In SQL, what kind of value is NULL? How can I check if a field is NULL?

[Tarek Khojah]

Maybe the column holds varchar, maybe it holds int, maybe it holds whatever.

I wanted to check if a value in a given record is NULL, the column holds "long" values, what would be if statement look like? The value the column holds is "long", the column is named "MyColumn".

if (x = resultSet.getLong("MyColumn") ???)

I don't know what condition to test for exactly! Hence the question marks.

[Paul Sturrock]

The code you have written is not SQL, it looks like Java. If this is Java we are talking about, we can check is a variable == null, i.e.:

 
String val = null;
...
if (val == null) {
   // do stuff
}

In SQL you check for null like this:

 
...where [field] is null
 

Remeber that in SQL a value is null, but may not be equal to null.
[ October 16, 2007: Message edited by: Paul Sturrock ]

[Tarek Khojah]

Remeber that in SQL a value is null, but may not be equal to null.

That was my question , let me rephrase it:

Using an if statement in the Java programming language, how can I check if a certain field in my database is null?

[Jeanne Boyarsky]

JDBC provides a method for that:

rs.getXXX(1);
if ( rs.wasNull() )

[edited to fix code tags]
[ October 20, 2007: Message edited by: Jeanne Boyarsky ]

[Tarek Khojah]

Ah, thank you