How can I learn SQL all over again if I were to start over? During your early days of learning you find yourself always in a dilemma of where to start learning SQL, What resources best suites your learning journey, What is the correct way to learn SQL and it seems like you are in a state of confusion, right?
This is a comprehensive guide for beginners trying to set foot in the data industry. SQL(Structured Query Language) is a programming language used for manipulating relational databases
1. Define database(s)
- Define what a database is and the list out different types of databases(i.e relational and non relational databases)
- Install and set up a database management system on your local machine
2. Basics of SQL
- Define SQL and state features of SQL
- What are the common Data Types mostly used in SQL
- Understand basic syntax of SQL queries
3. Basic Commands in SQL
- Select statement It is used to retrieve data from tables e.g
select name, age from students
- Sorting and filtering data Using order by to sort data, where to filter data based on a condition and limit clause to specify number of to be returned by a query
- Aggregate functions Learn to use MAX, MIN, AVERAGE, COUNT, SUM
-
Group by and Having Clause
group data and understand how to filter grouped data4. Data manipulation
Insert
add new records to a tableupdate
Modify existing records in a table-
delete
remove records from a table in a database5. Database design
relationships
understand how tables are related via primary and foreign keys, and the different types of relationships(i.e one to one, one to many)-
Database normalisation
Define normalisation and the different types of normalisation6. Advaced SQL Queries
Subqueries
Writing a query inside another queryJoins
Combining one or more rows of data from multiple tables using joins i.e(inner join, left join, right join, cross join)-
Indexing
Define indexing and the importance of indexes7. SQL functions and procedures
Functions
What are functions and the inbuilt SQL functions-
Triggers and procedures
Define procedures and triggers, types of triggers and their applications8. Practice writing SQL
Hands on practice
Login to chatgpt and ask chatgpt to produce dummy data to insert to your database
Lastly, ask chatgpt to formulate questions to practice writing your SQL queriesJoin an online community
Join whatsapp, Linked in and SQL groups on social media.
Conclusion
By following this road map as beginner, you will build your skills in SQL. Ensure you have lots of practice so as to be proficient in SQL.
The above is the detailed content of SQL(Structured Query Language) Road Map for beginners. For more information, please follow other related articles on the PHP Chinese website!

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