Question: UNION ALL Set Operator
Check your understanding of set operator UNION ALL.
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Question
Let’s say you’re part of a team that is managing a database, consisting of three tables, for your company. One of the table is Employees, which holds important details like names and salaries. The second table, Skills, contains information about the employee’s skills. The third table is named Projects, and it holds the information regarding the projects. The table structures are as follows:
Employees
EmpID | EmpName | Salary |
1 | Susan Lee | 50000.00 |
2 | Alexa Smith | 60000.00 |
3 | Sana Amberson | 45000.00 |
4 | Sarah Ronald | 47000.00 |
Skills
SkillID | EmpID | SkillName |
1 | 1 | C++ |
2 | 4 | Java |
3 | 1 | Python |
4 | 3 | Blender |
5 | NULL | Android |
Projects
ProjectID | EmpID | SkillID | ProjectName |
1 | 1 | 1 | Industrial Robot |
2 | 4 | 2 | Multiplatform GUI |
3 | 3 | 4 | 3D Simulation |
4 | 1 | 3 | Deep Learning Model |
5 | NULL | NULL | IOS App |
6 | 1 | NULL | Advanced Calculator |
7 | NULL | 5 | Android App |
8 | 1 | 1 | Industrial Robot |