It helps me to make a relation entity model with barker notation of the following problem.

A company asks you. to design a database to conduct surveys on radio programming. What follows is the result of the survey carried out by the company's analysts. There is a set of radios, whose characteristics are known (which identifies them), a name, the frequency on which it transmits and the type of transmission (AM.FM).

Each radio broadcasts programs that are identified by a name and of which a genre is known (journalistic, sports, musical, cultural, varieties). Each program can be broadcast by different radios. It is important to note that each radio can carry out more than one broadcast of each program, recording for each broadcast the date, the start time, the duration and whether it is a repetition or not.

Sometimes, for a broadcast of a program, a survey is carried out in which the following data is recorded: the total number of respondents, the number of approvals, the number of rejections and the number of indifferences. Obviously, the company expects these amounts to close correctly.

The programs can also be summary programs in which case it is interesting to know from which other programs they take the notes. Each program is produced by a single consortium made up of one of the radio stations that broadcast it and a production company. Of the production companies their number is known. of the Federal Taxpayers Registry (RFC), a name and their telephone numbers. It is not allowed that two production companies can have the same name.

In each production company, people directly related to the programs work, whose identity card and name are known. These people can be Drivers, Operators or Producers. Production companies do not allow a person to work in more than one of them. It is interesting to register for each program, who are the drivers, operators and producers. The producers, in each program in which they work, can carry out journalistic or commercial production.

On the other hand, there are some drivers who have a preference for working with some operators. It is clear that all programs have at least one host, one producer and one operator, although they could have several people for each role.