Apps sqlite query random example

[ronnixw]

Hello,

can you please show me an example how to select random rows from database using :
db.query(table, columns, selection, selectionArgs, groupBy, having, orderBy)

best regards,
Uldis

 

[miXer]

Random r = new Random();
db.query(true, DB_TABLE, new String[] { "_id" }, "_id = ?", new String[] { String.valueOf(r.nextInt(100)) }, null, null, null, null);

 

[ronnixw]

Thank you , but if I am true , this is not the way I was asking for.
I wanted sqlite variant not java.

If I understand by using this method , I need to know how much records are into database and they must be without gaps between them?!
And this query will return one row or row group?

best regards,
ronnixw

 

[miXer]

You asked for this method in your question, and this gives you a random row. To get the row count so you dont get IndexOutOfBounds use this:

Random r = new Random();
db.query(true, DB_TABLE, new String[] { "_id" }, "_id = ?", new String[] { String.valueOf(r.nextInt(getRowCount())) }, null, null, null, null);

private int getRowCount()
{
    Cursor c = db.query(DB_TABLE, new String[] { "_id" }, null, null, null, null, null);
    int count = c.getCount();
    c.close();
    return count;
}

 

[GIR]

Search google for the 'Random Quotes' example, it uses SQLite and has code examples that do this very task.

From what I currently understand the java code in an android app seems to 'wrap up' the sql commands. I may be wrong, if so please correct me.

 

[ronnixw]

You asked for this method in your question, and this gives you a random row.

Sorry , I asked for random rowS , it means one query return more than one row in random order

Didn't find better solution than just execute plain sql code