|List:||General Discussion||« Previous MessageNext Message »|
|From:||Jay Blanchard||Date:||April 26 2005 3:17pm|
|Subject:||RE: why NOT NULL in PRIMARY key??|
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[snip] The same is true for any other value... Now that the columns have a NOT NULL constraint the records that previously contained NULL now hold '0'. x y x 0 x z x 0 Now, how do you uniquely identify the 2nd and 4th rows? [/snip] The database would have thrown an error when you tried to create row 4.