sql - Union to handle NULL values - Stack Overflow
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.
SQL using If Not Null on a Concatenation - Stack Overflow
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.
sql - CONCAT'ing NULL fields - Stack Overflow | Post as a guest
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?
Confusing SQL error in SELECT NULL, *, NULL, NULL - Stack Overflow
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.
oracle10g - Oracle: Concat with delimiter, but only if... - Stack Overflow
I want to select a concatenation of a couple of fields, but with a separator between them. The separator should only be there if both operands are not null.
Sqlmap: SQL-инъекции - это просто - «Хакер»
Классический вариант внедрения SQL-кода, когда в уязвимый параметр передается выражение, начинающееся с «UNION ALL SELECT».
SQL is null and = null - Stack Overflow
What is the difference between … and … and why does the latter not work?
SQL Injection Cheat Sheet | Netsparker
SELECT header, txt FROM news UNION ALL SELECT name, pass FROM members This will combine results from both news table and members table and return all of them. Another Example: ' UNION SELECT 1, 'anotheruser', 'doesnt matter', 1--. UNION – Fixing Language Issues.
SQL NULL Values - IS NULL and IS NOT NULL
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
Заметка про NULL / Хабр
Даже выражение NULL != NULL не будет истинным, ведь нельзя однозначно сравнить одну неизвестность с другой. Кстати, ложным это выражение тоже не будет, потому что при вычислении условий Oracle не ограничивается состояниями ИСТИНА и ЛОЖЬ.