You want to create a view RecentOrders that always shows orders placed in the last 7 days from the Orders table with columns order_id, customer_id, and order_date. Which SQL statement correctly creates this view?
ACREATE VIEW RecentOrders AS SELECT order_id, customer_id, order_date FROM Orders WHERE order_date > CURRENT_DATE - INTERVAL '7 days';
BCREATE VIEW RecentOrders AS SELECT order_id, customer_id FROM Orders WHERE order_date > CURRENT_DATE - INTERVAL '7 days';
CCREATE VIEW RecentOrders AS SELECT * FROM Orders WHERE order_date > DATEADD(day, -7, GETDATE());
DCREATE VIEW RecentOrders AS SELECT order_id, customer_id FROM Orders WHERE order_date > SYSDATE - 7;
Step-by-Step Solution
Solution:
Step 1: Identify needed columns and date filter
The view should include order_id, customer_id, and order_date columns and filter orders from last 7 days.
Step 2: Check each option's correctness
CREATE VIEW RecentOrders AS SELECT order_id, customer_id FROM Orders WHERE order_date > CURRENT_DATE - INTERVAL '7 days'; misses order_date column, so it won't show the date. CREATE VIEW RecentOrders AS SELECT order_id, customer_id, order_date FROM Orders WHERE order_date > CURRENT_DATE - INTERVAL '7 days'; includes all needed columns and uses correct standard SQL interval syntax. CREATE VIEW RecentOrders AS SELECT * FROM Orders WHERE order_date > DATEADD(day, -7, GETDATE()); uses SQL Server syntax (DATEADD, GETDATE) which may not be standard. CREATE VIEW RecentOrders AS SELECT order_id, customer_id FROM Orders WHERE order_date > SYSDATE - 7; uses SYSDATE which is Oracle-specific and may not work in standard SQL.
Final Answer:
CREATE VIEW RecentOrders AS SELECT order_id, customer_id, order_date FROM Orders WHERE order_date > CURRENT_DATE - INTERVAL '7 days'; -> Option A
Quick Check:
Include needed columns and use standard interval syntax [OK]
Quick Trick:Include all needed columns and use standard date intervals [OK]
Common Mistakes:
MISTAKES
Omitting important columns in view
Using non-standard date functions
Forgetting to filter by date correctly
Master "Views" in SQL
9 interactive learning modes - each teaches the same concept differently
