Android - How can I pass data related to two tables to a the insert method of a Content Provider

Question

I need to insert data related to an Order and its corresponding Detail.

Without a ContentProvider I would do something like this:

public boolean insertOrder(Order order, ArrayList<OrderDetail> items) {
    boolean wasSuccessful = false;
    ContentValues cvOrder = new ContentValues();
    cvPedido.put(ORDER_CUSTOMER_ID, order.getCustomerId());
    cvPedido.put(ORDER_CUSTOMER_NAME, order.getCustomerName());     
    String insertQuery = "INSERT INTO " + ORDER_DETAIL_TABLE
            + " VALUES (?,?)";
    //...
    try {

        this.openWriteableDB();
        SQLiteStatement statement = db.compileStatement(insertQuery);
        db.beginTransaction();
        long idOrder = db.insertOrThrow(ORDER_TABLE, null, cvOrder);
        if (idOrder > 0) {


            for (int i = 0; i < items.size(); i++) {    
                OrderDetail detail=items.get(i);
                statement.clearBindings();
                statement.bindString(1, detail.getDescription);
                statement.bindDouble(2, detail.getPrice);
                //...
                statement.execute();
            }
            db.setTransactionSuccessful();
            wasSuccessful = true;               
        }

    } finally {
        db.endTransaction();
        this.closeDB();
    }
    return wasSuccessful;
}

The problem is that now I want to use a ContentProvider and I don't know what to do with this kind of cases where data about two or more tables must be passed to a single CRUD operation, knowing that a insert operation only accepts two parameters :

 @Override
    public Uri insert(Uri uri, ContentValues values) {

    }

What do you do in a ContentProvider when you have to insert relational data in a transaction?

Thanks in advance.

Answer 1

You should use ContentProviderOperation. Since it's your ContentProvider you can assure that applyBatch() will execute all operations within a transaction. All standard content providers also ensure that that's the case.

See my blog post about ContentProviderOperation in general and my other post about how to use withBackReference() to access results of previous operations - which you need to access the orderId.

One important caveat: All ContentProviderOperations of one batch must use the same authority - but can use different URIs! In your case that should be no problem.

Answer 2

You can put all the data into a ContentValues and have a provider. You'll have to get a little creative with the order details.

Below psuedo code I create a key "DETAIL" on the fly with a integer then the item.

           ContentValues values = new ContentValues();
            values.put(ORDER_ID,orderid);

           for (int i = 0; i < items.size(); i++) {    
            values.put("DETAIL" + Integer.ToString(i),items.get(i));
            }

            Uri uri = context.getContentResolver().insert(
                    ORDER_URI, values);

Then in content provider you sort it out.

@Override
public Uri insert(Uri uri, ContentValues values) {

    int uriType = sURIMatcher.match(uri);
    SQLiteDatabase sqlDB = database.getWritableDatabase();
    long id = 0;
    switch (uriType) {
    case ORDER:
        // trim name and description
        trimNameDescriptions(values);
        try {
            id = sqlDB.insertOrThrow(ORDERS_TABLE,
                    null, values);
        Integer i =0;
        do (values.containsKey("DETAIL" + i.toString()){
        ContentValues v = new ContentValues();
        v.put("DETAIL",values.get("Detail" + i.toString()));
        v.put("ORDERID",id);
          //ACTUALLY CALL THE INSERT METHOD OF THE PROVIDER
        insert(DETAIL_URI,v);
         i+=1;
     }

Answer 3

You can design content provider to mirror your SQLite tables, and use insertOrder code same as above.

Just use insert of content providers for each table(uri), to perform similar operations as in your insertOrder method

Another option is to define your content provider URI to take combination of your Order and items , and implement the parsing yourself in the content provider before committing to underlying data model.