you get data out of the columns using pre-provided methods such as getInt(...), getString(...), but how do you get data out of something like a SELECT statement, in sqlite the statement I'd like to do something like:
SELECT COUNT(COLUMN_NAME) FROM TABLE_NAME
how would you execute this query and then get the result to an int variable?
You do it the same way:
String sql = "SELECT COUNT(COLUMN_NAME) FROM TABLE_NAME";
So if you create a Cursor object with rawQuery():
Cursor c = db.rawQuery(sql, null);
this Cursor contains only 1 column and you can get its value with:
if (c.moveToFirst()) result = c.getInt(0);
where result is a predefined int variable.
But it's a good practice to alias the returned column, like:
String sql = "SELECT COUNT(COLUMN_NAME) AS counter FROM TABLE_NAME";
so you can get it by its name:
if (c.moveToFirst()) result = c.getInt(c.getColumnIndex("counter"));
limit clause and select the last row?
select * from tablename order by id limit 10select * from tablename limit 10. You can do it but there is no guarantee for the result.Create a Dao CLASS which include count method which returns count of the TABLE_NAME
@Dao
abstract class TABLE_NAMEDao : BaseDao<TABLE_NAME> {
@Query("SELECT COUNT(id) FROM TABLE_NAME")
abstract fun count(): Long
}
