43+ Design Entity Relationship Diagram Foreign Key Example Download Zip Pictures. There are two reasons to create a database diagram. • to illustrate how relationships between entities are foreign keys reference the primary keys in the.
Entity tables will often have a entities have attributes, which will later more or less become the fields.
Each instance becomes a record or a row in a table. The entity relationship diagram or erd is set to help and understand the correlation between the entity sets that are available in a database. Other tables of which it has a relationship with. For each attribute we have the in the diagram, we will underline the key attributes.