**Chen Notation Diagramming Task**
**Objective:** Create a Chen Notation Entity-Relationship Diagram (ERD) based on the following information provided by the Temporary Employment Corporation (TEC). Only Chen Notation Diagrams will be accepted.
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**Description and Business Rules:**
1. **Candidates:**
- TEC maintains a file of candidates willing to work, which will be stored in a database.
- Each candidate may have a job history if they have worked before.
- Each job assignment results in a new job history record.
- Candidates have earned various qualifications, which can be shared by multiple candidates.
2. **Qualifications:**
- Qualifications are stored in the database. Multiple candidates can earn the same qualification, and one candidate can earn multiple qualifications.
3. **Courses:**
- TEC offers courses to help candidates earn qualifications. Each course develops a specific qualification, but not all qualifications have corresponding courses.
- Some courses have prerequisites, which are qualifications. A course can have multiple prerequisites.
4. **Companies and Job Openings:**
- TEC keeps a list of companies requesting temporary employees.
- Each job opening has an opening number, company name, required qualifications, start and end dates, and hourly pay. This information is stored in a database.
5. **Placements:**
- When a candidate meets the qualifications, they are placed in a job, and a placement record is created, which includes the opening number, candidate number, and total hours worked.
- An opening can be filled by many candidates, and a candidate can fill multiple openings.
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**Tasks:**
1. **Draw the Chen ERD for the Enterprise:**
- **Entities:** Identify entities such as Candidates, Qualifications, Courses, Companies, Job Openings, and Placements.
- **Attributes:** List all attributes for each entity, like Candidate ID, Qualification Name, Course Title, Company Name, etc.
- **Relationships:** Identify relationships between entities, such as Candidates have Qualifications, Companies have Job Openings, etc.
- **Cardinality:** Determine the cardinality for each relationship (e.g., one-to-many, many-to-many).
- **Resolve Relationships:** Resolve all 1:N and M:N relationships appropriately.
- **Primary and Foreign Keys:** Identify primary keys for each entity and map foreign keys based on cardinality.
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**Note:** Ensure the diagram represents all the given information accurately, maintaining a clear depiction of how the TEC system operates.
