Structured Query Language
SQL is the standard programming language used for database management and data manipulation. It is a powerful tool for performing data querying, insertion, updating and deletion operations.
The history of SQL and important turning points in the database world
Edgar F. Codd introduced the relational database model at IBM and laid the foundation for SQL.
Oracle (formerly Relational Software Inc.) launched the first commercial SQL database.
SQL was standardized by ANSI (American National Standards Institute).
Object-relational features, regular expressions and array types were added.
JSON support and row pattern recognition features were added to meet modern data needs.
Discover the powerful features of SQL and learn how to use it in database management
You can easily query the data you want from the database with complex queries and filter it.
select * from calisanlar where maas > 50000 order by maas desc;
select * from calisanlar where maas > 50000 order by maas asc;
select * from calisanlar where maas > 50000 order by maas asc limit 10;
You can enter data by using the INSERT command to add new records to the database.
insert into urunler (name, price, category) values ('Laptop', 15000, 'Electronic');
You can make data changes by using the UPDATE command to update existing records.
update calisanlar set maas = maas * 1.1 where department = 'IT';
You can perform bulk calculations and analyses by grouping data with GROUP BY.
select department, count(*) from calisanlar group by department having count(*) > 5;
You can create relational queries by fetching data from multiple tables with JOIN operations.
select c.name, d.department_name from calisanlar c join departments d on c.dept_id = d.id;
You can perform mathematical operations, date calculations and text manipulation with built-in functions.
select upper(name), year(birth_date), round(salary, 2) from employees;
Compare different database management systems that support SQL
Open Source RDBMS
select * from users limit 10 offset 20;
Advanced Open Source RDBMS
select data->>'name' from json_table where data @> '{"age": 25}';
Corporate RDBMS
select employee_id, rownum from employees where rownum <= 10;
Microsoft RDBMS
select top 10 * from Customers order by CustomerID;
select * from Customers where CustomerID = 1;
select * from Customers where CustomerID = 1 and CustomerName = 'John Doe';
Lightweight File-based DB
create table users (id integer primary key, name text);
MySQL Fork
select * from products where match(description) against('laptop');
Practice with SQL projects at different difficulty levels
Simple e-commerce database design with product, category, order and customer tables.
Advanced SQL queries for book borrowing, member management and inventory tracking.
Advanced SQL for complex financial calculations, portfolio analysis and risk assessment.
Database design for patient records, appointment management and medical history tracking.
Optimized SQL queries for big data analysis, user interactions and trend analysis.
SQL database for inventory management, supplier relationships and inventory reporting.
Career opportunities and required skills for SQL