Employee Runner-Up Salary Lookup

Medium

Your team is building a compensation analytics endpoint over an Employee table with columns (id, salary). You must return the second-highest distinct salary in the dataset. The output must be a one-column result named SecondHighestSalary. Important rules: Salaries with the same value count once for ranking. If fewer than two distinct salary values exist, return null (None in Pandas). Input row order has no semantic meaning. Submissions are supported in: SQL (SQLite 3.27.2) Python (Pandas)

Input

Employee:
| id | salary |
|----|--------|
| 1  | 100    |
| 2  | 200    |
| 3  | 300    |

Output

[{"SecondHighestSalary":200}]

Explanation

Distinct salaries are [300, 200, 100], so the second-highest value is 200.

Input

Employee:
| id | salary |
|----|--------|
| 1  | 500    |
| 2  | 500    |

Output

[{"SecondHighestSalary":null}]

Explanation

There is only one distinct salary value, so no second-highest value exists.

Input

Employee:
| id | salary |
|----|--------|
| 1  | -10    |
| 2  | -30    |
| 3  | -10    |
| 4  | -20    |

Output

[{"SecondHighestSalary":-20}]

Explanation

Distinct salaries are [-10, -20, -30] in descending order. The second value is -20.

Constraints

1 <= number of rows in Employee <= 100,000
Employee.id is unique
salary is a signed integer in the range [-2,147,483,648, 2,147,483,647]
Output must contain exactly one column: SecondHighestSalary
Use SQLite 3.27.2 behavior for SQL submissions
For Pandas, return a DataFrame with one row and one column named SecondHighestSalary