sql - Counting null and non-null values in a single... - Stack Overflow
If that is correct: SELECT count(*) FROM us WHERE a IS NULL UNION ALL SELECT count(*) FROM us WHERE a IS NOT NULL.
sql injection "union select null" - CodeProject
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...
MySQL 8.0 Reference Manual :: B.6.4.3 Problems with NULL Values
mysql> SELECT NULL, 1+NULL, CONCAT('Invisible',NULL)
How to exclude NULL values inside CONCAT MySQL?
If I have this - tadd is the Address table: … Is there a way to exclude the apt_number if it doesn't exist? I was thinking of: … But it will return only those rows with apt_number...
SQL Инъекции | Page 798 | ANTICHAT - Security online community
...function=members&perform=memberappita&entity_id=11+limit+0+UNION+SELECT+1,2,concat_ws(0x3a
Использование значения NULL в условиях поиска | Интерактивный...
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).
SQL NULL Values - IS NULL and IS NOT NULL
Note: A NULL value is different from a zero value or a field that contains spaces. A field with a NULL value is one that has been left blank during record creation!
Заметка про NULL / Хабр
IS NULL вернёт истину, если операнд имеет значение NULL и ложь, если он им не является.
MySQL SQL Injection Practical Cheat Sheet - Perspective Risk
1 UNION ALL SELECT NULL,concat(0x28,column1,0x3a,column2,0x29) FROM database2.table1--. Error Based.
SQL IS NULL | IS NOT NULL: Handling NULL In SQL Correctly
NULL is special in SQL. NULL indicates that the data is unknown, inapplicable or even does not exist. In other words, NULL represents that the data is missing in the database. For example, if an employee does not have any phone number, you can store it as an empty string.