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Version: current [24.2.x]


Categories: String


Returns a masked version of a string with the last num_chars characters unmasked. By default, if you do not provide a value, the last four characters are shown.


MASK_SHOW_LAST_N(expression varchar [, num_chars int][, *uc_mask* varchar] [, lc_mask varchar][, *num_mask* varchar]) → varchar

  • expression: The string to mask.
  • num_chars (optional): The number of characters to unmask.
  • uc_mask (optional): Controls the mask character for upper case letters.
  • lc_mask (optional): Controls the mask character for lower case letters.
  • num_mask (optional): Controls the mask character for numbers.


-- xxnn-XXxx-1324
MASK_SHOW_LAST_N example containing optional value
SELECT MASK_SHOW_LAST_N('ab12-ABab-1234', 2)
-- xxnn-XXxx-nn34
MASK_SHOW_LAST_N example containing optional arguments
SELECT MASK_SHOW_LAST_N('Aa12-ABab-1234', 4, 'U', 'u', '#')
-- Uu##-UUuu-1234

Usage Notes

By default, upper case letters are converted to X, lower case letters are converted to x, and numbers are converted to n. You can override the characters used in the mask by supplying optional arguments. The second argument controls the mask character for upper case letters, the third argument for lower case letters, and the fourth argument for numbers.