CREATE TABLE Ref_Document_Types (
Document_Type_Code CHAR(15) NOT NULL,
Document_Type_Name VARCHAR(255) NOT NULL,
Document_Type_Description VARCHAR(255) NOT NULL,
PRIMARY KEY (Document_Type_Code)
)

CREATE TABLE Ref_Calendar (
Calendar_Date DATETIME NOT NULL,
Day_Number INTEGER,
PRIMARY KEY (Calendar_Date)
)

CREATE TABLE Ref_Locations (
Location_Code CHAR(15) NOT NULL,
Location_Name VARCHAR(255) NOT NULL,
Location_Description VARCHAR(255) NOT NULL,
PRIMARY KEY (Location_Code)
)

CREATE TABLE Roles (
Role_Code CHAR(15) NOT NULL,
Role_Name VARCHAR(255),
Role_Description VARCHAR(255),
PRIMARY KEY (Role_Code)
)

CREATE TABLE All_Documents (
Document_ID INTEGER NOT NULL,
Date_Stored DATETIME,
Document_Type_Code CHAR(15) NOT NULL,
Document_Name CHAR(255),
Document_Description CHAR(255),
Other_Details VARCHAR(255),
PRIMARY KEY (Document_ID),
FOREIGN KEY (Document_Type_Code) REFERENCES Ref_Document_Types (Document_Type_Code),
FOREIGN KEY (Date_Stored) REFERENCES Ref_Calendar (Calendar_Date)
)

CREATE TABLE Employees (
Employee_ID INTEGER NOT NULL,
Role_Code CHAR(15) NOT NULL,
Employee_Name VARCHAR(255),
Gender_MFU CHAR(1) NOT NULL,
Date_of_Birth DATETIME NOT NULL,
Other_Details VARCHAR(255),
PRIMARY KEY (Employee_ID),
FOREIGN KEY (Role_Code) REFERENCES Roles (Role_Code)
)

CREATE TABLE Document_Locations (
Document_ID INTEGER NOT NULL,
Location_Code CHAR(15) NOT NULL,
Date_in_Location_From DATETIME NOT NULL,
Date_in_Locaton_To DATETIME,
PRIMARY KEY (Document_ID, Location_Code, Date_in_Location_From),
FOREIGN KEY (Location_Code) REFERENCES Ref_Locations (Location_Code),
FOREIGN KEY (Date_in_Location_From) REFERENCES Ref_Calendar (Calendar_Date),
FOREIGN KEY (Date_in_Locaton_To) REFERENCES Ref_Calendar (Calendar_Date),
FOREIGN KEY (Document_ID) REFERENCES All_Documents (Document_ID)
)

CREATE TABLE Documents_to_be_Destroyed (
Document_ID INTEGER NOT NULL,
Destruction_Authorised_by_Employee_ID INTEGER,
Destroyed_by_Employee_ID INTEGER,
Planned_Destruction_Date DATETIME,
Actual_Destruction_Date DATETIME,
Other_Details VARCHAR(255),
PRIMARY KEY (Document_ID),
FOREIGN KEY (Destroyed_by_Employee_ID) REFERENCES Employees (Employee_ID),
FOREIGN KEY (Destruction_Authorised_by_Employee_ID) REFERENCES Employees (Employee_ID),
FOREIGN KEY (Planned_Destruction_Date) REFERENCES Ref_Calendar (Calendar_Date),
FOREIGN KEY (Actual_Destruction_Date) REFERENCES Ref_Calendar (Calendar_Date),
FOREIGN KEY (Document_ID) REFERENCES All_Documents (Document_ID)
)
SELECT count(*) FROM All_documents WHERE document_type_code  =  "CV" OR document_type_code  =  "BK"
How many documents have document type code CV or BK?