Explanation of input components in Chapter 16

introduction

In the last article , We introduced ：XML input stream (StAX) Various detailed settings of components , Finally, the actual combat demonstrates how to operate it to read the data on the disk xml file 、 And the operation of cleaning data .

In this article , Let's go on to introduce ：kettle Input components in , Previously, we introduced some common input components . This article expands to explain some uncommon components , These components are very simple to operate , So I'll just show you how to operate , I won't explain the options in detail as before , You can see how to use .

transformation

transformation (transaformation) yes ETL The main part of the solution , It handles extraction 、 transformation 、 Loading various operations on data lines .

Create transformations

What we have to do ETL operation , It's all designed in transformation , So we need to create a transformation first .

Save conversion

Give you a new conversion , Name it , And save

Generate records

brief introduction

You need to turn part of the text data into data lines , Each field acts as a column of a data row , Then you can use this component

Preview the record

Generate random number

brief introduction

In the use of Kettle During data warehousing , It often involves for ID Field generates a unique identifier , and UUID It's usually our choice to generate a unique representation , This is the time to use “ Generate random number ” Functional operators , adopt “ Generate random number ” Can generate UIID.

On a daily basis , Sometimes I just want to test with some data , But I don't want to get it from the database or Excel Input , Then you can generate random numbers .

Preview the record ( Execute many times )

You can see , The result of each run is different , Because every time it's a random number .

Custom constant data

brief introduction

Custom constant data , It's generation key-value Constant data in the form of .

Preview the record

Get system information

brief introduction

System information refers to Kettle Information about the system environment , Include the date of the computer system , Time type information such as week , Computer name 、IP Address 、 Start and end time of conversion or job ( Used for incremental data processing )、 Information about the completion of the previous job and command line parameters, etc .

By obtaining system information components , We can get these data .

choice Type of system information

List Kettle All types of information are supported

Customize several system changes

Preview the record

Conclusion

This article mainly explains ： Generate record component 、 Generate random number components 、 Custom constant data component 、 Get system information components .

As of this article ,kettle Input components for , All the commonly used basics are introduced . The main explanation in the follow-up is ：kettle The output components of .

brother , In fact, there is a distance between thinking and acting , If you think about it, it's gone , But you're doing it , It landed .

Don't say anything , Brothers, follow me and it's over , We still break up the way of kneading to say . The following content is more wonderful , Coming soon , Thank you for your attention ！！