a common table expression. LEVEL has the value of 1 on the first iteration
and successively larger integer values of subsequent iterations. It cannot
have a table qualifier. Actual columns named "level" can still be accessed
by including the table name qualifier.
FossilOrigin-Name: cc1cb3217800ff666a00bf4f544a5a477589bc1b
an arbitrary expression and not simple the constant NULL. They work like
= and <> except that NULL values compare equal to one another an unequal to
everything else.
FossilOrigin-Name: 98853f6104076c50ea92175e17a3254bfbbd4619
allowed but never worked, so this should not present compatibility problems.
Other internal grammar simplifications. (CVS 5546)
FossilOrigin-Name: 4cedc641ed39982ae8cbb9200aa1e2f37c878b73
