SQL Tutorial: Ordering and filtering

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. --- We've seen how to limit the number of rows returned using TOP. Now, we'll learn more advanced filtering and sorting, using WHERE and ORDER BY. Tables comprise of rows and columns, and you will usually see your query results displayed in a tabular format. But we should bear in mind that queries return specific SETS of data that meet the conditions we specify , and that sets have no default order. There is no guarantee our query will return the results in the same order each time. However, we can make this happen using ORDER BY. To order our query results, we write ORDER BY below FROM, then list the columns we want to sort by. Here, we sort by year_intro, then the product_id column. Notice rows 4-6, and 9 -10, have the same values in the year_intro column, so the product_id column determines their final row position We can ORDER BY any column - including columns that do not appear in the SELECT part of the query. Here we add DESC after the year_intro column in the ORDER BY clause. This sorts the results in descending order. We can sort by multiple columns. On the left,the columns are first sorted by year_intro in descending order, and then channels in ascending order. Year_intro is listed first in the ORDER BY clause, so it takes precedence when sorting the rows. Then the channels column is sorted in ascending order, for each year. On the right, both columns are sorted in descending order. We can also order string or text fields. On the left we see name_alias sorted from A-Z, and from Z-A on the right. You won't usually want to return all the rows in your table. You will have specific information you need to extract. For this, you need to use the WHERE clause, which we place underneath the FROM section of the query. We use the WHERE