When you want to replace a possibly null column with something else, use IsNull. SELECT ISNULL(myColumn, 0 ) FROM myTable.
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...
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...
...Null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,concat
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
It should be noted that NULL pointer is different from an uninitialized and dangling pointer.
Этот язык специфичен, но в PHP: Null означает " ничего".
Если инструкция SELECT используется для тестирования на значения NULL в дополнение к
In C, a null pointer constant must be an integer literal with the value 0, or the same cast to type "pointer to void"
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