How to use 'not like' operation in X++ SQL

From http://fredshen.spaces.live.com/blog/

In X++, we can use Like '*someIdentifier' to implement the Like keyword.
e.g.

    select firstonly purchTable
        where purchTable.purchId like '00007*';

 

However if you want to use 'Not Like' in X++ SQL statement, you have three options:
The first option, using '!' as 'not',
e.g.

    select firstonly purchTable
         where !(purchTable.purchId like '00007*');

 

The second option, using notExists join
e.g.
    PurchTable purchTable, refPurchTable;
    ;

 

    select firstonly purchTable
        notExists join refPurchTable
        where purchTable.purchId == '00007*';

Please make sure that you do put purchTable.purchId in condition statement, otherwise the SQL statement will retrieve an empty result set.

The last option, using Query
e.g.
    Query query = new Query();
    QueryRun queryRun;
    ; 

    query.addDataSource(tableNum(PurchTable)).addRange(fieldNum(PurchTable, PurchId)).value('!00007*');
    queryRun = new QueryRun(query);

    if(queryRun.next())
    {
        purchTable = queryRun.get(tableNum(PurchTable));
        print purchTable.PurchId;
        pause;
    }

 

Using NotExists join seems more complicated than the first option, but actually there is no performance difference between them.