select cast (2000 as type of quint) from rdb$database select cast (2000 as int) from rdb$database.
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.
Select char_length(cast('123456789 1' as varchar(10))) from rdb$database. Получаем: Exception ... string truncation Т.е. пробел мы обрезать можем, а другие символы нет.
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...
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)...
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 CAST (miles AS INT) FROM Flights -- convert timestamps to text INSERT INTO mytable (text_column) VALUES (CAST (CURRENT_TIMESTAMP AS VARCHAR(100))) -- you must cast NULL as a data type to use it SELECT airline FROM Airlines UNION ALL VALUES (CAST (NULL AS...
How can I select blank columns as zero? Not sure what you are trying to do. Does this come close? coalesce(nullif(val,''),'0'). Note that "zero" has to be char instead of int.
The SQL Server (Transact-SQL) IS NULL condition is used to test for a NULL value.