MySQL: Finding existences between values in database and array - mysql

Question

I'd like to know how can I make a unique query to find which values exist and which values do not. I explain.
What I have
I've got a database table with a structure as follows:
+----+--------+-----------+-----------+
| id | action | button_id | type |
+----+--------+-----------+-----------+
| 1 | 1 | 1 | button |
| 2 | 2 | 4 | button |
| 3 | 1 | 2 | attribute |
+----+--------+-----------+-----------+
As you can see, an action can have multiple button_id values. For your knowledge, a button_id can be assigned to multiple action, too, but a button_id can only have a type for an action.
So, button_id 1 can be also present in action 4 with the type "attribute" set to it, but it cannot be duplicated to the same action with another type.
The problem
The problem comes when I want to update the buttons in an action. I receive an action object with an array of the buttons it have (in PHP) with the structure below (I write it in JSON structure):
"buttons":
[
{
"id":"1",
"type":"button"
},
{
"id":"3",
"type":"attribute"
}
]
As you can see, the button with ID 1 remains the same, but I've got a new button to deal with (the button with ID 3) and the button with ID 2 is not present anymore.
What I'd want
I'd want to be able to make a unique MySQL query that returns me which values from those I receive exists and which do not, and which may be present in the database but not in that array.
To sum up: I want to know the differences between the buttons in the array received and those present in the database.
So, as an example with the received data described before and the database as we have it right now, I expect to receive something like this:
+--------+-----------+--------+------------+
| action | button_id | exists | is_present |
+--------+-----------+--------+------------+
| 1 | 1 | 1 | 1 |
| 1 | 2 | 1 | 0 |
| 1 | 3 | 0 | 1 |
+--------+-----------+--------+------------+
With this information, I'd be able to know that button with ID 2 does not exist anymore (because it's not present in the new array) and button with ID 3 is a new button because it does not exists previously but it's present in the new array.
What I've tried
There are some tests I've tried, but none of them gives me what I need, and not only tested with MySQL pure queries.
For example, I've tried to check the existence for each button I receive but that would leave me without being able to find if a button is deleted (so it's not present in the received array).
Checking that but taking as reference the buttons in the database has the same effect, as I will be able to check which have been updated or deleted, but it would skip those that are new and not present in the database.
I've tried to write some queries making COUNT queries and GROUP BY button_id, and so, but no luck neither.
(I won't write the queries because none of them have given me the expected results, so they won't be of any help for you).
Any combination of those explained before I think will be much slower than doing it purely by database queries, and that's why I'm asking for it.
The question
Is there a query that would return to me something like the response explained before in "What I'd want" section, so it would make only a call to the MySQL server?
Thank you all for your time, your responses and your patience for any lack of information you may find by my part.
Of course, any doubts, questions you have or information you may need, comment it and I'll try to explain it better or to add it.
Kind regards.

Answer 1

To do that in a single query would be very cubersome. Here is a solution that is not exactly what you are looking for but should do the job.
Let's say your table looks like this :
CREATE TABLE htmlComponent
(
id int auto_increment primary key,
action int,
button_id int not null,
type varchar(20),
dtInserted datetime,
dtUpdated datetime
);
CREATE UNIQUE INDEX buttonType ON htmlComponent(button_id, type);
Now we need to update the table according to the buttons / atributes you have for a specific action.
-- Reset dtInserted and dtUpdated for action 1
UPDATE htmlComponent SET dtInserted = null, dtUpdated = null WHERE action=1;
-- INSERT or UPDATE according to the data inside the json structure
INSERT INTO htmlComponent (action, button_id, type, dtInserted)
VALUES
(1, 1, 'button', NOW()),
(1, 3, 'attribute', NOW())
ON DUPLICATE KEY UPDATE
button_id = VALUES(button_id),
type = VALUES(type),
dtInserted = null,
dtUpdated = NOW();
-- Getting the result
SELECT * FROM htmlComponent where action=1;
Your should end up with this result which will make it easy to figure out what doesn't exists anymore, what is new and what was updated.
+----+--------+-----------+-----------+----------------------------+----------------------------+
| ID | ACTION | BUTTON_ID | TYPE | DTINSERTED | DTUPDATED |
+----+--------+-----------+-----------+----------------------------+----------------------------+
| 1 | 1 | 1 | button | (null) | February, 09 2015 16:21:49 |
| 3 | 1 | 2 | attribute | (null) | (null) |
| 4 | 1 | 3 | attribute | February, 09 2015 16:21:49 | (null) |
+----+--------+-----------+-----------+----------------------------+----------------------------+
Here is a fiddle. Please note I had to put the UPDATE and the INSERT in the left panel because DML are not allowed in the query panel.