HOW I STARTED SQL

Mugo Mwaniki Peter — Mon, 12 Aug 2024 09:35:18 +0000

What is SQL?

SQL (Structured Query Language) is a programming language designed for managing data in a relational database.

Why SQL?

SQL is the “meat and potatoes” of data analysis
It’s used for accessing, cleaning, and analyzing data that’s stored in databases
It’s semantically easy to understand and learn.
Because it can be used to access large amounts of data directly where it’s stored, analysts don’t have to copy data into other applications.
Compared to spreadsheet tools, data analysis done in SQL is easy to audit and replicate.

SELECT and FROM
SELECT indicates which columns you’d like to view, and FROM identifies the table that they are a part of.

SELECT Colname1,Colname2, Colname3...
FROM Tablename
If you want to select every column in a table, you can use * instead of the column names

The syntax in SQL is not case sensitive.
To format the way table names are printed using SELECT :

SELECT existingcolname AS wantedcolname,
FROM Tablename
Note : SELECT does NOT change any data in the database, it can only be used to fetch and print data.

LIMIT
LIMIT is used as a simple way to keep their queries from taking too long to return.
If the aim is to just look at data then first few are enough, no point in printing millions of rows because the query will take too long to give results.

SELECT Colname1,Colname2, Colname3...
FROM Tablename
LIMIT number

ORDER BY
ORDER BY is used when the result of a query are to be presented in an orderly fashion ( rating of products from highest to lowest ).

SELECT *
FROM tablename
ORDER BY colname
Orders the results in increasing order of column colname. The results are printed in ascending order by default, to print in descending order DESC has to be specified after each column in the clause.
Example: ORDER BY colname DESC
Ordering can also be done with multiple columns when the results need to be ordered but every category needs to be preserved.

SELECT *

FROM tablename

ORDER BY colname1, colname2

Comments
Comments are used to enhance the readability of code. When written between code lines the interpreter identifies them and does not execute them. Comments can span across one or multiple lines.
Single line comment : You can use — — (two dashes) to comment out everything to the right of them on a given line

SELECT * --This comment won't affect the way the code runs
FROM tablename

Multi line Comment : Comments across multiple lines use /* to begin the comment and */ to close.

SELECT * /* Here's a comment so long and descriptive that
it could only fit on multiple lines. Fortunately,
it, too, will not affect how this code runs.
*/
FROM tablename
WHERE
WHERE is used to filter the data with the help of a condition utilizing the comparison and logical operators.

SELECT Colname1,Colname2, Colname3...
FROM Tablename
WHERE condition
LIMIT number

DATA ANALYSIS TODAY

Mugo Mwaniki Peter — Sun, 04 Aug 2024 20:59:32 +0000

Embarking on a Data Analysis Journey with Lux ACADEMY Bootcamp

Just last week, I embarked on an exciting journey into the world of data analysis through Lux ACADEMY Bootcamp. As a professional with a passion for data, this bootcamp has been the perfect opportunity to deepen my knowledge and hone my skills. Although we are still in the early stages, the experience has already been incredibly enriching and engaging.

Introduction to Essential Tools

Our introduction to the field began with a focus on some of the most essential tools used in data analysis. We started with Google Colab, a powerful platform that facilitates collaborative work and provides a convenient way to write and execute Python code in a Jupyter notebook environment. This tool has been instrumental in our initial explorations of data manipulation and analysis.

Diving into Python for Analysis

As part of the curriculum, we've begun delving into Python, one of the most versatile and widely-used programming languages in data analysis. The course covered the basics and then moved on to more advanced topics, providing us with a solid foundation in using Python for various analytical tasks. From data cleaning and manipulation to creating visualizations, Python has proven to be an indispensable tool in our toolkit.

Exploring SQL for Database Management

In addition to Python, we've also started learning SQL (Structured Query Language), which is crucial for database management and data querying. Understanding how to efficiently retrieve and manage data from relational databases is a vital skill for any data analyst. The bootcamp has introduced us to fundamental SQL concepts, such as writing queries, filtering data, and aggregating results.

Ongoing Learning and Future Prospects

As we progress through the bootcamp, I am eager to continue expanding my knowledge and skills. The practical, hands-on approach of Lux CDEMY Bootcamp has been a fantastic way to apply what we're learning in real-world scenarios. While we're still in the early stages of our journey, the foundation we've built so far is already opening up new perspectives on data analysis.

I look forward to sharing more insights and experiences as we delve deeper into this fascinating field. Stay tuned for updates on our progress and the exciting projects we'll be undertaking!

DEV Community: Mugo Mwaniki Peter

HOW I STARTED SQL

DATA ANALYSIS TODAY