select cast (2000 as type of quint) from rdb$database select cast (2000 as int) from rdb$database. If TYPE OF is used with a (VAR)CHAR type, its character.
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.
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.
2018-12-04 {\x22visitorId\x22: null, \x22pageSize\x22: 36, \x... 2018-12-04 i \x63\x61nt ti\x65n ti\x65n 2018-12-04 \x2f\x01\x69\163\151\x62\x69\154it\171 2018-12-04 \x65m ko th\x65 \.
Ken Sanchez NULL * Terri Duffy NULL * Roberto Tamburello NULL * Rob Walters NULL * Gail Erickson
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...
The IS NULL operator is used to test for empty values (NULL values). The following SQL lists all customers with a NULL value in the "Address" field: Example. SELECT CustomerName, ContactName, Address FROM Customers WHERE Address IS NULL
The null character (also null terminator or null byte), abbreviated NUL or NULL, is a control character with the value zero. It is present in many character sets, including ISO/IEC 646 (or ASCII)...
In general, R supports: NULL NA NaN Inf / -Inf NULL is an object and is returned when an expression or function results in an undefined value.
The Oracle IS NOT NULL condition is used to test for a NOT NULL value.