users\MG265X1\project\node_modules\sequelize\lib\dialects\mssql\query.js:389
id = id || results && results[0][this.getInsertIdField()];
^
TypeError: Cannot read property 'id' of undefined
at Query.handleInsertQuery (C:\Users\MG265X1\project\node_modules\sequelize\lib\dialects\mssql\query.js:389:39)
Turns out if an autoIncrementAttribute is present in the model, it will look for the output clause, removing the attribute {autoIncrement: true } from the model hasn't helped as IDENTITY_INSERT cannot be null. How do I move ahead on this??
Edit 2 I could get it working with a combination of { returning: false } and {hasTriggers: true}. Have hasTriggers Attribute as true in your Model, this will allow you to single creates but for bulk Creates pass option returning: false at the time of bulkCreate.
Note: When using bulkCreate with { returning: false } you'll not be able to get the autogenerated Id, It's a trade-off that we had to live with as we want
bulkCreate to work with triggers, we ended up fetching the Id later from DB
Seems I raised this issue but was closed as it wasn't good SSCCE
so I have a mongoose schema in my node application with two fields: tag and task, and I want to be able to save entries where the combination of both properties doesnt exist yet.
For example: my DB already has the following entries:
{tag:tag1, task:task1}
{tag:tag1, task:task2}
{tag:tag2, task:task1}
I want to be able to create {tag:tag2, task:task2}, but not {tag:tag1, task:task1} again, so I guess I cant use primary or unique in any of those fields, since they can repeat, except when their combination already exists
so which query should I use to save? Or should I find if it already exists first?
Use Unique Compound Indexing
db.users.createIndex( { "tag": 1, "task": 1 }, { unique: true } )
For more info visit the Link
This code won't work, I got error of E11000 duplicate key error index error.
Student.update({_id: id, 'data.date':date}, {'$set': {'data.score': 50}}, {upsert: true},
function(err,result) {
res.json(1);
});
I have no clue how to solve it when I can do
Student.findOne({_id: id}, function(err,result){
res.json(result)
})
Any clue what's going on?
I see two possible problems:
You may have set some of the fields as unique and Mongo created an index for that field. For example if data.score would be unique then you couldn't have two documents with the same value and maybe other document already has a value of 50.
The solution would be to search for indexes and remove the ones that you don't want.
Maybe your search for {_id: id, 'data.date': date} doesn't return a result but not because you don't have a document with that id, but because it doesn't have that 'data.date' field that you search for. Then the upsert tries to insert a new document (because the search didn't find anything that has both '_id' equal to id and 'data.date' equal to date) but it fails to do so (because you already have a document with '_id' equal to id).
The solution would be to search only by _id if you're using upsert.
I am writing a REST api which I want to make idempotent. I am kind of struggling right now with nested arrays and idempotency. I want to update an item in product_notes array in one atomic operation. Is that possible in MongoDB? Or do I have to store arrays as objects instead (see my example at the end of this post)? Is it for example possible to mimic the upsert behaviour but for arrays?
{
username: "test01",
product_notes: [
{ product_id: ObjectID("123"), note: "My comment!" },
{ product_id: ObjectID("124"), note: "My other comment" } ]
}
If I want to update the note for an existing product_node I just use the update command and $set but what if the product_id isn't in the array yet. Then I would like to do an upsert but that (as far as I know) isn't part of the embedded document/array operators.
One way to solve this, and make it idempotent, would be to just add a new collection product_notes to relate between product_id and username.
This feels like violating the purpose of document-based databases.
Another solution:
{
username: "test01",
product_notes: {
"123": { product_id: ObjectID("123"), note: "My comment!" },
"124": { product_id: ObjectID("124"), note: "My other comment" } }
}
Anyone a bit more experienced than me who have anything to share regarding this?
My understanding of your requirement is that you would like to store unique product ids (array) for an user.
You could create an composite unique index on "username" and "username.product_id". So that when the same product id is inserted in the array, you would an exception which you could catch and handle in the code as you wanted the service to be Idempotent.
In terms of adding the new element to an array (i.e. product_notes), I have used Spring data in which you need to get the document by primary key (i.e. top level attribute - example "_id") and then add a new element to an array and update the document.
In terms of updating an attribute in existing array element:-
Again, get the document by primary key (i.e. top level attribute -
example "_id")
Find the correct product id occurrence by iterating the array data
Replace the "[]" with array occurrence
product_notes.[].note
I'm using YDN-DB (an abstraction on top of IndexedDB) as a local database. I have an object store called 'conversations', and in that store, there's an index called 'participants' where there is a string containing id's for different users in the conversation. For example:
Example Conversation #1:
id: 1234343434353456,
participants: '171e66ca-207f-4ba9-8197-d1dac32499db,82be80e2-2831-4f7d-a8d7-9223a2d4d511'
Example Conversation #2:
id: 4321343434356543,
participants: 'd7fa26b3-4ecc-4f84-9271-e15843fcc83f,171e66ca-207f-4ba9-8197-d1dac32499db'
To try to perform a partial match on an index, I tried using ydn-db-fulltext as a solution. The full text catalog looks like this:
{
name: 'participants',
lang: 'en',
sources: [
{
storeName: 'conversations',
keyPath: 'participants',
weight: 1
}
]
}
I see that the catalog is generated, but there seems to be a problem doing exact matches. For example, if I query using only part of the key in the participants index, I get back a primary key from the catalog:
db.search('participants', 'd7fa26b3').done(function(results) {
if(results.length == 0) console.debug('No results found...');
console.debug(results); // there is 1 object here!
var primaryKey = results[0].primaryKey; // primaryKey exists!
});
However, when using any value past the '-', the search request returns 0 results:
db.search('participants', 'd7fa26b3-4ecc-4f84-9271-e15843fcc83f').done(function(results) {
if(results.length == 0) console.debug('No results found...');
console.debug(results); // there are 0 objects in the array
var primaryKey = results[0].primaryKey; // primaryKey throws undefined since there are 0 results!
});
This makes sense, when reading the documentation, in that '-' and '*' are reserved characters that remove a phrase and match a prefix respectively:
Query format is free text, in which implicit and/or/near logic operator apply for each token. Use double quote for exact match, - to subtract from the result and * for prefix search.
I tried putting double quotes inside the single quotes, using only double quotes, and also escaping all of the '-' characters with a backslash, but none of these seem to work.
So the question is how does one perform a match in an index where the string contains '-' characters?
Have you try db.search('participants', '"d7fa26b3"').
BTW, you are using full text search that is not suppose to do. You have to tokenize your string and index them manually.
If you store the participants field of your object as an array, then you can use the multi-entry flag to the createIndex method called on the participants field, and probably do what you want.
The number of items in the participants property of the object is mutable. When you update an object in the store and it has a different number of items in the partic property, then the index is automatically updated as a result (just like any other index). If you add an item to the prop, then restore (put/override/cursor.update) the object in the store, the index updates.
It helps to review the basics of how a multi-entry index works. You can do this with vanilla js, without a framework, and certainly without full-text searching.