Question

Guys i have stored a null value in the column of sqlite database

the value that is storing is return "null"

Now using following code to retrieve it

int i = resultSet.getInt(resultSet.getColumnIndex(columnName));
String str = resultSet.getString(resultSet.getColumnIndex(columnName));
boolean bool = resultSet.isNull(resultSet.getColumnIndex(columnName));

if( str == null ) {
    return -1;
}            
return i;

The debugger shows the value of str = "null"

but this condition is not working with str == null , str == "" , str == "null"

anyone can give me a hit of what to do..

Also resultset.isNull gives me a value of false.

So how can i store null in database, secondly if i use “null” then how can i make this condition work.

Answer 1

If you have stored the “null” literal string in the database, you compare against it like so —

if ( "null".equals(str) )

To store a null value in your database table, you use PreparedStatement.setNull()