text: CREATE TABLE Portfolio
  (
  	Id INTEGER PRIMARY KEY AUTOINCREMENT,
  	PortfolioName TEXT NOT NULL
  );
  
  CREATE TABLE PortfolioValuation
  (
  	Id INTEGER PRIMARY KEY AUTOINCREMENT,
  	PortfolioId INTEGER NOT NULL,
  	ValuationDate DATETIME NOT NULL,
  	Value REAL NOT NULL,
  	FOREIGN KEY(PortfolioId) REFERENCES Portfolio(Id)
  );
  
  CREATE TABLE HoldingValuation
  (
  	Id INTEGER PRIMARY KEY AUTOINCREMENT,
  	PortfolioId INTEGER NOT NULL,
  	ValuationDate DATETIME NOT NULL,
  	Symbol TEXT NOT NULL,
  	Value REAL NOT NULL,
  	FOREIGN KEY(PortfolioId) REFERENCES Portfolio(Id)
  );