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.
I have come across some code that says … What exactly is this doing? Is it getting the field names unitcost and markup? Why would you use "select null as..."? New to this sorry. Thanks.
select cast (2000 as type of quint) from rdb$database select cast (2000 as int) from rdb$database. If TYPE OF is used with a (VAR)CHAR type, its character.
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...
If I have the table … This will display Firstname-Middlename-Surname e.g. … The second one (Jane’s) displays correct, however since John doesn’t have a middlename, I want it to ignore the second dash.
I have a table with three fields, FirstName, LastName and Email. Here's some dummy data: … Now, if I do: … Vitals for Joe is null, as there is a single null field. How do you overcome this behaviour?
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.
What is the difference between … and … and why does the latter not work?
Note: A NULL value is different from a zero value or a field that contains spaces.
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.