Gain insights into fundamental database concepts, relational databases, and entity-relationship diagrams. Learn about normalization techniques and basics of SQL to enhance database efficiency.

Databases are universal - they underlie the technology you use every day. They're a crucial component of everything from telecommunications systems, banking systems, and video games to just about any other software system that maintains some amount of persistent data.

In this course, you'll learn about the fundamental concepts of databases, why and when they're used, what relational databases are, and entity-relationship diagrams. You will also be exposed to techniques like normalization that help to increase the efficiency of databases. You'll wrap up with a look at the basics of Structured Query Language (SQL). 

After completing this course, you will be able to move onto more advanced courses involving database systems and SQL.

Database Design Fundamentals for Software Engineers

# LEFT JOIN 

The **LEFT JOIN** keyword returns all records from the left table (table1), and the matched records from the right table (table2). The result is `NULL` from the right side if there is no match.

## Syntax

```sql
SELECT table1.column1, table2.column2...

FROM table1

LEFT JOIN table2

ON table1.common_field = table2.common_field;
```

>Note: In some databases, LEFT JOIN is called LEFT OUTER JOIN.

## Example

We want to select all customers and any orders they might have placed:






In this lesson, we will discuss the LEFT JOIN keyword.

Introduction

Fundamental Concepts

Data Modeling

Entity-Relationship Data Model

The Relational Data Model

Functional Dependencies

Normalization

Structured Query Language

Conclusion

LEFT JOIN

LEFT JOIN