For an instructor lead, in-depth look at learning SQL click below.
Welcome to the exciting world of SQL! SQL, or Structured Query Language, is a language designed to allow both technical and non-technical users query, manipulate, and transform data from a relational database. And due to its simplicity, SQL databases provide safe and scalable storage for millions of websites and mobile applications. Let’s dive in!
What is SQL?
SQL stands for Structured Query Language. SQL lets you access and manipulate databases. SQL is an ANSI (American National Standards Institute) standard language, but there are many different versions of the SQL language, with different syntax and capabilities, based on the particular database management system (DBMS) you are using.
Where is SQL used?
SQL has a variety of applications and is used in many settings. Here are a few examples:
- Running complex queries against a database
- Creating and modifying database schemas
- Adding, updating, and deleting rows of data
- Retrieving subsets of information within a database for analytics and reporting
The Basic SQL Commands
Learning SQL involves understanding its basic commands, which include SELECT, INSERT, UPDATE, DELETE, and CREATE. Here are a few examples:
1. The SELECT Statement
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-- SELECT statement is used to fetch data from a database. -- Here is the SQL command to select all employees from an Employee table: SELECT * FROM Employees; |
2. The INSERT Statement
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-- INSERT statement is used to add new data into a database. -- Here is the SQL command to insert a new employee into an Employee table: INSERT INTO Employees (EmployeeName, EmployeeEmail) VALUES ('John Doe', <a href="mailto:'johndoe@example.com'" >'johndoe@example.com'</a>); |
3. The UPDATE Statement
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-- UPDATE statement is used to update existing data within a database. -- Here is the SQL command to update an employee's email in the Employee table: UPDATE Employees SET EmployeeEmail = <a href="mailto:'johnnydoe@example.com'" >'johnnydoe@example.com'</a> WHERE EmployeeName = 'John Doe'; |
4. The DELETE Statement
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-- DELETE statement is used to delete existing data within a database. -- Here is the SQL command to delete an employee from the Employee table: DELETE FROM Employees WHERE EmployeeName = 'John Doe'; |
5. The CREATE Statement
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-- CREATE DATABASE statement is used to create a new database in SQL. -- Here is the SQL command to create a new database called TestDB: CREATE DATABASE TestDB; |
This provides a simple introduction into SQL. As you can see, SQL commands allow you to perform a wide range of tasks and actions on your database. With practice, anyone can learn and master SQL to manipulate and analyze data effectively. Happy querying!