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 ALL SELECT NULL, *, NULL, NULL FROM email. I understand what this does and why; the hacker needs to create a query that has the same number
(M): SELECT CONCAT(login, password) FROM members. 7. Строки без кавычек Есть несколько
...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.
null - Null против False против 0 в PHP - Qaru.
Viewing and COUNTing the NULLs. Sometimes we might have to do the opposite of what the default functionality does when using DISTINCT and COUNT
I've been asked about counting NULL values several times so I'm going to blog about it in hopes others will be helped by this explanation of NULL values in
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this
In this table I need to select only the ids which have both null and not null marks, and it should not be both not null or both are null in col1.