On 12/13/2012 5:32 AM, seiliki@so-net.net.tw wrote:
> I am trying to implement a mechanism that prohibits the last row of a data set from being deleted.
>
> CREATE TABLE t1 (c1 INTEGER,c2 INTEGER, PRIMARY KEY (c1,c2));
>
> INSERT INTO t1 VALUES (1,1),(1,2),(1,3),(2,1),(2,2),(2,3);
Which row is the last row? relations are sets, not ordered lists.