anchor.diff:  
   let createT4SQL = """
   create table Test4 (
  -	id serial,
  -	age   integer,
  -	first	varchar(100),
  -	last   varchar(100),
  -	rate   float,
  +    id serial,
  +    age   integer,
  +    first	varchar(100),
  +    last   varchar(100),
  +    rate   float,
       happy  boolean,
       CONSTRAINT pk_proj PRIMARY KEY (id)
   )"""
  
positive.code:                                                 |> conn.ExecuteScalar |> ignore
  let createT1SQL = """
  create table Test1 (
  	id integer NOT NULL,
  	age   integer NOT NULL,
  	first	varchar(100) NOT NULL,
  	last   varchar(100) NOT NULL,
  	rate   float NOT NULL
  )"""
  
  type Test1 = { id : int ; age : int ; first : string ; last : string ; rate : float}
  
negative.code: 
  let createT2SQL = """
  create table Test2 (
      id serial,
      age   integer  NOT NULL,
      first	varchar(100) NOT NULL,
      last   varchar(100) NOT NULL,
      rate   float NOT NULL default 999.0
  )"""
  
  
  let createT3SQL = """
  create table Test3 (
      id serial,
      age   integer NOT NULL,
      first	varchar(100) NOT NULL,
      last   varchar(100),
      rate   float NOT NULL
  )"""
  
  type Test3 = { id : int ; age : int ; first : string ; last : string option ; rate : float}
  