MASK

Returns a masked version of a string.

Syntax

MASK(expression varchar, uc_mask varchar, lc_mask varchar, num_mask varchar) → varchar

• expression: The string to mask.

• uc_mask: Controls the mask character for upper case letters.

• lc_mask: Controls the mask character for lower case letters.

• num_mask: Controls the mask character for numbers.

Examples

MASK example

SELECT MASK('abcd-ABCD-1234')
-- xxxx-XXXX-nnnn

MASK example containing optional arguments.

SELECT MASK('abcd-ABCD-1234', 'U', 'u', '#')
-- uuuu-UUUU-####

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 first argument controls the mask character for upper case letters, the second argument for lower case letters, and the third argument for numbers.