-- You should determine which are the most fitting
-- data types and sizes for all your table columns
-- depending on your business context characteristics.

-- As one would expect, you are free to make use of
-- your preferred (or required) naming conventions.

CREATE TABLE Person (
    PersonId        INT      NOT NULL,
    FirstName       CHAR(30) NOT NULL,
    LastName        CHAR(30) NOT NULL,
    GenderCode      CHAR(3)  NOT NULL,
    BirthDate       DATE     NOT NULL,
    CreatedDateTime DATETIME NOT NULL,
    --
    CONSTRAINT Person_PK PRIMARY KEY (PersonId),
    CONSTRAINT Person_AK UNIQUE      (
        FirstName,
        LastName,
        GenderCode,
        BirthDate
    )
);

CREATE TABLE Survey (
    SurveyNumber    INT       NOT NULL,
    Description     CHAR(255) NOT NULL,
    CreatedDateTime DATETIME  NOT NULL,
    --
    CONSTRAINT Survey_PK PRIMARY KEY (SurveyNumber),
    CONSTRAINT Survey_AK UNIQUE      (Description)
);

CREATE TABLE PersonSurvey (
    PersonId           INT      NOT NULL,
    SurveyNumber       INT      NOT NULL,
    RegisteredDateTime DATETIME NOT NULL,
    --
    CONSTRAINT PersonSurvey_PK         PRIMARY KEY (PersonId, SurveyNumber),
    CONSTRAINT PersonSurveyToPerson_FK FOREIGN KEY (PersonId)
        REFERENCES Person (PersonId),
    CONSTRAINT PersonSurveyToSurvey_FK FOREIGN KEY (SurveyNumber)
        REFERENCES Survey (SurveyNumber)
);

CREATE TABLE Question (
    QuestionNumber  INT       NOT NULL,
    Wording         CHAR(255) NOT NULL,
    CreatedDateTime DATETIME  NOT NULL,
    --
    CONSTRAINT Question_PK PRIMARY KEY (QuestionNumber),
    CONSTRAINT Question_AK UNIQUE      (Wording)
);

CREATE TABLE SurveyQuestion (
    SurveyNumber       INT      NOT NULL,
    QuestionNumber     INT      NOT NULL,
    PresentationOrder  TINYINT  NOT NULL,
    IsMandatory        BIT      NOT NULL,
    IntegratedDateTime DATETIME NOT NULL,
    --
    CONSTRAINT SurveyQuestion_PK PRIMARY KEY (SurveyNumber, QuestionNumber),
    CONSTRAINT SurveyQuestion_AK UNIQUE      (
        QuestionNumber,
        SurveyNumber,
        PresentationOrder
    ),
    CONSTRAINT SurveyQuestionToSurvey_FK   FOREIGN KEY (SurveyNumber)
        REFERENCES Survey   (SurveyNumber),
    CONSTRAINT SurveyQuestionToQuestion_FK FOREIGN KEY (QuestionNumber)
        REFERENCES Question (QuestionNumber)
);

CREATE TABLE Response (
    SurveyNumber     INT      NOT NULL,
    QuestionNumber   INT      NOT NULL,
    PersonId         INT      NOT NULL,
    Content          TEXT     NOT NULL,
    ProvidedDateTime DATETIME NOT NULL,
    --
    CONSTRAINT Response_PK                 PRIMARY KEY (SurveyNumber, QuestionNumber, PersonId),
    CONSTRAINT ResponseToPersonSurvey_FK   FOREIGN KEY (PersonId, SurveyNumber)
        REFERENCES PersonSurvey   (PersonId, SurveyNumber),
    CONSTRAINT ResponseToSurveyQuestion_FK FOREIGN KEY (SurveyNumber, QuestionNumber)
        REFERENCES SurveyQuestion (SurveyNumber, QuestionNumber)
);