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Q 1 . Consider the following set of simplified requirements for a LOL database that is used to keep track of the interactions between heroes,

Q1. Consider the following set of simplified requirements for a LOL database that is used to keep
track of the interactions between heroes, skills and equipments.
(i) Each hero has a unique hero ID, hero name, gender, and e-mail. Each hero must own several skills.
A hero may buy several equipments.
(ii) Each skill has a unique skill ID and a skill name. A skill may be owned by only one hero. A skill
may be supported by an equipment.
(iii) Each equipment has a unique equipment number, subject and content. An equipment may be
bought by several heroes. An equipment can be used to support several skills.
(a)(8%) Draw an ER (Entity-Relationship) diagram for this application. You need to clearly indicate
the cardinality ratio (1:1,1:N, or M:N) and participation constraints (total or partial) of each
relationship. (State clearly any additional assumptions you make)
(b)(5%) Map the ER schema into the corresponding relational database schema diagram. Specify all
the primary keys and foreign keys.
(iv) Suppose that Heroes can be distinguished as god-Heroes and black-Heroes. The database records
the number of like for God heroes and the number of unlike for black-Herores, respectively.
Please draw the EER model.
(c)(3%) Modify the ER schema in (a) according to the above requirements, using ER and Enhanced
ER concepts of specialization and generalization. You need to clearly indicate the disjointness and
completeness constraints. (State clearly any additional assumptions you make)Q1. Consider the following set of simplified requirements for a LOL database that is used to keep
track of the interactions between heroes, skills and equipments.
(i) Each hero has a unique hero ID, hero name, gender, and e-mail. Each hero must own several skills.
A hero may buy several equipments.
(ii) Each skill has a unique skill ID and a skill name. A skill may be owned by only one hero. A skill
may be supported by an equipment.
(iii) Each equipment has a unique equipment number, subject and content. An equipment may be
bought by several heroes. An equipment can be used to support several skills.
(a)(8%) Draw an ER (Entity-Relationship) diagram for this application. You need to clearly indicate
the cardinality ratio (1:1,1:N, or M:N) and participation constraints (total or partial) of each
relationship. (State clearly any additional assumptions you make)
(b)(5%) Map the ER schema into the corresponding relational database schema diagram. Specify all
the primary keys and foreign keys.
(iv) Suppose that Heroes can be distinguished as god-Heroes and black-Heroes. The database records
the number of "like" for God heroes and the number of "unlike" for black-Herores, respectively.
Please draw the EER model.
(c)(3%) Modify the ER schema in (a) according to the above requirements, using ER and Enhanced
ER concepts of specialization and generalization. You need to clearly indicate the disjointness and
completeness constraints. (State clearly any additional assumptions you make)
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