(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.
If you had SELECT * FROM users and users had 4 columns, the UNION must also have 4 columns. As a result, they just used `NULL values to populate those columns.
99 or 1=1 union select null, concat(table_name,0x0a,column_name) from information_ schema.columns - since where clause cannot be used
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
+and (select 1)=(Select 0xAAAAAAAAAAAAAAAAAAAAA 1000 more A’s). this AAAAA it's more 1000 A. Example in URL
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.
CONCAT() returns NULL if any argument is NULL.
String Functions ASCII Char Charindex Concat Concat with + Concat_WS