I don't see any error on your code, everything is well written and simple. Except trying putting PUBLIC on your Class displayer. If you encounter the same problem again try to rebuild your whole code and try to recompile the whole code. Even try restarting your personal computer.
Answer:
The corrected question is:
Write an SQL statement to display the WarehouseID, the sum of QuantityOnOrder and sum of QuantityOnHand, grouped by WarehouseID and QuantityOnOrder. Name the sum of QuantityOnOrder as TotalItemsOnOrder and the sum of QuantityOnHand as TotalItemsOnHand. Use only the INVENTORY table in your SQL statement.
Answer to this corrected question:
SELECT WarehouseID,
SUM(QuantityOnOrder) AS TotalItemsOnOrder,
SUM(QuantityOnHand) AS TotalItemsOnHand
FROM INVENTORY
GROUP BY WarehouseID, QuantityOnOrder;
According to the given question:
SELECT WarehouseID,
SUM(QuantityOnOrder) + SUM(QuantityOnHand) AS TotalItemsOnHand
FROM INVENTORY
GROUP BY WarehouseID, QuantityOnOrder;
Explanation:
- In the SQL statement SELECT statement is used to select the data from the table. Here the SELECT statement is used to select WarehouseID, Sum of the columns QuantityOnOrder and QuantityOnHand from INVENTORY table.
- The sum of QuantityOnOrder and QuantityOnHand columns are given the name of TotalItemsonHand (In case of the corrected question the sum of column QuantityOnOrder is named as TotalItemsOnOrder and the column QuantityOnHand is named as TotalItemsOnHand
) using Alias AS. Alias is the temporary name given to the columns or table to make them more readable.
- GROUP BY statement is used to arrange or "group" same data and is often use with aggregate functions like SUM function here. So the grouping here is done based on two columns WarehouseID and QuantityOnOrder.
- SUM function in this SQL statement is an aggregate function to calculate the sum of all value in the columns QuantityOnOrder and QuantityOnHand.
Answer:
The program keeps track of the size of the board in cards.size(). The sub class sets this by passing it into the constructor. After that, the subclass never cares about the size of the board, so it's not necessary to make it accessible with an abstract method. Any need for it is covered by cardIndexes method.
Explanation:
The differences between Elevens and Thirteens
The program keeps track of the size of the board in cards.size(). The sub class sets this by passing it into the constructor. After that, the subclass never cares about the size of the board, so it's not necessary to make it accessible with an abstract method. Any need for it is covered by cardIndexes method.
Answer:the answer is A
Explanation: develop a test to see what kind of circuits it takes to power a oven