Why SQL is Still important even if you use power BI
These days lot of folks says :" now we have Power BI , Tableau than why we need to learn SQL?"
this question is very common for beginners.
here we will try to understand from scratch that why SQL is important even we have Power BI and how we can use both together.
First Will Understand What POWER BI does?
Power BI is a data visualization tool , Means:
-->Showing Data in charts
-->creating reports
-->creating Dashboards.
Power BI can show us for eg :
-How many Sales were there
-which product is on top,
-is the trend going up or down?
but remember Power BI don't create data itself, it gets data from somewhere else.
and this is where SQL is entered.
What SQL Does( in very simple term)
SQL's job is to :
Extract data from a database.
cleanse data
If Power BI is TV screen, SQL is the remote that lets you decide:
what will be visible
what will not be visible
What Problem arise in power BI without SQL?
In starting , People think :
"we can filter , sort, and calculate everything directly in power BI
But as the data grows larger , problems start appearing.
too much data gets loaded
if you load the entire table into power BI:
-the report becomes slow
-refresh time increases
-The System starts to hang
With SQL, you can do this in advance:
-Select only the required columns
-Filter only the required rows.
SQL makes data "easy to understand"
Database data is often:
Messy
duplicate
In a raw format
Power BI Shows data,
but SQL Prepares the data.
Using SQL, we can:
-Remove extra columns
-Eliminate incorrect records.
-Convert data into summaries
Power BI will look good only when the data is good.
SQL vs Power BI calculations
Power BI has calculations(DAX),
but it is not always right to do every calculation there.
Why are calculations better in SQL?
-SQL calculations happen at the source level
-Calculate once -> reuse in every report
performance is better
for eg :
total counts
Grouped data
Basic averages
SQL = Strong foundation
Power BI = presentation layer
Why is Power BI alone not enough?
it is very powerful, but:
-it does not teach data modeling
-it does not teach database logic
BY learning SQL:
you understand how data is connected
Relationships between tables become clear
your logical thinking becomes stronger
good power bi developers usually know SQL as well.
How does SQL help at the beginner level?
if you are new, SQL teaches you:
-How to think about data
-how rows and columns work
How filtering and counting are done
These Concepts are directly used in Power BI as well. Learning SQL makes learning power BI easier.
As you progress further:
Multiple tables come into picture
large datasets appear
performance starts to matter
At this level : SQL queries are optimize and power bi focuses mainly on visualization
FOr eg:
imagine you you are cooking food
SQL - chopping vegetables, cleaning them , preparing spices
Power BI= plating and presenting the dish
if the preparation is not right,
no matter how good the presentation is , the taste will not be good.
Conclusion
SQL is still essential,
because Power BI depends on data.
if you know only Power BI:
-you can build solutions
In the beginning SQL may feel difficult,
but it is the skill that will help you the most in the long run .
