The MASK function extracts characters from or adds characters to an alphanumeric string. It can extract a substring from different parts of the parent string, and can insert characters from a parent string into another substring. For example, it can extract the first two characters and the last two characters of a string to form a single substring.
MASK works by comparing the characters in a mask to the characters in a source field. When it encounters a 9 in the mask, MASK copies the corresponding character from the source field to the new field. When it encounters a dollar sign in the mask, MASK ignores the corresponding character in the source field. When it encounters any other character in the mask, MASK copies that character to the corresponding position in the new field.
MASK replaces the masking functionality of the EDIT function that is available in the reporting language.
Is the source field.
Is a character string enclosed in single quotation marks, or a temporary field that contains the string.
MASK extracts the first initial from the FIRST_NAME field:
The following are sample values for FIRST_NAME and the values for the result of the MASK function:
FIRST_NAME MASK_FIRST_NAME ---------- --------------- MARY M DIANE D JOHN J ROSEMARIE R MARY M BARBARA B
MASK adds dashes to the EMP_ID field:
The following are sample values for EMP_ID and the values for the result of the MASK function:
EMP_ID MASK_EMP_ID ------ ----------- 112847612 112-84-7612 117593129 117-59-3129 219984371 219-98-4371 326179357 326-17-9357 543729165 543-72-9165 818692173 818-69-2173