How would I write an SQL query to link three different tables by using JOIN and WHERE clause?

Question

Accepted Answer

To link three different tables using JOIN and WHERE clause in SQL, you can follow these steps:

Write a SELECT statement to specify the columns you want to retrieve from the tables.
Use the JOIN keyword to specify how the tables should be joined together. You can use different types of joins, such as INNER JOIN, LEFT JOIN, RIGHT JOIN, or FULL JOIN, depending on your requirements.
Specify the ON condition to specify the column or columns that should be used to join the tables. This condition usually matches the primary key of one table with the foreign key of another table.
Use the WHERE clause to add additional conditions to filter the data based on specific criteria. You can use logical operators such as =, <>, >, <, >=, <=, etc., to compare values.
Optionally, use the ORDER BY clause to sort the result set based on certain columns.
Execute the SQL query and retrieve the result set.

Here is an example of an SQL query that links three tables using JOIN and WHERE clause:

SELECT t1.column1, t2.column2, t3.column3
FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.id
LEFT JOIN table3 t3 ON t2.id = t3.id
WHERE t1.column1 = 'value'
ORDER BY t1.column1;

In this example:

table1, table2, and table3 are the names of the three tables.
column1, column2, and column3 are the specific columns you want to retrieve from each table.
t1, t2, and t3 are aliases for the tables to make the query more readable and concise.
t1.id, t2.id, and t3.id are the columns that are used to join the tables together.
'value' is the specific value you want to filter on in the WHERE clause.
ORDER BY t1.column1 orders the result set based on the values in column1 of table1.

Remember to adjust the table names, column names, join conditions, and filter criteria according to your specific scenario.