>Does anyone know if it is even possible to create a multiple value, character string index, using the date_format function in MYSQL?
>
>I can't seem to get it work with the latest version of MYSQL.
>
>Example:
>CREATE INDEX ACTSTAFFAC ON CONTACTS (ACTSTAFF , date_format(ACTDATE,'%Y%m%d'))

Expressions cannot be used in the indexes, only column names. Why do you need multiple column index in the first place?