Cannot create unique index when collection contains documents 

Cannot create unique index when collection contains documents. Aug 19, 2022 · The db. See also Sharded Collection and Unique Indexes. The command either updates a matching document and returns the updated document or, if no matching document exists, inserts a document and returns the newly inserted document in the value field. Put another way: a sparse compound index will only skip a document if all of the index fields are missing from the document. shardedCollection. createIndex({someField: 1}, {unique: true}) Optional. For MongoDB containers, use mongoimport. With an indexed defined with {"name":1, "age":1}, {unique:true} then the last document insertion fails as it should. The collection is created as part of the operation. 2: MongoDB 4. Although this is disappointing, apparently it is not possible to create an index within a transaction on an existing, non-empty collection. Dec 11, 2019 · The unique index cannot be modified. enforces uniqueness for the indexed fields. It allows creation of an array of a particular runtime type. Dec 2, 2022 · a non-existing collection. Nov 9, 2023 · I have empty collection which has only "_id" unique index created by default, I can not create any new unique index in any of the collection. MongoDB will not create an index on a collection if the index entry for an existing document exceeds the index key limit (1024 bytes). Oct 20, 2015 · Cannot reproduce. 000Z, no documents are deleted from the collection by the TTL "time to live" feature. A unique index stores a null value for a document missing the indexed field; that is a missing index field is treated as another instance of a null index key value. createCollection() method, and indexes, e. Reload to refresh your session. As suggested, it is supected that your collection already contains duplicate data and a procedure for removal is given. For an ascending index on a field, specify a value of 1; for descending index, specify a value of -1. You will need to remove any existing documents in the collection that are duplicates before building the index. The unique columns are duplicates, but other columns have different data) then you may have to clean up the data. createIndex( { "shardKey": 1, "uniqueField": 1 }, { unique: true } ); This is an example of creating a unique index on a sharded collection that includes the shard key and another field. You cannot use these commands with multi-document transactions. }) Here, insertOne () function is used to store single data in the specified collection. anotherCollection. I think the best solution would be if the mongorestore would automatically omit the unique: true option if it's set for an _id: 1 index. 2) From the mongo shell, execute the command: db. For an ascending index on a field, specify a value of 1; for the descending index, specify a value of -1. Partial indexes determine the index entries based on the specified filter. The default value is false. createIndexes() and db. 3 adds the bucketMaxSpanSeconds and bucketRoundingSeconds parameters. Optional. May 26, 2020 · It states - MongoDB cannot create a unique index on the specified index field(s) if the collection already contains data that would violate the unique constraint for the index. exe to move data. You cannot specify a descending index key when creating a wildcard index. Typically, best practice is to create a separate table that contains the duplicates, and then use your best judgment to delete one of the rows. 0. To circumvent this issue, you can manually create the corresponding collections and unique indexes instead of allowing the migration tool to try. To add a unique index you can use: db. Use the appropriate data migration tool to move the data from the existing container to the new container. Wildcard indexes support workloads where users query against custom fields or a large variety of fields in a collection: To create a wildcard index on all fields and subfields in a document, specify { "$**" : 1 } as the index key. Mar 12, 2021 · The collection contains a few fields and I created an index with the UNIQUE flag by 3 fields, for example: name + surname + age. For example, you use db. { name: 1 }, db. Configuration. There are unique keys but they can only be created upon container creation (see Unique key constraints in Azure Cosmos DB: "You can define unique keys only when you create an Azure Cosmos DB container. " Documents have the following restrictions on field names: The field name _id is reserved for use as a primary key; its value must be unique in the collection, is immutable, and may be of any type other than an array. g. For example, consider a collection that contains the following document: db. createCollection () to create a: . List the columns to be included in the composite index, in sort-priority order, inside the parentheses after table_or_view_name. firestore() If an appropriate index exists for a query, MongoDB can use the index to limit the number of documents it must inspect. If just a test, then drop the