Apps sqlite query - Max function

[chachiquesi]

Hello,

I've a problem with a query in sqlite3.

The query is very simple:

SELECT MAX (INIT_DATE) INIT_DATE FROM TABLE;

When my application execute this query, and the table is empty, a record is returned. I can't understand why a record is being returned if the table is empty. It should return cero results.

I've tried to execute the query in two different ways:

cursor = db.query(true, "TABLE", new String[] {"MAX(INIT_DATE) AS INIT_DATE"}, null, null, null, null, null, null);

cursor = db.rawQuery("SELECT MAX(INIT_DATE) AS INIT_DATE FROM TABLE", null);

Could anybody help me?

Thanks in advance!

 

[mills2533]

What is the value being returned? Are you sure it isn't a null cursor?

 

[Unforgiven]

I've moved this to the applications development forum as he is where other devs hang out and will be better suited to answer you questions.

 

[Shengxin]

I agree with mills2533. Max is one of the aggregate functions. They always return one record even if the table is empty. For example, count(*) will return 0 if the table is empty.

For a complete list, please refer to SQLite Query Language: Aggregate Functions. As it says, Aggregate max() returns NULL if and only if there are no non-NULL values in the group.

Hope this helps.