INFOTECH Coding Question – Solved

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To approach the problem of creating a new table containing only the relevant information your boss needs from the existing Projects table, it's important to think in terms of data selection, filtering, and ordering.

The main objective here is to prepare a new view or table that excludes certain columns and includes only those that are meaningful to the stakeholder. Specifically, the internal_id and team_size columns must be removed since your boss considers these irrelevant, and the remaining columns—project_name, team_lead, and income—must be retained and presented in an organized fashion.

Here’s how you should think about the solution:

1. **Understanding the Data Structure and Requirements**
The original table, Projects, contains five columns, but only three are needed. Your output must have exactly these three columns:
- project_name
- team_lead
- income
The internal_id is still important in the context of sorting the records, but it should not appear in the final output. It is essentially a hidden ordering key.

2. **Data Projection (Selecting Specific Columns)**
The problem requires removing two columns and keeping the rest. This is analogous to a projection operation in database queries, where you specify exactly which columns to retrieve from the table. So, you focus on extracting only the relevant attributes (project_name, team_lead, income) for each project.

3. **Ordering the Result Based on an Excluded Column**
Even though internal_id is not part of the output, the final rows need to be sorted by internal_id in ascending order. This implies that while your boss does not want to see the internal_id, the order of rows must respect this hidden key. This means internally, the system should use internal_id to sort the data before presenting the filtered columns.

4. **Preserving the Integrity and Completeness of Data**
When you filter columns and sort by a column you don’t include in the output, it is crucial that you do not lose the connection between project_name, team_lead, income, and internal_id. Each row's data should stay correctly associated with the corresponding internal_id for correct ordering.

5. **Edge Cases and Validation**
Think about potential edge cases:
- What if the table is empty? The output should simply be empty, preserving the column structure requested.
- What if there are multiple projects with the same income or team_lead? Since sorting is strictly by internal_id, these duplicates do not affect ordering but might affect presentation.
- What if some columns contain NULL or missing data? Decide how to handle these scenarios (usually NULLs are allowed, but it depends on database constraints).

6. **Performance Considerations for Large Datasets**
If the Projects table is large, ensure that the sorting operation is efficient. Since internal_id presumably is a unique identifier and possibly indexed, sorting by it should be fast. Selecting only necessary columns reduces data load.

7. **How This Maps to SQL (Conceptual Understanding)**
Although the problem does not explicitly ask for SQL, it’s helpful to think of this task in terms of a SQL query to better understand the underlying operation. The equivalent conceptual steps are:
- SELECT project_name, team_lead, income
- FROM Projects
- ORDER BY internal_id ASC

8. **Result Format**
Your output table should have exactly three columns, and the rows sorted by the hidden key (internal_id). The column headers must be project_name, team_lead, and income, reflecting the filtered dataset your boss requested.

By focusing on these key points—filtering columns, preserving ordering by an excluded column, and maintaining data integrity—you can efficiently transform the original Projects table into the desired output. This approach can be generalized to any data transformation task where specific columns are to be removed or included and the order must be maintained according to another attribute.
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