As shown below, I need not null values to be at the start of all output fields.
If I have the table … This will display Firstname-Middlename-Surname e.g. … The second one (Jane’s) displays correct, however since John doesn’t have a middlename, I want it to ignore the second dash.
Then in the second table I have select ..., null as opt from... I know that I could have an empty string with '' as opt however, I don't want an empty string, I really do need it to be null.
var lineOptions: PolylineOptions? = null. val markerOptions = MarkerOptions().
I have a table with three fields, FirstName, LastName and Email. Here's some dummy data: … Now, if I do: … Vitals for Joe is null, as there is a single null field. How do you overcome this behaviour?
What is the difference between … and … and why does the latter not work?
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...
Note: A NULL value is different from a zero value or a field that contains spaces.
Классический вариант внедрения SQL-кода, когда в уязвимый параметр передается выражение, начинающееся с «UNION ALL SELECT». Эта техника работает, когда веб-приложения напрямую возвращают результат вывода команды SELECT на страницу: с использованием цикла for или...
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).