select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f from table3.
The Background I was trying to solve the fourth realistic mission in hackthissite.org, and couldn't figure out exactly what SQL I should inject into the URL to retrieve the list of emails.
In postgres, I'm getting an error when I try to union two tables where one table has a column (Amount) containing double precision data type...
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
What is the difference between … and … and why does the latter not work?
Then in the second table I have select ..., null as opt from... I know that I could have an empty string with '' as
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...
SQL NULL Values. If a column in a table is optional, we can insert a new record or update an
The IS NOT NULL condition is used in SQL to test for a non-NULL value.
Instead, use WHERE IS NULL or WHERE IS NOT NULL. The definitive guide for data professionals.