MASK

Description

The MASK function is to shield data to protect sensitive information, and it is commonly used in data anonymization scenarios. Its default behavior is to convert a uppercase letter in the input string to X, a lowercase letter to x, and a number to n.

Syntax

MASK(<str> [, <upper> [, <lower> [, <number> ]]])

Parameters

Parameter	Description
<str>	String that need to be masked
<upper>	Optional Parameter, replaces uppercase character to X by default. If a sequence of characters are input, the first character will be taken, and if non ASCII characters are input, the first byte will be taken
<lower>	Optional Parameter, replaces lowercase character to x by default. If a sequence of characters are input, the first character will be taken, and if non ASCII characters are input, the first byte will be taken
<number>	Optional Parameter, replaces numeric character to n by default. If a sequence of characters are input, the first character will be taken, and if non ASCII characters are input, the first byte will be taken

Return Value

Returns a string after masking uppercase character, lowercase character and lnumeric character. Special cases:

• If any Parameter is NULL, NULL will be returned.
• Non-alphabetic and non-numeric characters will do not masking

Examples

select mask('abc123EFG');

+-------------------+
| mask('abc123EFG') |
+-------------------+
| xxxnnnXXX         |
+-------------------+

select mask(null);

+------------+
| mask(NULL) |
+------------+
| NULL       |
+------------+

select mask('abc123EFG', '*', '#', '$');

+----------------------------------+
| mask('abc123EFG', '*', '#', '$') |
+----------------------------------+
| ###$$$***                        |
+----------------------------------+