collection and start again. getIndexes()), remove the index on "Key. For example, I can index indexContents alone fine. Feb 2, 2024 · With MongoDB 5. For more information, see Missing Document Field in a Unique Single-Field Index. createIndex () takes the following parameters: A document that contains the field and value pairs where the field is the index key and the value describes the type of index for that field. const firebaseApp = construct your firebase app. createIndex() method with the sparse option set to true. You may not specify a unique constraint on a hashed index . And in the curly braces {} we store our data or in other words, it is a Nov 9, 2023 · Database version : 3. You cannot create a unique constraint if the existing data does not provide uniqueness. In the Add Index dialog, type the name of your index in the Index name box. It says there are duplicate values but: Oct 12, 2022 · You can fetch a single document at a time and delete it through a loop. Sep 13, 2020 · You signed in with another tab or window. If I manually try to delete the key, it is taking hours. Because MongoDB creates a collection implicitly when the collection is first referenced in a command, this method is used primarily for creating new collections that use specific options. sample. By default, the db. If you leave the Index name box empty, Studio 3T creates a default index name for you, based on the names of the fields that you select and the index type. createIndex ( { groupNumber: 1, lastname: 1, firstname: 1 }, { unique: true } ) The created index enforces uniqueness for the combination of groupNumber, lastname, and firstname 1) Remove all documents from the users collection. Due to the duplication of key patterns, adding a unique index to already indexed fields is possible. The option is unavailable for hashed indexes. The created index can support queries on Optional. You would need to ensure the data is unique before creating the constraint. If you cannot stop all writes to the collection, do not use the following procedure to create unique indexes. Here are some mongosh commands to do this: db. MongoDB 6. 2. 6 Point in time restore is enabled. The unique index allows the insertion of a document without the field x if the collection does not already contain a document missing the field x: db. Before inserting into Sample, always first try to insert into Sample_proxy. "disableKeyBasedMetadataWriteAccess": false, I have empty collection which has only "_id"; unique index Aug 13, 2021 · Creating collection: After creating database now we create a collection to store documents. The script can't know which of those "duplicate" rows is actually needed. The collection is created using the following syntax: db. You switched accounts on another tab or window. createIndex ( {email: 1}, {unique: true}) Regarding step 1, note that from Mongo's docs: MongoDB cannot create a unique index on the specified index field (s) if the collection already contains data that would violate the unique constraint Changed in version 4. _id: 1 } with shard key Optional. MongoTemplate and ReactiveMongoTemplate provide methods for managing indexes and collections. 3, you must either drop all collections with these parameters, or modify them to use the corresponding granularity, if possible. 0, you may have basic and unique indexes with the same key pattern. Note: If actual insert fails, remember to delete the document from . Things fail if when I tried to index {LongitudeLatitude:"2d",indexContents:1,Prominent:1} For example, to create a unique index on groupNumber, lastname , and firstname fields of the members collection, use the following operation in the mongo shell: db. Example: Make a basic index with the key pattern { score: 2 } and insert three documents. Unlike relational databases, MongoDB does not offer the option to create constraints. 2 wildcard indexes support workloads where users query against custom fields or a large variety of fields in a collection: To create a wildcard index on all fields and subfields in a document, specify { "$**" : 1 } as the index key. Currently, you can only create unique indexes when the collection contains no documents. Creates a unique index so that the collection will not accept insertion or update of documents where the index key value matches an existing value in the index. createIndex (. If a time series collection contains documents with timeField timestamps before 1970-01-01T00:00:00. Nov 6, 2023 · Hi , The above feature is in private preview, you can raise a support request to get it enabled. createIndex ( { groupNumber: 1, lastname: 1, firstname: 1 }, { unique: true } ) The created index enforces uniqueness for the combination of groupNumber, lastname, and firstname Changed in version 4. createIndex() methods Sep 14, 2011 · 3. If not, do the actual insert into Sample. Although you can have a unique compound index where the shard key is a prefix, if using unique parameter, the collection must have a unique index that is on the shard key. Unique indexes will not accept insertion