The ML.NGRAMS function

This document describes the ML.NGRAMS function, which lets you create n-grams of the input values.


ML.NGRAMS(array_input, range [, separator])


ML.NGRAMS takes the following arguments:

  • array_input: an ARRAY<STRING> value that represent the tokens to be merged.
  • range: an ARRAY of two INT64 elements or a single INT64 value. If you specify an ARRAY value, the INT64 elements provide the range of n-gram sizes to return. Provide the numerical values in order, lower to higher. If you specify a single INT64 value of x, the range of n-gram sizes to return is [x, x].
  • separator: a STRING value that specifies the separator to connect two adjacent tokens in the output. The default value is whitespace .


ML.NGRAMS returns an ARRAY<STRING> value that contain the n-grams.


The following example outputs all possible 2-token and 3-token combinations for a set of three input strings:

  ML.NGRAMS(['a', 'b', 'c'], [2,3], '#') AS output;

The output looks similar to the following:

|        output         |
| ["a#b","a#b#c","b#c"] |

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