I have developed a query, and in the results for the first three columns I get NULL. How can I replace it with 0?
What is the difference between … and … and why does the latter not work?
Note: A NULL value is different from a zero value or a field that contains spaces.
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...
When CloseDate is blank, it is NULL. How can I make these two fields be blank for either 01-01-1900 or NULL, yet, still...
In general, R supports: NULL NA NaN Inf / -Inf NULL is an object and is returned when an
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).
select to_date(null) from dual. Про дату - это я в качестве сарказма - в том смысле, что почему именно varchar возвращается когда идет выборка select null as
Null (or NULL) is a special marker used in Structured Query Language to indicate that a data value does not exist in the database. Introduced by the creator of the relational database model, E. F. Codd...