LEVENSHTEIN

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Syntax

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Scalar

levenshtein(left, right [, threshold])

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Arguments

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Returns

• Type: INT
• Possible values: A nonnegative edit distance, or -1 when the distance exceeds threshold.
• NULL behavior: Returns NULL when either string or a supplied threshold is NULL.

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Properties

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Usage notes

• Insertion, deletion and substitution each cost one edit. Distances count Unicode code points.
• A negative threshold causes a non-NULL input pair to return -1.

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Examples

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Typical behavior

SELECT levenshtein('kitten', 'sitting') AS distance, levenshtein('kitten', 'sitting', 2) AS threshold_result;

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Empty and identical strings

SELECT levenshtein('', 'cat') AS insertions, levenshtein('cat', 'cat') AS unchanged;