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I am reverse engineering an database to create an database ER diagram in Visio. When I display the table in Visio, on the left hand side of the entity diagram, I see symbols next to the column names that I do not know what they mean. Symbols such as, U1, U2, l1, l2, l5...etc. Others symbols such as PK (primary key) and FK (foreign key) are also shown in the same area, but those obviously make sense to me.
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U1 = Unique Index 1.....
You read the diagrams first from left to right and then from right to left. In the case of the name-address relationship in following figure, you read the relationships as follows: names can be associated with zero or exactly one address; addresses can be associated with zero, one, or many names.
An entity relationship diagram (ERD) illustrates how different entities (such as customers and products) relate to each other in a database. Here are the the three primary parts of an ERD: Entities: The tables in your database. Entities are nouns.
These are other types of indexes.
U1 = Unique Index 1..... I1 = Index 1......
Here are examples in SQL Server http://msdn.microsoft.com/en-us/library/ms188783.aspx
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