如何在sqlite数据库中查找列的最大值

Question

public Cursor getBiggestInTheColumn() 
{
     return db.query(HEADER_TABLE, null,"MAX(key_Division)", null, null, null, null);
}

我将此方法称为 Cursor cc=db.getBiggestInTheColumn();

但它强行关闭了应用程序.请帮助我

Answer 1

您可以相应地使用simpleQueryForLong和投射它.

public int getMaxColumnData() {

    mDb = mDbManager.getReadableDatabase();
    final SQLiteStatement stmt = mDb
            .compileStatement("SELECT MAX(column) FROM Table");

    return (int) stmt.simpleQueryForLong();
}

Answer 2

public int getBiggestInTheColumn() 
{
    Cursor c = db.query(HEADER_TABLE, null,new String[] {"MAX(key_Division)"}, null, null, null, null); 
    try {
        c.moveToFirst();
        return c.getInt(0);
    } finally {
        c.close();
    }
}