Thank you Stephen and r937,
I am slowly beginning to understand.
I still have some questions in my mind about the key. Somewhere in phpMyAdmin, I read where it should be called "primary, and only primary". I tried this morning to find where I saw this, but I can't find it again.
Is it absolutely necessary for me to have a field with a unique value? If so why? Is it something MySql needs? I can't see where I, for my own use, need a unique value in any field.
If I need one, I can easily do as r937 mentioned about adding a number (1-4) to the date, but then do I need to do something else to indicate this is the primary key?
Where does one learn the finer details about this. Is there a on-line reference, or a book suitable for beginners?
One last question. If I ever need it, where under the structure tab do I find the way to auto-increment? I have spent hours trying to find this. The only reference I see to auto-increment is when you are going to move or copy a table.
Thanks again for you input on this.