How to create sequential number but not ROWID in Android SQLite database?

Question

I am working on an app which contains an Android SQLite database. I add and delete rows in this database. When I delete my row, it is based on the ROWID. But I found out, that despite I delete the row, the ROWID remains. So for example if I have 3 rows in my database and delete the 2nd row, my third row will not change to 2 it remains 3. Then if I add a row, it will be 4.

So my question is, how to do that when I delete a row, and add a new one then the number of the added row would equal to the deleted row. So for example if I delete the first row, than the database will show me next to the other rows 1,2,3... and not 2,3,4...

Sorry, maybe it is a little bit complicated, but I hope it makes sense.

Here is my code:

public HotOrNot open() throws SQLException{
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}

public long createEntry(String name, String hotness) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_HOTNESS, hotness);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}

public String getData() {
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_HOTNESS};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";

int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iHotness = c.getColumnIndex(KEY_HOTNESS);

for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
    result = result + c.getString(iRow) + " " + c.getString(iName) + " " + c.getString(iHotness) + "\n";
}
return result;
}

public String getName(long l) throws SQLException{
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_HOTNESS};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "=" + l, null, null, null, null);
if(c != null){
    c.moveToFirst();
    String name = c.getString(1);
    return name;
}
return null;
}

public String getHotness(long l) throws SQLException{
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_HOTNESS};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "=" + l, null, null, null, null);
if(c != null){
    c.moveToFirst();
    String hotness = c.getString(2);
    return hotness;
}
return null;
}

public void updateEntry(long lRow, String mName, String mHotness) throws SQLException{
// TODO Auto-generated method stub
ContentValues cvUpdate = new ContentValues();
cvUpdate.put(KEY_NAME, mName);
cvUpdate.put(KEY_HOTNESS, mHotness);
ourDatabase.update(DATABASE_TABLE, cvUpdate, KEY_ROWID + "=" + lRow, null);
}

public void deleteEntry(long lRow1) throws SQLException{
// TODO Auto-generated method stub
ourDatabase.delete(DATABASE_TABLE, KEY_ROWID + "=" + lRow1, null);
}
}

I know that it can't be done using ROWID, because it is unique for each row. Could you please write the code how to solve this problem, because I am beginner in Android and also in SQLite.

Thanks in advance

Answer 1

SQLite keeps track of the largest ROWID that a table has ever held using the special SQLITE_SEQUENCE table.

You can update SQLITE_SEQUENCE table-

UPDATE SQLITE_SEQUENCE SET seq = <n> WHERE name = <table_name>

n is the rowid - 1

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