Solution – Daily Product Revenue¶ Let us review the Final Solution for our problem statement daily_product_revenue. Prepare tables Create tables Load the data into tables We need to project the fields which we are interested in. We need to have product_id as well as product_name as there can be products with same name and can …
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Sorting Data¶ Let us understand how to sort the data using SQL. We typically perform sorting as final step. Sorting can be done either by using one field or multiple fields. Sorting by multiple fields is also known as composite sorting. We can sort the data either in ascending order or descending order by using …
Performing Aggregations¶ Let us understand how to aggregate the data. We can perform global aggregations as well as aggregations by key. Global Aggregations Get total number of orders. Get revenue for a given order id. Get number of records with order_status either COMPLETED or CLOSED. Aggregations by key – using GROUP BY Get number of …
Joining Tables – Outer¶ Let us understand how to perform outer joins using SQL. There are 3 different types of outer joins. LEFT OUTER JOIN (default) – Get all the records from both the datasets which satisfies JOIN condition along with those records which are in the left side table but not in the right …
Joining Tables – Inner¶ Let us understand how to join data from multiple tables. We will primarily focus on ANSI style join (JOIN with ON). There are different types of joins. INNER JOIN – Get all the records from both the datasets which satisfies JOIN condition. OUTER JOIN – We will get into the details …
Selecting or Projecting Data¶ Let us understand different aspects of projecting data. We primarily using SELECT to project the data. We can project all columns using * or some columns using column names. We can provide aliases to a column or expression using AS in SELECT clause. DISTINCT can be used to get the distinct …
