- Define SQL joins.
- Explain what SQL joins and how to use them.
- Use the different type of joins to display records.
- Shopping database example
An SQL JOIN clause is used to combine rows from two or more tables, based on a common field between them.
The most common type of join is: SQL INNER JOIN (simple join). An SQL INNER JOIN returns all rows from multiple tables where the join condition is met.
For the next 5 minutes, research SQL joins are
Now, turn & talk to your neighbor and discuss:
- At a high level, what are ORM's and how might they be useful?
- What is the importance of interfacing the server with the database?
#Different SQL JOINs Before we continue with examples, we will list the types of the different SQL JOINs you can use:
-INNER JOIN: Returns all rows when there is at least one match in BOTH tables -LEFT JOIN: Return all rows from the left table, and the matched rows from the right table -RIGHT JOIN: Return all rows from the right table, and the matched rows from the left table -FULL JOIN: Return all rows when there is a match in ONE of the tables
#SQL INNER JOIN Keyword The INNER JOIN keyword selects all rows from both tables as long as there is a match between the columns in both tables.
SQL INNER JOIN Syntax
SELECT column_name(s) FROM table1
INNER JOIN table2 ON table1.column_name=table2.column_name;
