SQL, or Structured Query Language, is a programming language used to manage and manipulate relational databases. SQL is a popular language for managing data and has become an essential skill for data analysts, data scientists, and software developers.
SQL allows users to create, access, and manipulate large amounts of data stored in relational databases. It provides a straightforward way to retrieve and modify data, making it a powerful tool for managing data.
SQL is used in a wide range of industries, including finance, healthcare, and e-commerce. It is commonly used to perform tasks such as querying databases, inserting new data, updating existing data, and deleting unwanted data.
Many different tracks are available for learning SQL, ranging from beginner to advanced levels. Some popular SQL training tracks include SQL for Data Analysis, SQL for Business Intelligence, and SQL for Database Administration.
Learning SQL can be valuable for anyone who works with data, regardless of their job title or industry. It can help users make more informed business decisions, identify trends in data, and improve data management processes.
In conclusion, SQL is a powerful programming language used for managing and manipulating data stored in relational databases. It is an essential skill for anyone who works with data, and many different tracks are available for learning SQL at various skill levels.
Let's understand the difference between Database and File System.
Databases are collections of organized and structured data, while file systems are collections of unstructured files. Databases are designed to efficiently manage and manipulate large amounts of data, while file systems are better suited for storing and organizing individual files. Databases can also enforce data integrity constraints and support complex data queries, while file systems do not. Overall, databases are more powerful and flexible than file systems for managing and manipulating data.
Searching time in the File system is more compared to databases.
Memory utilization is more in the file system.
Concurrent access is possible in databases, but no such protocols exist in the file system.
No Role-based access in FS
No constraints for redundancy in FS.
Basic SQL Commands
SELECT: SELECT column_name(s) FROM table_name;
INSERT: INSERT INTO table_name (column1, column2) VALUES (value1, value2);
UPDATE: UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;
DELETE: DELETE FROM table_name WHERE condition;
CREATE: CREATE TABLE table_name (column1 datatype, column2 datatype);
ALTER: ALTER TABLE table_name ADD column_name datatype;
DROP: DROP TABLE table_name;
JOIN: SELECT * FROM table1 INNER JOIN table2 ON table1.column_name = table2.column_name;
GROUP BY: SELECT column1, COUNT(column2) FROM table_name GROUP BY column1;
ORDER BY: SELECT * FROM table_name ORDER BY column_name ASC/DESC;
Resources to learn SQL:
There are plenty of places to learn SQL from and that too for absolutely free, check some of them from the list below:
Codeacademy
W3Schools
SQLbolt
Khan Academy
SQLZOO