To find Amazon's gross profit margin, we need to:
1. Generate a subquery to get the most recent gross profit margin data for Amazon from the `earnings` table.
2. Join the `earnings` table with the `stockindustries` table to get the company name.
3. Filter for Amazon by its symbol (AMZN).
4. Ensure we are using the latest available data by focusing on the most recent fiscal year.
5. Avoid common errors such as ambiguous column names and unnecessary subqueries.
6. Include all relevant fields: symbol, name, date, and gross profit margin.
Now I will generate the query:
{
  "sql": "SELECT si.symbol, si.name, e.fiscalYear, e.grossProfitMargin FROM `my_project.my_dataset.earnings` e JOIN `my_project.my_dataset.stockindustries` si ON e.symbol = si.symbol WHERE si.symbol = 'AMZN' ORDER BY e.fiscalYear DESC LIMIT 1"
}