distinct

R2026b

Retrieve distinct values from MongoDB collection

Since R2026b

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    Syntax

    values = distinct(mongodbconn,collectname,field)
    values = distinct(mongodbconn,collectname,field,Query=mongoquery)

    Description

    values = distinct(mongodbconn,collectname,field) returns the unique values of the specified field from all documents in the MongoDB® collection.

    values = distinct(mongodbconn,collectname,field,Query=mongoquery) specifies additional options using one or more name-value arguments. For example, specify a query string using mongoquery to filter documents before retrieving distinct values. Use this syntax to retrieve distinct values from a subset of documents that match specific criteria.

    example

    Examples

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    Open Live Script

    Retrieve distinct values from all documents in a MongoDB® collection and from a subset that matches a query.

    Use the mongoc function to create the database connection.

    port = 27017;
dbname = "mongotest";

mongodbconn = mongoc(getSecret("mongoc_server"),port,dbname, ... 
    UserName = getSecret("mongoc_username"), ... 
    Password = getSecret("mongoc_password"));

    Create a set of documents and insert them into a collection.

    collection = "employeeCollection";

docs(1) = struct("name", "Alice", "department", "Engineering", "status", "active", "salary", 90000);
docs(2) = struct("name", "Bob",   "department", "Engineering", "status", "inactive", "salary", 85000);
docs(3) = struct("name", "Carol", "department", "HR",          "status", "active",   "salary", 60000);
docs(4) = struct("name", "David", "department", "HR",          "status", "active",   "salary", 62000);
docs(5) = struct("name", "Eve",   "department", "Sales",       "status", "active",   "salary", 70000);
docs(6) = struct("name", "Frank", "department", "Sales",       "status", "inactive", "salary", 68000);

createCollection(mongodbconn,collection);
insert(mongodbconn,collection,docs);

    Retrieve distinct values from all documents in the collection.

    field = "name";
values = distinct(mongodbconn,collection,field)
    values = 6×1 cell array
    {'Alice'}
    {'Bob'  }
    {'Carol'}
    {'David'}
    {'Eve'  }
    {'Frank'}

    Filter documents using a query and retrieve distinct values.

    mongoquery = "{""department"":""Sales""}";
values = distinct(mongodbconn,collection,field,Query=mongoquery)
    values = 2×1 cell array
    {'Eve'  }
    {'Frank'}

    Close the database connection.

    dropCollection(mongodbconn,collection);
close(mongodbconn);

    Input Arguments

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    MongoDB C++ interface connection, specified as a connection object.

    MongoDB collection name, specified as a string scalar or character vector. The function retrieves distinct values from documents in the specified collection.

    Field name in the MongoDB collection, specified as a string scalar or character vector. The function retrieves distinct values from the specified field in documents in the collection.

    MongoDB query, specified as a string scalar or character vector. The query filters documents in the collection before retrieving distinct values from the specified field. Specify the query using JSON-style syntax.

    Example: "{""department_id"":80}"

    Output Arguments

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    Distinct values from the specified field in the MongoDB collection, returned as a cell array. Values are returned from all documents in the collection, or from documents that match the specified query, if provided.

    Version History

    Introduced in R2026b

    See Also

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