Bi-sql basic cognition

Little friends who know white tea may know , White tea is not a computer background , Education background . So for tradition IT As far as the knowledge is concerned , White tea has many disadvantages .

From this issue , White tea will be shared SQL Language in PowerBI Application in .

SQL Language has been immersed in the domestic market for many years , It can also be said that if an enterprise does not use PowerBI This is normal , But if you haven't used it SQL That is very few .

therefore , If you want to go further on the road of data analysis , that SQL Language is a barrier that can never be bypassed . Step past , It's the easy way , I can't make it , Then it will stop at PowerBI 了 .

In addition to these practical reasons , Technically speaking ,SQL It is also a basic language that we must master .

• Power Query The short board

From the point of view of data processing ,Power Query It is successful for business users , Because it solves the problem of low code development , so to speak , Even if you haven't learned M Language users , Simple data cleaning can also be realized through simple interface operation .

But from the perspective of data connectivity ,Power Query Just a lightweight processing tool , The unit it faces is M Unit , Some requirements with very large data magnitude , Not recommended in Power Query In dealing with .

• SQL The applicability of

if Excel It is the basic software for business people , that SQL Namely IT The basic software of the crowd . When faced with many demands , It often requires us to understand and master a certain amount of SQL knowledge , Only then can follow-up development be carried out .

A simple example ：

BOSS： that , White tea , Can you extract some data from our company's database for analysis ？

White tea ： Boss , that , I can't ...

friends , The scene above , Is very likely to happen in our work , At this time, if you say no , Embarrassment No ？

• PowerBI Medium SQL

Conventional SQL The language covers a lot of content , Including the establishment of data warehouse , Data storage , Data transmission , As well as internal additions, deletions, changes, and so on .

But in PowerBI in , We only need to master the basic query statements , Basically, we can solve our analysis needs .

Of course , With plenty of time , I suggest you to study systematically SQL.

Begin a formal understanding of SQL, Big guys can ignore the following .

In the data acquisition interface , You can see there's one SQL Server Database connection mode , You can connect to our database here .

• Server address , That is, the address information of the database we want to connect to
• database , This item can be ignored , Without input , Connect to all databases , Input is a specific library
• SQL sentence , Here is what we input SQL The place of language , Tradition SQL Languages can be copied directly here

for instance ：

This is the native database of white tea , Now you want to “FactSales” Import to PowerBI in .

Enter the server address , Database name , And basic query statements .

SELECT * FROM FactSales

Here you will be prompted to enter the access account for white tea , Because it is a local server , Just click on the connection .

You can see that the tables in the database are presented in front of us , You can choose to load directly , You can also choose to convert data .

notes ： The converted data will go directly to Power Query Interface , Study SQL Not to abandon M Language , But to use both , Use whatever works .

Another example ：

It's still this watch , I only need one of them now “UnitPrice” This column , And go to the heavy .

Input SQL sentence .

SELECT DISTINCT UnitPrice FROM FactSales

give the result as follows ：

friends , Isn't it convenient ？ That's all for this issue , White tea will continue to be updated in the future SQL Language in PowerBI Application in .

This is white tea , One PowerBI Beginners .