SQL Tutorial: WHERE the wild things are

Want to learn more? Take the full course at https://learn.datacamp.com/courses/introduction-to-sql-serverat your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- You might need to apply more than one WHERE condition to your query. With AND, OR, and the correct use of parentheses, we can write queries to meet requirements and really impress our colleagues. On the left hand, the query returns records from the songlist table where the artist is AC/DC, giving us 29 rows in total. On the right-hand side, we add a further condition using `AND` after the WHERE clause, limiting records to those released prior to 1980. This reduces the number of rows that are returned to 9. Here's another example. By adding an additional AND statement, we reduce the number of rows returned from 3, to 1. Can you guess what this query might return? That's right - it will retrieve songs released in 1994. What about now? That's right, it also returns any song released after 2000. Using OR, we specify an alternate condition, and if a record meets either of the conditions, it is returned. Let's try another example. The top query returns Green Day songs from 1994 - a total of 3 rows. The middle query returns Green Days songs released after the year 2000. This also returns 3 rows. Now, if I ask for songs by Green Day, released in 1994 OR after 2000, how many rows will I retrieve? Six? Let's see the results... Whoa. That's not good. We've got more than 6 rows. Why do you think this happened? Let's figure this out. We asked for songs by Green Day, released in 1994 or after 2000. But, actually, we specified 2 completely different sets. The OR keyword specifies a different condition. So we actually asked for either songs by Green Day and released in 1994. OR any song, by any artist, released after 2000. So how do we fix this? By wrapping parentheses around the 2 release_year clauses, we make it clearer that we want songs by Gr