or update of documents where the index key value matches an existing value in the index. The reason is because you are on a sharded cluster and you are identifying the document you wish to update with an index that is neither unique nor is it the shard key however you have specified that you only want to update 1 document. If insert into Sample_proxy fails => unique index violation. Jun 28, 2019 · The only workaround is to have the *. getSiblingDB('database'). There is no such thing as a "unique index" for "Cosmos DB for SQL". Resolution: if index not present create it, if present and unique then recreate as not unique. addresses. Sep 5, 2018 · Sample is sharded while Sample_proxy is not. Index and Collection Management. createIndex ( { groupNumber: 1, lastname: 1, firstname: 1 }, { unique: true } ) The created index enforces uniqueness for the combination of groupNumber, lastname, and Jan 18, 2011 · I'm trying to create a unique index on code field: $ CREATE UNIQUE INDEX "one_code_per_person" on "core_person"("code") WHERE "code" IS NOT NULL; ERROR: could not create unique index "one_code_per_person" DETAIL: Table contains duplicated values. I can index {LongitudeLatitude:"2d",Prominent:1} {indexContents:1} fine. My next attempt was to create a new collection and create the unique indexes first, before adding any documents to the collection. A document that contains the field and value pairs where the field is the index key and the value describes the type of index for that field. products_catalog. If a given field is a nested document or array, the wildcard index recurses into the document/array and indexes all scalar fields in the document/array. For example, to create a unique index on groupNumber, lastname , and firstname fields of the members collection, use the following operation in mongosh: db. 0 } with shard key pattern For a compound multikey index, each indexed document can have at most one indexed field whose value is an array. "disableKeyBasedMetadataWriteAccess": false, I have empty collection which has only "_id"; unique index The method can modify specific fields of an existing document or documents or replace an existing document entirely, depending on the update parameter. Mar 30, 2021 · I have an mongo instance (about 120GB RAM, 250GB SSD) running 4. Field names cannot contain the null character. collection . leafygreen-ui-ldnju>p {margin-bottom:8px;} Capped collection. For SQL containers, use the Data Migration tool to move data. createIndex( { "$**" : 1 } ) With this wildcard index, MongoDB indexes all scalar fields for each document in the collection. 66 Nov 13, 2022 · For example, SQL Server used to (and may still) disallow multiple nulls in a unique index by default – you have to create a filtered unique index (analogous to a partial index in MongoDB). Specify true to create a unique index. So an unique index can be created on Sample_proxy. Collation Apr 9, 2019 · You use a custom list as a checklist and want to make sure all entries are unique (unique value on the Title or custom text column) You use a document library to organize various policies (files) that are part of your company handbook and want to make sure your chapter and section numbers are unique and cannot be assigned to more than 1 For MongoDB accounts, you create unique index using extension commands. Explicit creation of collections , e. May 5, 2023 · In Object Explorer, expand the database that contains the table on which you want to create a unique index. Suppose x is a collection known to contain only strings. createCollection() typically holds this lock for a short time. When I insert documents with the following Java format repository. The index stores the value of a specific field or set of fields, ordered by the value of the field. So no you can't do this if you have multiple NULL values for the key. You can however create a hashed index or text index instead: or. Apr 1, 2012 · Create index on a sharded collection with 1 chunk on shard A and no chunks on shard B: "cannot create unique index over { z: 1. You signed out in another tab or window. Then you can create normal index. However, the unique index errors on the insertion of a document without the field x if the collection already contains a document missing the field x: db . const updateUser = async (id, username) => {. The filter can include fields other than the index keys and can specify conditions other than just an existence check. Indexes are special data structures [ 1] that store a small portion of the collection's data set in an easy to traverse form. Use the expireAfterSeconds option to specify a TTL value in seconds. I have a large collection of about 300M documents and I want to add an unique index on a collection. createIndex ( { groupNumber: 1, lastname: 1, firstname: 1 }, { unique: true } ) The created index enforces uniqueness for the combination of groupNumber, lastname, and firstname Posted by u/saga04 - No votes and no comments Nov 9, 2023 · Database version : 3. Therefore, our only option is to create unique indexes. 