如何在Android的sqlite数据库中获得5条最后记录？

Question

Since the db does not have create date and some ordering field (but in my observation the last row is the latest record),

so how can i get the five last record in some condition eg five record that their schoolid == 1?

Thanks

public Cursor select()
{
    String orderBy = FIELD_pubKey+" DESC";
    Cursor cursor = iReadDatabase.query(TABLE_NAME, null, null, null, null, null, orderBy);
    cursor.moveToFirst();
    return cursor;
}

Answer 1

There's no such thing as a last record or a first or a 42nd.

Which records appears last in the result of a query is dependent on the query plan, or an Explicit order by if you add one.

Select * From Table Where ... The rows will be returned in whatever order the engine considers suitable at the time. If you need them in specific order, then add an order by clause to the query, anything else is asking for it.

Something like

Select * From Table Order by SomeColumn desc limit 5

will do what you require.

Now what column you need to order by I've no idea, but you need one that will do the job, assuming automatic primary key, but note it is possible to mess with that.