Re: Document NULL

hi.

"SQL specification" should be "SQL standard"?

+   another null vale and unequal to all other values.
typo. should be "another null value"

other places using subsection, many places in doc/src/sgml/nullvalues.sgml
using "sub-section".

+   Notice two important behaviors: first, even though we passed in a
null value to
+   to the <literal>set_config</literal> function, the
<literal>current_setting</literal>
there is two "to to".

gmail has grammar checks, chatgpt can also help find typos.
you can give it a try.


+   <programlisting>
+    BEGIN;
+    ALTER TABLE null_examples ADD CONSTRAINT value_not_1 CHECK (value != 1);
+    ROLLBACK;
+   </programlisting>
+   <screen>
+    BEGIN
+    ERROR:  check constraint "value_not_1" of relation
"null_examples" is violated by some row
+    ROLLBACK
+   </screen>
+   <programlisting>
+    BEGIN;
+    ALTER TABLE null_examples ADD CONSTRAINT value_not_10 CHECK (value != 10);
+    ROLLBACK;
+   </programlisting>
+   <screen>
+    BEGIN
+    ALTER TABLE
+    ROLLBACK
+   </screen>

i think this part, BEGIN... ROLLBACK is not necessary.
since if we add these check constraints, it won't influence the
later(next) section.