You may want to use the date '9/9/9999' for the EndDate in the TeamPlayers table since its much easier to handle a date in the programming rather than NULL and it makes it easier to handle the BETWEEN function.

hi
I created my entities with the intention of not having to put much of my own energy into feeding them. For example, I have an entity designed to bring me customers for my business, and designated that it should feed itself on every commercial transaction that takes place anywhere. I did similar things for other entities, giving them an energy source other than myself. However, I haven't noticed much results from my entities.