Explore BrainMass

Draw an E-R Diagram

Draw an E-R diagram with all appropriate notation for the following situation. In a particular fruit-growing region there are a number of orchards. Each ORCHARD is identified by its LOCATION. In general, each orchard contains a large number of trees (assume that an orchard must contain at least one tree). A TREE entity has the attributes NUMBER (which is a serial number) and YEAR PLANTED. Each tree is a member of a single SPECIES (for example, apple, peach, and plum are species). A species is identified by a SPECIES NAME. Each species bears one or more varieties. For example, with grafted branches, an apple tree might bear two varieties: Yellow Delicious, and Jonathon. Each VARIETY is identified by a VARIETY NAME. Each variety is borne by exactly one species (thus for example, a Yellow Delicious apple can only be borne by an apple tree.). From the previous discussion, we can infer that each tree has one or more varieties. At a given time, a particular species may not have any trees as members, or have one or more trees. Similarly, a given variety may or may not be represented by trees at a given time.

© BrainMass Inc. brainmass.com July 22, 2018, 4:39 pm ad1c9bdddf

Solution Summary

This Solution contains an Orchard E-R Diagram graphic.