Top "Null" questions

Should a retrieval method return 'null' or throw an exception when it can't produce the return value?

I am using java language,I have a method that is supposed to return an object if it is found. …

java exception error-handling null

Best way to check for null values in Java?

Before calling a function of an object, I need to check if the object is null, to avoid throwing a …

java null nullpointerexception

object==null or null==object?

I heard from somebody that null == object is better than object == null check eg : void m1(Object obj ) { if(null == …

java null

Explicitly set column value to null SQL Developer

I am new to Oracle DB and I am using Oracle SQL Developer (Ver 3.0.02) to query the DB. I wanted …

oracle null oracle11g oracle-sqldeveloper plsqldeveloper

SQL Server String Concatenation with Null

I am creating a computed column across fields of which some are potentially null. The problem is that if any …

sql-server null string-concatenation calculated-columns

MySql Query Replace NULL with Empty String in Select

How do you replace a NULL value in the select with an empty string? It doesnt look very professional to …

mysql string replace null

JavaScript check if value is only undefined, null or false

Other than creating a function, is there a shorter way to check if a value is undefined,null or false …

javascript null undefined

How do I get SUM function in MySQL to return '0' if no values are found?

Say I have a simple function in MySQL: SELECT SUM(Column_1) FROM Table WHERE Column_2 = 'Test' If no entries in …

mysql function null sum

Null vs. False vs. 0 in PHP

I am told that good developers can spot/utilize the difference between Null and False and 0 and all the other …

php null

Do you use NULL or 0 (zero) for pointers in C++?

In the early days of C++ when it was bolted on top of C, you could not use NULL as …

c++ null