select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f from table3.
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...
Нашёл Страную табличку с нат писью привет null null null.
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
Ошибка сайта в данном случае. Но вообще это устройство для безвозвратного слива данных. Типа черной дыры - туда можно кинуть все что угодно и сколько угодно но обратно не вернуть никогда.
/dev/null — специальный файл в Unix-подобных операционных системах. «NUL» — название символа из кодировки ASCII, имеющего код 0 и используемого для обозначения конца строк.
Null — это подтип Variant, который определяет элемент, не содержащий допустимых данных.Null is a Variant subtype
Null values can be used as a condition in the WHERE and HAVING clauses. For example, a WHERE clause can specify a column that, for some rows, contains a null value. A basic comparison predicate using a column that contains null values does not select a row that has a null value for the column.
NULL Macro is simply what is defined as 0 in a macro provided by the library Null pointer is a pointer which has 0 or NULL value stored and points to nowhwere still it points to 0x00 i.e. the first memory location of the OS Null pointer != Uninitialized pointer because an uninitialised pointe…r can point...
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.