For an instructor lead, in-depth look at learning SQL click below.
Welcome to our beginner’s guide to SQL database management! SQL, also known as Structured Query Language, is an indispensable tool that is used to communicate with and manipulate databases. If you’re interested in managing data more efficiently, or if you’re just beginning your journey with databases, learning SQL will open doors to powerful data analysis and manipulation techniques.
What is SQL?
SQL is a standard language for managing data held in a Relational Database Management System (RDBMS), or for processing data in a stream management system. It includes operations for inserting, querying, updating, and deleting database records.
SQL Basics
Learning SQL is akin to learning a new language, a language that communicates with databases. The basic structure of an SQL command includes a statement which can be broken down into a select clause, from clause, where clause, group by clause, and order by clause.
Creating a Table
Let’s start with a simple example. Suppose we want to create a table called ‘Employee’. Here’s how we do it:
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CREATE TABLE Employee( ID INT PRIMARY KEY, name VARCHAR (20), birth_date DATE, job_title VARCHAR (20), salary INT ); |
In this example, ‘Employee’ is our table name. ‘ID’, ‘name’, ‘birth_date’, ‘job_title’ and ‘salary’ are columns in our table. Their data types are set alongside. ‘ID’ is set as the PRIMARY KEY, which means that each row of data can be uniquely identified by it.
Inserting Values
Now that we’ve created a table, let’s insert some data.
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INSERT INTO Employee(ID, name, birth_date, job_title, salary) VALUES (1, 'John Doe', '1980-04-12', 'Manager', 7000); |
This example introduces the INSERT INTO statement. This command allows us to insert new data into our table. We specify the column names after ‘INSERT INTO table_name’ and then provide the corresponding values after the VALUES keyword.
Reading Data
A crucial part of SQL management is being able to read your data. The ‘SELECT’ statement allows you to do this:
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SELECT * FROM Employee; |
This command selects all columns (*) from the ‘Employee’ table.
Conclusion
That’s a quick look at SQL database management for beginners. There is much more to learn including updating data, deleting data, and querying complex data structures.
This guide should have given you a clear understanding of what SQL is and might have just scratched the surface of how powerful SQL can be when it comes to managing databases. Happy learning!