000Z or after 2038-01-19T03:14:07. 61: ShardKeyNotFound: The document in your request didn't contain the collection's shard key (Azure Cosmos DB partition key). Nov 9, 2023 · Database version : 3. From the mongo shell or mongosh: db. So if your collection if u have few documents already having the same email value then if u are trying to create index on email field, it might not work. Specify an index field that is either a date type or an array that contains date type values. If the collection is not empty, you must create the index first before using shardCollection. Specify two or more column names to create a composite index on the combined values in the specified columns. This is normal database practice, it's not HANA specific. There are no other restrictions. members. Notice other ensure index is fine. contacts. – Jan 17, 2024 · Cannot create unique index when collection contains documents. Include the option multi: true to update all documents that match the query criteria. All subsequent operations on the collection must wait until db. exe or mongorestore. I have, using the emulator, tried this on databases with provisioned throughput on and off with the same result . Aug 29, 2012 · update: I already repairDatabase but i got the same resutl, can't create indexContent. update() method updates a single document. You can access these operations by calling the indexOps method and passing in either the collection name Aug 6, 2020 · Adding an index. Jun 7, 2023 · 3. insert( { y: 1 } ) However, the unique index errors on the insertion of a document without the field x if the collection already contains a document missing the field x: db. For building unique indexes. If so, remove those documents and try adding the key again. createIndex( email, { unique: true } ) A unique index ensures that the indexed fields do not store duplicate values; i. json files edited to with the unique: true option removed (in case of a large number of the affected collections that would be cumbersome). I think the most straightforward way to ignore null values for the purposes of a unique index would be to avoid serialising null property values. For example, to create a TTL index on the lastModifiedDate field of the eventlog collection, with a TTL value of 3600 seconds, use the Oct 6, 2023 · When creating unique key, the data already exists on db should not violate unique key constraint. This will help you slowly delete data without impacting your production application. IdentifierValue" (assuming it is not unique), and create it as unique. Find the overlength values and shorten them if you can. Has anyone been able to do this? For example, to create a unique index on groupNumber, lastname , and firstname fields of the members collection, use the following operation in mongosh: db. Check if the data for the column have same values to violate unique key constraint. collection_name. And seems dropDupes option To create a sparse index, use the db. insertOne({. In the connection tree, right-click a collection, and then select Add Index. MongoDB doesn't support unique indexes that span several collections, so a good approach here would be to use a single collection with a unique index on employee_username, with documents having this sort of structure: users. For details see collMod. That is: You cannot create a compound multikey index if more than one to-be-indexed field of a document is an array. Right-click the table on which you want to create a unique index and select Design. createCollection() obtains an exclusive lock on the specified collection or view for the duration of the operation. In the Indexes/Keys dialog box, click Add. CommandResult cr = null; IndexOptionsDocument NotUnique = new For example, to create a unique index on groupNumber, lastname , and firstname fields of the members collection, use the following operation in mongosh: db. Ensure the collection's shard key is being used in the request. "disableKeyBasedMetadataWriteAccess": false, I have empty collection which has only "_id"; unique index Jan 8, 2024 · Unique fields are an essential part of the DB design. Feb 2, 2024 · Without satisfying this requirement, you cannot create a unique index on a sharded collection. 10. saveAll(list) , and my collection already contains part of these documents - Mongo throws an Exception in my face like: Database version : 3. users. To change the unique index, remove the collection and re-create a new one. metadata. The index creation is quite slow, takes about 2 hours despite using most of the RAM and it is erroring out at 99% saying there is a dupe key. When trying to create the missing index you get the following error: cannot CREATE UNIQUE INDEX; duplicate key found: [5] Several documents with the same ID exist in the index; <SCHEMA_NAME>:&a Nov 3, 2014 · Sparse compound indexes will create an index entry for a document if any of the fields exist, setting the value to null in the index for any fields that do not exist in the document. Nov 16, 2021 · You can create an index before the collection is created. insert ( { z : 1 } ) The operation fails to insert the document because of the violation of the unique constraint on the value of the field x : Optional. Default setting for unique is 'not unique'. createIndex ( { groupNumber: 1, lastname: 1, firstname: 1 }, { unique: true } ) The created index enforces uniqueness for the combination of groupNumber, lastname, and firstname Transaction ST04 reports a missing primary index in a table. Expand the Tables folder. To create unique indexes using the following procedure, you must stop all writes to the collection during the index build. scores. Starting in MongoDB 4. These methods are collected into a helper interface called IndexOperations respectively ReactiveIndexOperations . If the _id contains subfields, the subfield names cannot begin with a ($) symbol. ( multi: false) Consider that when you make a query that does not include the shard key, mongodb has to Mar 11, 2016 · I'm trying to index the embedded documents where the main collection is using the hash sharding. – If they are not true duplicates (i. Nov 29, 2017 · To update our User 's username we use a batch write to update the User document, delete the previous Index document and create a new Index document all at the same time. Use toArray() to create an array whose runtime type is Object[] , or use toArray(T[]) to reuse an existing array. When you create a wildcard index, you specify $** to represent all fields or all values, allowing you to index any of the following with a single command: All values of a field. createIndex ( { "xmpp_id": 1 }, { sparse: true } ) The index does not index documents that do not include Return New Document. Or create a new database with required keys, and then import the data to db. createIndexes( [ { "$**" : 1 } ] ) With this wildcard index, MongoDB indexes all scalar fields for each document in the collection. a new empty collection created earlier in the same transaction. The following findAndModify command includes both upsert: true option and the new:true option. "disableKeyBasedMetadataWriteAccess": false, I have empty collection which has only "_id"; unique index This method acts as a bridge between array-based and collection-based APIs. Otherwise, you may end up with inconsistent data across the replica set members. Sep 22, 2010 · In the above table, you couldn't create a unique index on (col1,col2), exactly because the data in it would be non-unique (multiple rows with (bar,2)). e. createCollection() releases the lock. createIndex( { score : 1 }, { name: "basic_index" } ) db Changed in version 4. The create command has the following syntax: Note. Dec 8, 2021 · To set a unique key for an existing container, create a new container with the unique key constraint. To downgrade below 6. The following operation creates a wildcard index on all scalar fields (excluding the _id field): use inventory. createCollection("anotherCollection") db. createIndex( { email: 1 }, { unique: true } ) MongoDB cannot create a unique index on the specified index field(s) if the collection already contains data that would violate the unique constraint for the index. All fields in a document. They guarantee consistency and performance at the same time, preventing duplicate values where there shouldn’t be. For example, a partial index can implement the same behavior as a sparse index: db. For example, I don't have a collection called as users, and I am creating an unique index on the email field. For an already-sharded collection, you cannot create unique indexes on other fields. For example, the following operation in mongosh creates a sparse index on the xmpp_id field of the addresses collection: db. collection Mar 23, 2016 · 22. There are three options available to it: create a UNIQUE index with duplicate rows (invalid, as it's not unique any more) Syntax. For example, if you write to an existing collection in one shard and implicitly create a collection in a different shard, MongoDB cannot perform both operations in the same transaction. Aug 15, 2019 · 1. createIndex () method is used to builds an index on a collection. 2, you can use wildcard indexes to support queries against multiple, arbitrary, or unknown fields. _id: ObjectId("47cc67093475061e3d95369d"), location: "newyork", employee_username: "susan". By default, MongoDB creates a unique index on the _id field during the creation of a collection. cannot create unique index over {EDs. Popular MongoDB migration tools try to create the unique indexes after importing the data. The Add index dialog. If a given field is a nested document or array, the wildcard index recurses into the Nov 30, 2022 · Check what the existing index is (db. db. . collection. On the Table Designer menu, select Indexes/Keys. Whenever some piece of code was forcing this index to be unique (as I think it should), aforementioned exception occurred on deleting from Mongo. Changed in version 4. To create a TTL index, use createIndex() . const database = firebaseApp. Up to 32 columns can be combined into a single composite index key. vn zp jq vm ca gf ax de pq ms