Transaction, what is a transaction?
We hear this a lot in databases, a transaction, it's nothing but a bunch of queries.
OK, it's a collection of queries.
So it's a one or more queries game.
And that property of these queries or they are you one unit of work?
An example would be if you want to deposit an account.
Right.
And some cash into an account that is actually a select statement followed by a statement followed by
another update, something like we now we're going to show in the second round.
But each one of those is a query.
The three of them can form a transaction and you define what a transaction begin and where transaction
end.
And we also there is another semantic attached to a transaction like a commit.
Hey, I am happy with my changes.
Go persist them, commit that sort of commitment, roll back.
You know what I think something went wrong.
Roll back, abort, abort, abort.
So that's another two piece of concept then attach by a transaction.
We know that.
Let's just jump into example.
A transaction.
I have an account here with a beautiful table just to feel because that's all where you need obviously
for in a bank or I have to.
Still feels like you don't need a name.
You don't need anything else.
No data, no.
Just do field.
So there's I got the idea there is a balance.
This guy has a thousand dollars, guys added to five, five hundred.
And the transaction is send hundred dollars from account one to account to us.
So what do we need to do first.
Does account one even have a hundred dollar.
I don't know.
So I need to check to us, we're going to begin the transaction, get a select let's check the balance.
Do you have one hundred dollars that.
Yes.
Your balance is a balance.
Go to the 100 yard sir.
It is greater than a hundred.
All right.
Let's debit that hundred minus hundred.
OK, so now it's nine hundred.
OK, but that's not committed is just the math, right?
It's just touched.
It's a dirty change game.
And then I'm going to add another hundred to the second account.
I'm going to commit my changes.
Turning green.
I mean, this is like it's persisted.
All good.
We're happy and that's it.
OK, so that's essentially what a transaction is.
It's a unit of work, but it consists of multiple queries, one or more as a transaction.