I need to make schedule for Instructor include

day,time,date time,courses,classes(lab or class room),instructor


so that i designed my database as following

my relations as following

Instructor with courses many to many

class with instructor many to many

Relation between class and instructor many to many because

instructor can teach in more classroom and class room can have

more instructor






Code:
CREATE TABLE [dbo].[Courses](

    [CourseID] [int] IDENTITY(1,1) NOT NULL,

    [CourseName] [nvarchar](50) NOT NULL,

 CONSTRAINT [PK_dbo.Courses] PRIMARY KEY CLUSTERED

(

    [CourseID] ASC

)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]

) ON [PRIMARY]

 

CREATE TABLE [dbo].[Class](

    [ClassID] [int] IDENTITY(1,1) NOT NULL,

    [ClassName] [nvarchar](50) NOT NULL,

 CONSTRAINT [PK_dbo.Class] PRIMARY KEY CLUSTERED

(

    [ClassID] ASC

)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]

) ON [PRIMARY]

 

CREATE TABLE [dbo].[Instructor](

    [InstructorID] [int] IDENTITY(1,1) NOT NULL,

    [IstructorName] [nvarchar](50) NOT NULL,

 CONSTRAINT [PK_dbo.Instructor] PRIMARY KEY CLUSTERED

(

    [InstructorID] ASC

)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]

) ON [PRIMARY]

 

CREATE TABLE [dbo].[InstructorCourses](

    [CourseID] [int] NOT NULL,

    [InstructorID] [int] NOT NULL,

    [fromtime] [nvarchar](50) NULL,

    [totime] [nvarchar](50)  NULL,

    [day] [nvarchar](50) NULL,

 CONSTRAINT [PK_dbo.InstructorCourses] PRIMARY KEY CLUSTERED

(

    [CourseID] ASC,

    [InstructorID] ASC

)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]

) ON [PRIMARY]

CREATE TABLE [dbo].[Instructor_Class](

    [ClassID] [int] NOT NULL,

    [InstructorID] [int] NOT NULL,

 CONSTRAINT [PK_dbo.Instructor_Class] PRIMARY KEY CLUSTERED

(

    [ClassID] ASC,

    [InstructorID] ASC

)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]

) ON [PRIMARY]
To make schedule for instructor i make relation between Instructor

table and Courses table many to many and generate third table

InstructorCourses table have InstructorID and CourseID

But
How to add ClassID to table InstructorCourses although Class table have relation many to many with table Instructor