(select 1 from(select count(*), concat(( select( select unhex(hex
select number, text from test_table union all select number, text from test_table_2. Здесь уже вывелись все строки, так как мы указали union all. А теперь давайте рассмотрим, какие могут быть ошибки даже в этом простом запросе.
99 or 1=1 union select null, concat(table_name,0x0a,column_name) from information_ schema.columns - since where clause cannot be used
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
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...
select, is obvious. null, is just a place holder that is used because a union statement requires that the number of fields match the 1st query that it’s appending to.
SELECT CONCAT("SQL ", "Tutorial ", "is ", "fun!") AS ConcatenatedString; Try it Yourself ». Definition and Usage. The CONCAT() function adds two or more expressions together. Note: Also look at the CONCAT_WS() function. Syntax.
If the separator is NULL, the result is NULL. mysql> SELECT CONCAT_WS(',','First
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
SELECT * FROM news WHERE id_news = 5. Но если злоумышленник передаст в качестве параметра id строку -1 OR 1=1 (например