Added module 7

courses/course_postgres_mastery/exercises/exercises_module_7.sql

@@ -0,0 +1,42 @@
+/*
+Exercises from the PostgreSQL Mastery course
+Module 7
+*/
+
+/* 49-01 */
+
+SELECT
+c.customer_id,
+c.first_name,
+c.last_name,
+c.email,
+s.order_id,
+s.order_date
+FROM customer c
+JOIN LATERAL (
+	SELECT co.*
+	FROM cust_order co
+	WHERE co.customer_id = c.customer_id
+	ORDER BY co.order_date ASC
+	FETCH FIRST 3 ROWS ONLY
+) s ON TRUE
+ORDER BY c.customer_id ASC;
+
+/* 51-01 */
+
+SELECT
+c.customer_id,
+c.first_name,
+c.last_name,
+c.email,
+s.order_id,
+s.order_date
+FROM customer c
+LEFT JOIN LATERAL (
+	SELECT co.*
+	FROM cust_order co
+	WHERE co.customer_id = c.customer_id
+	ORDER BY co.order_date ASC
+	FETCH FIRST 3 ROWS ONLY
+) s ON TRUE
+ORDER BY c.customer_id ASC;