IBM DB2 Aggregated Query

IBM DB2 is a relational Database management system that supports multiple aggregate queries. The following are some common types of aggregation queries and corresponding examples: 1. COUNT: Counts the number of non null values in a column. Example: Calculate how many customers are in a table named 'Customers': SELECT COUNT(*) FROM Customers; 2. SUM: Calculate the total value of a column. Example: Calculate the total amount of orders in the table named "Orders": SELECT SUM(OrderAmount) FROM Orders; 3. AVG: Calculate the average value of a column's values. Example: Calculate the average price of products in a table named 'Products': SELECT AVG(Price) FROM Products; 4. MAX: Find the maximum value in a column. Example: Find the oldest employee in the table named 'Employees': SELECT MAX(Age) FROM Employees; 5. MIN: Find the minimum value in a column. Example: Find the lowest priced product in the table named 'Products': SELECT MIN(Price) FROM Products; 6. GROUP BY: Group data by a certain column and execute aggregation functions within each group. Example: Find the total order amount for each customer in the table named "Orders": SELECT CustomerId, SUM(OrderAmount) FROM Orders GROUP BY CustomerId; 7. HAVING: Used together with GROUP BY to filter the results after grouping. Example: Find customers with a total order amount greater than 1000 in the table named "Orders": SELECT CustomerId, SUM(OrderAmount) FROM Orders GROUP BY CustomerId HAVING SUM(OrderAmount) > 1000; It should be noted that the above are only some common examples of aggregation queries. In fact, IBM DB2 also provides more aggregation functions and operations. For specific usage methods, please refer to IBM DB2's official documentation or related learning materials. At the same time, in practical use, it is also necessary to write corresponding query statements based on specific table structures and data.