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Check this query before I run it

Before running anything expensive, destructive, or going into a report.

LongSQLreviewcorrectness
Review this query for correctness. I have not run it yet. Do not tell me it looks good.

Check in this order:
1. **Grain**: what is one output row? Does any join multiply rows before aggregation, inflating the sums?
2. **Filters**: does any WHERE condition on an outer-joined table silently convert it to an inner join?
3. **NULLs**: in join keys, in NOT IN lists, in comparisons, inside aggregates.
4. **Dates**: inclusive or exclusive boundaries, timezone, whether BETWEEN is dropping the last day.
5. **Aggregates**: COUNT(*) against COUNT(column), averages of averages, SUM over a duplicated row set.
6. **Destructive statements**: any UPDATE or DELETE without the WHERE clause I intended, or whose WHERE matches more than I think.

Give a verdict: safe to run, run with caveats, or do not run. Then give me one cheap query that verifies your main concern before I run the real one.

Query:

Making it yours

  • Paste your own material where the prompt asks for it. Everything above that line is instruction, not content.
  • Delete any rule that does not apply to you. A shorter prompt that fits beats a thorough one that does not.
  • If the answer comes back vague, add a line saying what you do not want. Constraints work better than encouragement.

Correctness checks. Catching the join that duplicates rows, the NULL that drops them, and the GROUP BY that lies.

Related prompts

Find where this join is duplicating rowsYour totals are suspiciously round multiples of what they should be.Check my aggregation for grouping trapsAny query with GROUP BY that feeds a number someone will act on.Hunt every NULL trap in this queryWhen a count came back lower than expected and nothing looks wrong.Can any of these joins multiply rows?Totals look inflated and you suspect the join before the data.Am I counting the right thing?A count feeds a number someone will act on.Where could NULL change this result?A count came back lower than expected and nothing looks wrong.

Keep this one

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