在SQL Server 2016中，必须声明标量变量“ @AccessLevel”？

我需要编写一个这样的存储过程：我通过表中的值，编写这个存储过程，首先我需要检查数据Access和RoleId存在于数据库中; 如果没有，需要将其插入表中。

我写了这个：

ALTER PROCEDURE [dbo].[InsertAndUpdateAccessLevel]
    (@AccessLevel AS AccessLevel READONLY)
AS
BEGIN
    DECLARE @AC AccessLevel;
    SET @AC = @AccessLevel;

    IF NOT EXISTS (SELECT Id
                   FROM RoleAccess 
                   WHERE RoleAccess.RoleId = @AC.RoleId
                     AND RoleAccess.Access = @AC.Access)
        INSERT INTO RoleAccess (RoleId, Access, IsDelete)
            SELECT * FROM @AccessLevel
END

得到这些问题： Msg 137, Level 16, State 1, Procedure InsertAndUpdateAccessLevel, Line 8 [Batch Start Line 7] Must declare the scalar variable "@AccessLevel".

Msg 137, Level 16, State 1, Procedure InsertAndUpdateAccessLevel, Line 8 [Batch Start Line 7] Must declare the scalar variable "@AC".

Msg 137, Level 16, State 1, Procedure InsertAndUpdateAccessLevel, Line 15 [Batch Start Line 7] Must declare the scalar variable "@AC".

Msg 137, Level 16, State 1, Procedure InsertAndUpdateAccessLevel, Line 16 [Batch Start Line 7] Must declare the scalar variable "@AC".

我该如何解决？