How to insert multiple rows into an Order table? - sql

Question

So I set up a simple database and I am at the point where I am trying to test that it is working correctly. I am trying to figure out how I get multiple entries into an Order table. I need to have an order# and be able to order multiple items and use multiple shippers and such. I just can't seem to figure out a way to get the data into my DB properly.
Below is how I have my DB set up. Could someone please explain to me how to get the my test data into the DB.
Here are the reference tables:
CREATE TABLE Product_Table (
ProductID INT NOT NULL,
Product_Name char(50) NOT NULL,
Product_Cost number(9,2) NOT NULL,
Product_In_Stock INT NOT NULL,
CONSTRAINT Products_PK PRIMARY KEY (ProductID)
);
CREATE TABLE Payment_Terms_Table (
PayTermNum INT NOT NULL,
Payment_Time_Frame CHAR(20) NOT NULL,
CONSTRAINT Payment_Terms_PK PRIMARY KEY (PayTermNum)
);
CREATE TABLE Shipper_Table (
ShipperNum INT NOT NULL,
Shipper_Name CHAR(50) NOT NULL,
Shipper_Phone CHAR(22) NULL,
CONSTRAINT ShipperNum_PK PRIMARY KEY (ShipperNum)
);
CREATE TABLE Supplier_Table (
SupplierID INT NOT NULL,
Supplier_Name CHAR(50) NOT NULL,
Sup_Address CHAR(50) NOT NULL,
Sup_City CHAR(20) NOT NULL,
Sup_State CHAR(20) NOT NULL,
Sup_Zip CHAR(9) NOT NULL,
Sup_Phone CHAR(22) NULL,
ShipperNum INT NOT NULL,
PayTermNum INT NOT NULL,
CONSTRAINT Supplier_PK PRIMARY KEY (SupplierID),
CONSTRAINT ShipperNum_Relationship FOREIGN KEY (ShipperNum)
REFERENCES Shipper_Table (ShipperNum),
CONSTRAINT PayTermNum_Relationship FOREIGN KEY (PayTermNum)
REFERENCES Payment_Terms_Table (PayTermNum)
);
Here is my Order table:
CREATE TABLE Order_Table (
OrderID INT NOT NULL,
ProductID INT NOT NULL,
SupplierID INT NOT NULL,
Wholesale_Price NUMBER (9,2) NOT NULL,
Units_Ordered INT NOT NULL,
Order_Date DATE DEFAULT SYSDATE NOT NULL,
Order_Received DATE NULL,
CONSTRAINT Order_PK PRIMARY KEY (OrderID),
CONSTRAINT ProductID_Relationship FOREIGN KEY (ProductID)
REFERENCES Product_Table (ProductID),
CONSTRAINT SupplierID_Relationship FOREIGN KEY (SupplierID)
REFERENCES Supplier_Table (SupplierID)
);

Answer 1

Your problem is that you have a defined one table to hold Orders, so you can have only one Item per Order. Normally we handle this scenario by having two tables: a Header with the information for the whole Order and a Line table for each ordered Item.
CREATE TABLE Order_Header (
OrderID INT NOT NULL,
Order_Date DATE DEFAULT SYSDATE NOT NULL,
Order_Received DATE NULL,
CONSTRAINT Order_PK PRIMARY KEY (OrderID)
)
/
CREATE TABLE Order_Line (
OrderID INT NOT NULL,
LineNo INT NOT NULL,
ProductID INT NOT NULL,
SupplierID INT NOT NULL,
Wholesale_Price NUMBER (9,2) NOT NULL,
Units_Ordered INT NOT NULL,
CONSTRAINT Order_Line_PK PRIMARY KEY (OrderID, LineNo),
CONSTRAINT Order_Line_Header_FK FOREIGN KEY (OrderID)
REFERENCES Order_Header (OrderID)
CONSTRAINT ProductID_Relationship FOREIGN KEY (ProductID)
REFERENCES Product_Table (ProductID),
CONSTRAINT SupplierID_Relationship FOREIGN KEY (SupplierID)
REFERENCES Supplier_Table (SupplierID)
)
/
I have declared a composite primary key because it is easier to understand what's happening.
Now that you have two tables you can easily create orders with more than one line.
On the subject of normal practice, an Order should have a CUSTOMER. That would be an attribute of ORDER_HEADER. Also you have a SHIPPER table but don't use it. Again that would probably be an attribute of ORDER_HEADER.
Also your naming convention is ugly. There's no need to include _TABLE: just name the objects for teh things they represent. Likewise your foreign key needs are opaque; it doesn't matter so much in this toy example but in a real database you will find it helpful to specify the child and parent tables in the FK names.