SQL using If Not Null on a Concatenation - Stack Overflow
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.
sql injection "union select null" - CodeProject
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...
Использование значения NULL в условиях поиска | Интерактивный...
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).
SQL NULL Values - IS NULL and IS NOT NULL
Note: A NULL value is different from a zero value or a field that contains spaces. A field with a NULL value is one that has been left blank during record creation!
Sum of a column with NULL values
I need a query which will return null while doing sum(fieldA) in sql server
SET CONCAT_NULL_YIELDS_NULL in SQL Server
CONCAT_NULL_YIELDS_NULL control whether concatenation results shall be treated as NULL or empty string values.
Работа с NULL-значениями « Язык запросов SQL
Тем не менее, NULL, как NULL-значение, часто используется в SQL. Предположим, появился покупатель, которому еще не назначен продавец.
SQL IS NULL | IS NOT NULL: Handling NULL In SQL Correctly
NULL is special in SQL. NULL indicates that the data is unknown, inapplicable or even does not exist. In other words, NULL represents that the data is missing in the database. For example, if an employee does not have any phone number, you can store it as an empty string.
NULL Values In SQL | SQL UNION Clause - DataFlair
In general, every NULL value is taken into account to vary from each alternative NULL in the database.
SQL: IS NULL Condition
The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE.