... cast(0x393133353134353632332e39 as char)-- · 999999.9 /union/)/**/union/**/all/**/select/**/null--/**/zini/all /select /cast(0x393133353134353632312e39 as char) ...
As a result, they just used `NULL values to populate those columns. the real confusion is in the CONCAT(). They are combining 126, 39, database name as hex
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this
999999.9 union all select cast0x393133353134353632312e39 as char and 0=0. Relevance Best Sellers Price: Low to High Price: High to Low Top Rated Most Rated Brand: A to Z Brand: Z to A Newest.
Union select null, null, null, null, null, null, null from information_schema.tables. for a small database containing three tables. this instruction is used in sql injection I tried it and it worked but I didn't really know how it works can somebody help me...
Предикат IS NULL позволяет проверить отсутствие (наличие) значения в полях таблицы. Использование в этих случаях обычных предикатов сравнения может привести к неверным результатам, так как сравнение со значением NULL дает результат UNKNOWN (неизвестно).
In general, every NULL value is taken into account to vary from each alternative NULL in the database.
Даже выражение NULL != NULL не будет истинным, ведь нельзя однозначно сравнить одну неизвестность с другой. Кстати, ложным это выражение тоже не будет, потому что при вычислении условий Oracle не ограничивается состояниями ИСТИНА и ЛОЖЬ.
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The null character (also null terminator or null byte) is a control character with the value zero. It is present in many character sets, including ISO/IEC 646 (or ASCII), the C0 control code, the Universal Coded Character Set (or Unicode), and EBCDIC.