Coalesce null salaries to zero

SQL data engineering interview problem. Difficulty: beginner. Pattern: Missing Data. About 8 minutes. Free to practice.

A report is going to a manager who gets confused by empty cells. Some employees have no salary on file (NULL), and the report should show 0 for them instead of leaving the cell blank. Return every employee's name and salary. When the salary is NULL, show 0. Sort by name from A to Z.

Requirements

  • Return every employee, with no rows removed.
  • Replace a NULL salary with 0 using COALESCE.
  • The column must still be called salary, so give the COALESCE result that name with AS.
  • Sort by name from A to Z.

Constraints

  • The table is employees.
  • Return only these 2 columns, in this order: name, salary.
  • Each employee appears exactly once.

Examples

Input: employees name | salary Alice Chen | 120000 Max Reed | NULL Omar Ali | 105000 Output: name | salary Alice Chen | 120000 Max Reed | 0 Omar Ali | 105000 Why this passes: COALESCE replaces NULL with 0 without dropping the row.

Topics: lakebench, sql, coalesce, null.

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beginner

Coalesce null salaries to zero

Interview-style drill: Return each employee name with salary defaulted to 0 when NULL.

For every employee, return `name` and `salary` where NULL salary becomes 0 via COALESCE. Order by `name`.