Dateserial function in default value column

[Gan]

Currently I use dateserial function to convert number to the date/time format
using query and its work.

UPDATE billing SET billing_date =
dateserial(left$(maint_date,4),Mid$(maint_date,5,2),right$(maint_date,2));

But when I put the dateserial function in the default value field

= dateserial(left$(maint_date,4),Mid$(maint_date,5,2),right$(maint_date,2))

an error message 'Type Mismatch' prompted

Anybody can help me regarding this problem

 

[Douglas J. Steele]

Default values cannot be based on other fields.