You are asked to design an ER diagram for a system that keeps track of real...

   

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You are asked to design an ER diagram for a system that keeps track of real estate properties and listings. Below you can find the specifications given by a domain expert. We have a set of lots in an area. Each lot has an id that is unique and does not change over time. It also has an address and square footage that are stable and do not change over time. The lot may (or may not) have one building on it. (We do not allow lots to have more than one building.) The building can contain one or more dwellings. For example, a single-family house contains one dwelling, and a multi-family building contains multiple dwellings (i.e., multiple condo housing units). Each dwelling has a property type (single-family house, condo, coop, etc.), number of bedrooms, bathrooms, and square footage. In multi-family buildings, each dwelling (housing unit) will have a unit number assigned to it that is unique for that particular multi-family building. In single-family units, the unit number is not as useful, but we assume that the unit number exists and always gets a default value. We assume that the number of bedrooms, bathrooms and square footage remain unchanged over the life of the dwelling. Each dwelling has one or more owners. The owners buy the dwelling through a sales transaction. (Correspondingly, sell the unit when they transfer ownership to new owners.) We want to keep the historic ownership information, so the design should allow keeping the information for both the past and the current owners without confusion. The dwelling can be bought and sold, which transfers ownership from the sellers to You are asked to design an ER diagram for a system that keeps track of real estate properties and listings. Below you can find the specifications given by a domain expert. We have a set of lots in an area. Each lot has an id that is unique and does not change over time. It also has an address and square footage that are stable and do not change over time. The lot may (or may not) have one building on it. (We do not allow lots to have more than one building.) The building can contain one or more dwellings. For example, a single-family house contains one dwelling, and a multi-family building contains multiple dwellings (i.e., multiple condo housing units). Each dwelling has a property type (single-family house, condo, coop, etc.), number of bedrooms, bathrooms, and square footage. In multi-family buildings, each dwelling (housing unit) will have a unit number assigned to it that is unique for that particular multi-family building. In single-family units, the unit number is not as useful, but we assume that the unit number exists and always gets a default value. We assume that the number of bedrooms, bathrooms and square footage remain unchanged over the life of the dwelling. Each dwelling has one or more owners. The owners buy the dwelling through a sales transaction. (Correspondingly, sell the unit when they transfer ownership to new owners.) We want to keep the historic ownership information, so the design should allow keeping the information for both the past and the current owners without confusion. The dwelling can be bought and sold, which transfers ownership from the sellers to

Answer rating: 100% (QA)

Solution Here is the ER diagram for the real estate system entity Lot id integer PK address string s... View the full answer