Question

Due to your experience in designing the database for the "Legendary League" game, you have been asked to design the ER diagram for a bigger database to manage the events for the "Legendary League" eSports Oceanic Championship (OC). The requirements are as follows:

• Registered teams compete in the OC. Each team has a name, and a number of team members. A team also maintains a rank throughout the OC, reflecting how well it is doing in the championship.

• Team members are identified by a unique member id, their first name, and their surname. There are two types of team members: managers, and players. For each manager, their number of years of experience is tracked. Each player in a team has an in-game player name, and an assigned role in the team. A role can be one of "top", "mid", "jungle", "adc" or "support".

• A match is a contest between two teams. Teams get a final result, “win” or “lose”, for each match that they play in.

• Matches occur at a specified date and time. They also take place in uniquely named venues. In addition to names, venues have a location and a capacity. Only venues that are part of the OC need to be tracked.

• In a match, each player selects a single champion from a roster of pre-defined champions to play. Each champion may only be selected once in a match. A champion has a unique champion name, and also has a type (for example, “mage” or “support”).

• Additional performance statistics need to be recorded for each champion being used by a particular player in a particular match. The three statistics to be recorded are a count of the number of each of the "kills", "deaths" and "assists" that they achieve (for example, in a particular match, a particular player playing a particular champion might achieve 4 kills, 2 deaths, and 3 assists).

  According to the requirements above, give the ER diagram for the database using the UML class symbols (as used in the lecture notes and tutorials), making appropriate assumptions where necessary. You must represent entities, relationships and their attributes, and all applicable constraints in your diagram. Explain any constraints that cannot be expressed in the diagram.

this question (Due to your experience in designing the database for the "Legendary League" game) was as follow:

You are asked to design the ER diagram for a database to manage the data of an online multiplayer team game called "Legendary League". The requirements are:

• ● Players must register an account to play the game, and have a first name, last name, email address, and a chosen unique username.

• ● The game has a set of pre-defined characters available that a player can choose to play. Each character has a unique character name, can hold one or more items, has one or more abilities, and comes from a particular region.

• ● Each item has a unique name and type (where the type is one of "weapon", "shield" or "other").

• ● Each ability also has a unique name, and an associated rating. (For example, the ability "Fireblast" may

  currently be at rating 2 for a particular character.)

• ● Each player can use one or more characters, and go up in levels at different rates with each character.

  (For example, player "Joe" may currently be at level 1 with the character "Cindra", and at level 15 with

  character "Gargan").

• ● Each character comes from a single region, identified by the region's name. (For example, the

  character "Cindra" may be from the region "Zaund")

  According to the above description, construct an Entity Relationship (ER) diagram for the database. Clearly state any assumptions that you need to make. You must represent entities, relationships and their attributes, and all applicable constraints in your ER diagram. Explain any concepts that cannot be expressed in the ER diagram in the associated description.

• Your ER diagram must only use the UML class diagram notations from the lecture notes.

• You are encouraged to use LucidChart to complete your ER diagram. You can create a free student

  account at: http://www.lucidchart.com/

  Some common errors in ER diagrams:

• Every entity must have a primary key.

• The names of all relationships and entities must be unique.

• There are no foreign keys in ER diagrams. They come about as part of mapping an ER model into a

  relational schema.

Answer 1

Cardinality specifies how many instances of an entity relate to one instance of another entity. Ordinality is also closely linked to cardinality. While cardinality specifies the occurrences of a relationship, ordinality describes the relationship as either mandatory or optional. In other words, cardinality specifies the maximum number of relationships and ordinality specifies the absolute minimum number of relationships.

Steps involved :

1. identify entities
2. identify attributes for each entity
3. identify relations and involving entities
4. identify cardinality constraints

Legendary League Luser May 22, 2020 Item itemID Player itemName Charagter character D characterName firstname lastname email type items username choosenCharacter abilities region Ability abilityID abilityName rating Team Members memberID firstName name numPlayer rank members Champion championID lastName name type kills deaths assists Manager Match matchin HE managerID team firstName lastName experience teami team2 win matchDate matchTime match Venue OCVenue venueID location capacity