Welcome back. In this video, you will understand how to use watermarking in database and point operations. So I'll tell you my requirement clearly, I have a table in my database called us product whenever a new product is added into this table, I want a flow to be kicked off and take that new records whatever are added into this table write them to a file, this is very simple. Now what I want an operation database endpoint to pull the database at regular intervals, if there is any new data, new row it should be taken and processed that is my requirement simple. So let us see how to use an operation database module. So a lot of Module Database like this project Right now I am working with Project colors watermarking start project I have added database module here and there is an operation here called us on table row.

This is a very good operation in database endpoint where whenever a row in a table is updated or modified, it will automatically fetch the rows and process it. So I like to configure the connector configuration as usual. I'll select MySQL connection. Then I quickly add the driver as well. driver is I want the version as eight dot zero dot one five. Okay.

Host is localhost 306 is a normal hardcore right now root password is root and the databases mule training deal that protects the connection. Yeah, connection successful. Okay then huh? This will fetch the metadata keys it will fetch all the tables and show me the tables here. Okay, so here is showing these tables should be a table to display switching cables from all the databases right now. Because I used root credentials so that they will name I just select us products are still fitting the metadata let it fetch, I pause the video for some time.

Now I'd select maximizes on table row. Firstly, we'll discuss about some important things I want is on table row to fold the database at a fixed rate of frequency. Or you can call it a cron I want to call it fixed frequency of let's say, five seconds after every five seconds it should start polling the database and I want to start delay of three seconds. Okay. Then to which database table it should pull it should pull for product right what is that yeah product and what is the unique identifier what is the unique column on which I want to store the watermarking beatings. Basically this cracker will use something called as watermark in my earlier videos I have explained you the watermark if you are marking some data, which you should remember from the previous invocation to call such data as watermark or data, okay.

So which column which column value you want to store as watermark the data here to select it. So it should automatically fetch the columns and show me It may take some time to resolve but I'll cooperate product transfer ID is what I want. For instance, ID is a primary key product underscore, Id products underscore. And in this table what is the ID column I want the same one, I'll give a symbol underscore i. So that's all I know whatever new products are coming I want to write to fail. So I'll add the file module also.

Then I will drag and drop right operation And to which folder I want right I'll show but before that connector configuration here are you in C drive in Cedar, I have files argue this as my working directory then yeah, you're in this working round write files to output slash or ducks dot CSV file. I want to write a CSV with what contents here the content is written us. payload what our is the lapel But now, what are the data I'm getting from database, I want to convert it to CSV. So what I will do is I'll just drag and drop, transform my search component to convert, right a CSV. Okay. So here, I will just write as this line application slash CSV.

Then I don't want header. I don't want header I'll say head is equals to false. We'll simply I will write here in an array pillow. Don't worry about this complex CSV transformation law. This dw will expression will transform the data from database to a CSV and I don't want headers to be included every time and in the right operation. In a file What I want is I want right more to be append.

So, any new records should be append Alright. So now let me run this projects okay the project got deployed and like to check if the file is created the output products or CSV is created. Yep. I can see that these are the things right so whatever are there my data was there written and closes and the delete the file. Okay, now I will restart my application. Actually, in my own table row, I configured this on table row component to do watermarking using product ID right actually what we'll do is once it finds a query, the last value of the last product ID is stored inside something called as an object store.

So in mule, we use something called an object store to put some key value pairs. Basically, in this case, the last product ID is stored in objects or with keys or ID, and the value is lost product ID. Okay, so the value of product It is watermark lysing. Now, I will run this project again. I want to see if the file will get regenerated again. Since I actually stopped the application and restarted if the watermark data is in memory then after a restarted again is to firstly poll and write a new fresh file.

But if the watermark or data is persisted, then when I restarted the same persisted watermark, the data should be loaded. And I should observe that the new file is not written is it? So, let's check if it will happen as expected. I expect that the file should not be written. Okay. All right.

Let me check output folder is our products, our CSV right now. Now that means the watermark data is not in memory. It is persistent. But where does it happen? Where is it persistent. It's actually if you see this is my mule folder, mule homerun directory, I will go to this home directory.

If you see there is.mil folder which contains the metadata of the running instance. Here you can see there is a project watermarking stuck. Here there's a folder called object store, which contains the data whatever my application is writing to object store. The object store details whatever watermarking details are returned to the object store in our application. They will be returned or some files here. Right, so we don't have one.

Now during development, I want the files to be reprocessed. I want this metadata to be here. So you know already I have told you in my earlier video, but quickly to repeat, what I will do is right now, I'll show you how to clear the mandate of the application, right click on the project. Earlier, we used to run as mule application. Now I'll select Run as mule application, configure. If it come down, there's an option clear application at a prompt, by default was never to never clear the application data.

Now it's a prompt, and I'll apply and run now. Let us see. See now it's prompting. Do you want to clear the application data? Yes. Let it get deployed.

Once it gets deployed. Again, this table row should pull the database get the records. And those records. Since the watermark is lost, those new records have to be returned to the flat file. Right. So let me just check the output folder in the meanwhile, so I'll go to C drive.

By outworks. The file is not generated. I think the applications getting still deployed. Yep, the application is still getting deployed. Let me just wait. See the folder is empty.

I think three seconds have given us start time. Yep. Now the file is created. It will contain the records from the database, right. So now you know To create the watermark or data, clearly I want to tell you what is watermarking watermarking means remembering the previous state. Normally, whatever data we want to remember, will keep it in object store in mule, even though this in this case also the on table row is actually keeping the last product ID in the object store.

In object store we can store key value pairs The key is whatever column name and the value is a column value. Okay, so now you understood how watermarking works in this case. In the next video, we are going to I'm going to show you how to create your own watermarks. But before you go to the next video, there is one lab exercise which are to do open this document. 07 watermarking and there is step one, which shows you how to actually configure the application to use watermarking. Go through this step one, see you next video.