Additional SQL functions

Please extend the supported SQL functions in both the data model & analysis model. Some important functions that are missing:

LEN -> counts number of characters in a text

CHARINDEX -> returns the position of a character in a string

PATINDEX -> returns the position of a pattern in a string

LEAD -> access to successor rows based on the offset argument

LAG -> access to previous rows based on the offset argument

ROW_NUMBER -> adds a sequence number within a grouping

DATEDIFF -> returns the difference between two date values

WEEK -> returns the week number for a date

WEEKDAY -> returns the weekday number for a date

QUARTER -> return the quarter of the year for the date

REGEXP_LIKE -> match the input string with the regular expression pattern (true or false)

REGEXP_REPLACE -> replace the string matching a regular expression pattern

REGEXP_SUBSTR -> extract a substring from a string that matches a regular expression pattern