SQL Error Regarding Foreign Key Restraint - sqlite

Question

I am currently getting the following error when trying to add to one of my tables:
Error adding record: FOREIGN KEY constraint failed: (INSERT INTO Stock(StockID,ItemName,MinAmountRequired,AmountInStock,Order? (Yes/No),DataLastUpdated,OrderNumber,SupplierRefrence,PurchaseID`) VALUES (1,",0,0,",",0,0,0);)
Currently, This is how I have my tables set up:
Stock
CREATE TABLE Stock (
StockID INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
ItemName TEXT NOT NULL,
MinAmountRequired INTEGER NOT NULL,
AmountInStock INTEGER NOT NULL,
Order? (Yes/No) TEXT NOT NULL,
DataLastUpdated TEXT NOT NULL,
OrderNumber INTEGER NOT NULL UNIQUE,
SupplierReference INTEGER NOT NULL,
PurchaseID INTEGER NOT NULL UNIQUE,
FOREIGN KEY(PurchaseID) REFERENCES Purchase(PurchaseID),
FOREIGN KEY(OrderNumber) REFERENCES Orders(OrderNumber),
FOREIGN KEY(SupplierReference) REFERENCES Supplier(SupplierReference));
Orders
CREATE TABLE Orders (
OrderNumber INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
CustomerReferenceNumber INTEGER NOT NULL UNIQUE,
OrderDate TEXT NOT NULL,
ItemName TEXT NOT NULL UNIQUE);
Suppliers
CREATE TABLE Supplier (
SupplierReference INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
Name TEXT NOT NULL UNIQUE,
Address TEXT NOT NULL UNIQUE,
ContactNumber INTEGER NOT NULL UNIQUE);
Purchases
CREATE TABLE Purchase (
PurchaseID INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
Date TEXT NOT NULL,
AmountSpent REAL NOT NULL);

Answer 1

You have defined these foreign keys in table Stock:
FOREIGN KEY(PurchaseID) REFERENCES Purchase(PurchaseID),
FOREIGN KEY(OrderNumber) REFERENCES Orders(OrderNumber),
FOREIGN KEY(SupplierReference) REFERENCES Supplier(SupplierReference)
meaning that the values in columns PurchaseID, OrderNumber, SupplierReference need to reference values in columns of the tables Purchase, Orders and Supplier.
But you want to store 0 to all of these columns which I'm sure that is not the value of any of the referenced columns, since these referenced columns are defined as
PRIMARY KEY AUTOINCREMENT
and so their values are > 0.
Pass valid values that do exist in these 3 tables and the statement will execute succesfully.