Union select null, null, null, null, null, null, null from information_schema.tables.
Даже выражение NULL != NULL не будет истинным, ведь нельзя однозначно сравнить одну неизвестность с другой.
Здесь некоторый SQL, показывающий множество условий и и их эффект, как указано выше. Create table t (x int, y int); insert into t values (null, null), (null, 1), (1, 1); Select 'x = null' as test , x, y from t where x = null union all select 'x != null', x, y from t where x != null union all select 'not (x...
UNION ALL SELECT NULL, *, NULL, NULL FROM email.
Tip: Always use IS NULL to look for NULL values. The IS NOT NULL Operator. The following SQL statement uses the IS NOT NULL operator to list all persons that do have an address
I have a table with a lot of columns and a type column. Some columns seem to be always empty for a specific type. I want to create a view for each type and only show the relevant columns for each type.
Руническая формула (комбинация рун): NULL. 'null' - перевод на Нортумбрийские руны: Download image.
Case Unknown Null предикат IS Null. Предыдущая [Предикат Like].
sex8 cc index php union all select null null null and kzor sa u pictures.
Possible Duplicate: IS NULL vs = NULL in where clause + SQL Server Consider the following code – can someone explain to me why the one query