Create a Collection with Collation

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Collation allows you to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

Limitations

The following restrictions apply when the parameter numericOrdering is set to true:

Only contiguous non-negative integer substrings of digits are considered in the comparisons. numericOrdering does not support:
- +
- -
- exponents
Only Unicode code points in the Number or Decimal Digit (Nd) category are treated as digits.
If the number length exceeds 254 characters, the excess characters are treated as a separate number.

Procedure

In Atlas, go to the Data Explorer page for your project.

If it's not already displayed, select the organization that contains your project from the Organizations menu in the navigation bar.
If it's not already displayed, select your project from the Projects menu in the navigation bar.
In the sidebar, click Data Explorer under the Database heading.
The Data Explorer displays.

Note

You can also go to the Clusters page, and click Data Explorer under the Shortcuts heading.

Click the Create Collection button.

From the Collections screen, click the Create Collection button.

Enter the collection name.

Click the Additional preferences dropdown.

Check the Use Custom Collaton option.

Select a value for locale.

You are required to select a locale from the MongoDB supported languages.

All other collation options parameters are optional. For descriptions of the fields, see Collation.

Click Create Collection to create the collection.

Example

Consider a collection with the following string number and decimal values:

[
  { "n": "1" },
  { "n": "2" },
  { "n": "-2.1" },
  { "n": "2.0" },
  { "n": "2.20" },
  { "n": "10"},
  { "n": "20" },
  { "n": "20.1" },
  { "n": "-10" },
  { "n": "3" }
]

The following find query uses a collation document containing the numericOrdering parameter:

 db.c.find(
  { }, { _id: 0 }
 ).sort(
   { n: 1 }
  ).collation( {
   locale: 'en_US',
   numericOrdering: true
} )

For more information on querying documents in Atlas, see Query Your Data.

The operations returns the following results:

[
   { "n": "-2.1" },
   { "n": "-10" },
   { "n": "1" },
   { "n": "2" },
   { "n": "2.0" }
   { "n": "2.20" },
   { "n": "3" },
   { "n": "10" },
   { "n": "20" },
   {"n": "20.1" }
]

numericOrdering: true sorts the string values in ascending order as if they were numeric values.
The two negative values -2.1 and -10 are not sorted in the expected sort order because they have unsupported - characters.

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Collections

Clustered Collections