Syntax for a Function called in an Update Query and how to insert the desired task in the function.

Question

In the middle of an Update Query, I want to run a function that should return a value depending on the task. The task performed is the date field of this row.

The Function Name is "BeforeDate"

StringSQL= "Update Table SET Table .Period = " & BeforeDate("Table.[Date]")

If I write the above code to return the desired value, I get the following error message:

"System.InvalidCastException: 'Conversion from string "Table.[Date]" to type 'Date' is not valid.'"

What is the proper syntax to accomplish the above?

Answer 1

Now I Change it
for 3 update Query's
Without the function

Answer 2

now I changed the Quary Like this
StringSQL = "Update Table SET Table.Period = {BeforeDate(Table.[Date])}"
StringSQL &= " WHERE (((Table.[Date]) < #{BeforeDate(Table.[Date])}#) "

I Added { }

And i got a error

System.Data.OleDb.OleDbException: 'Malformed GUID. in query expression '{BeforeDate(Table.[Date])}'.'