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
SELECT column_names FROM table_name WHERE column_name IS NOT NULL
SQL Injection Attacks - Macrotone Blogs
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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.
MySQL: IS NULL Condition | Example - With SELECT Statement
This MySQL IS NULL example will return all records from the contacts table where the last_name contains a NULL value.
IS NULL (Transact-SQL) - SQL Server | Microsoft Docs
To determine whether an expression is NULL, use IS NULL or IS NOT NULL instead of comparison operators (such as = or !=).
Работа с NULL-значениями « Язык запросов SQL
NULL может размещаться в поле любого типа. Тем не менее, NULL, как NULL-значение, часто используется в SQL.
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.