GROUP BY clause?Check if your source tables or nested queries have duplicated rows. You’ll need to repeat steps 3 and 4 for every table or query result that contains duplicate rows.
-- If the row_count is greater than 1,
-- you have duplicated rows in your results.
SELECT
< your_columns >,
COUNT(*) AS row_count
FROM
< your_table_or_upstream_query >
GROUP BY
< your_columns >
ORDER BY
row_count DESC;