Data Primary key vs. Artificial (Autonumber) primary key
On Dec 4, 10:53 pm, Dennis wrote:
ANY data can be used as a Primary Key AS LONG AS you are 100% sure of no
duplication and/or have code in place to prevent such an occurrance.
IIRC a column of type OLEOBJECT cannot be PRIMARY KEY.
Perhaps you meant to say "as long as the engine can be 100% sure of no
duplication"? While I can be sure that I am putting unique values into
a MEMO column, the engine only considers the first 255 characters when
checking a PRIMARY KEY constraint. Also I'd be vary wary of
approximate numeric types (e.g. REAL and FLOAT).
Jamie.
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