Android sqlite query

Question

Cursor cursor = db.rawQuery("SELECT id,lastname FROM people WHERE lastname=null; ",null);

this query does not return the members whose lastname is empty. What is wrong with that query ? Should I check like that WHERE lastname="" ?

A comment since I'm not sure exactly what you're doing: if you're trying to access the Contacts database, you should be using the built in ContentProvider classes. They're the recommended way to handle this in Android. — Codeman
– Codeman, Commented May 21, 2012 at 19:28
There are some simple implementations of SQL Lite for your PC. Much quicker to test and debug queries than compiling and testing you Android app... — Simon
– Simon, Commented May 21, 2012 at 19:33

Alex Lockwood · Accepted Answer · 2012-05-21 19:43:19Z

5

Try this instead:

    ... WHERE lastname IS NULL;

Alex Lockwood

83.3k39 gold badges209 silver badges250 bronze badges

answered May 21, 2012 at 19:28

Nick

6,3955 gold badges38 silver badges54 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Alex Lockwood · Accepted Answer · 2012-06-09 18:49:22Z

1

It is not possible to test for NULL values with comparison operators, such as =, <, etc.

You have to use the IS NULL and IS NOT NULL operators instead.

SELECT id, lastname FROM people WHERE lastname IS NULL;

answered May 21, 2012 at 19:31

Alex Lockwood

83.3k39 gold badges209 silver badges250 bronze badges