Turn a pasted schema and a plain-English goal into SQL—without inventing tables, and with a warning before anything destructive.

Top picks

Protocol

1. 1

   Paste schema, dialect, and the question (4 min).

   Include dialect (PostgreSQL, MySQL, BigQuery, SQL Server, SQLite), CREATE TABLE or a column list, grain/keys if you know them, and the question in one sentence. If a table is not in the paste, it does not exist for this chat.

2. 2

   Lock “never invent schema.”

   Paste the rules before the schema so the model cannot hallucinate a users.email column.

   Copy-paste prompt

   Copy

   Write SQL from a schema and a plain-English goal I will paste.
   
   Hard rules:
   - Use only tables and columns in my schema paste. Never invent a table, column, type, or join key.
   - If the goal needs a column I did not give, stop and list NEED FROM SCHEMA. Do not guess.
   - Default to a read-only SELECT (or WITH … SELECT).
   - Before any DELETE, UPDATE, DROP, TRUNCATE, MERGE, or ALTER: print a WARNING block (what rows/objects, what is irreversible) and wait for me to type ALLOW DESTRUCTIVE.
   - State dialect-specific functions only for the dialect I name.
   - Show assumptions separately from the SQL.
   
   Output:
   1) Restated goal
   2) SQL
   3) Assumptions
   4) NEED FROM SCHEMA
   5) How I should sanity-check the result (using only my columns)
   
   Confirm the rules, then wait.

3. 3

   Paste schema + goal, then review the ASSUMPTIONS list.

   Read the ASSUMPTIONS list and NEED FROM SCHEMA before you run anything. If a join key was assumed, fix the schema paste and regenerate. Never run destructive SQL blind.

   Generate command

   Copy

   Dialect, schema, and goal are below. Write the SELECT. If you must invent a column, do not—list it under NEED FROM SCHEMA. No destructive SQL unless I later type ALLOW DESTRUCTIVE.

4. 4

   Run it in your own console.

   You still execute. Prefer EXPLAIN or a LIMIT first. If you truly need a mutating statement, use the block below only after a backup you control.

   Destructive-SQL gate

   Copy

   I typed ALLOW DESTRUCTIVE. Rewrite as the mutating statement I described, with a WARNING (object, filter, irreversibility) above the SQL, and a SELECT that previews matching rows using only my schema. If the filter is missing, refuse.

When not to

• Never run destructive SQL blind. No DELETE, UPDATE, DROP, TRUNCATE, MERGE, or ALTER until you have read the ASSUMPTIONS list, typed ALLOW DESTRUCTIVE, run a preview SELECT, and have a backup you control.
• Do not let the model invent a table, column, or join key. Missing schema stays missing; it belongs on NEED FROM SCHEMA.
• Do not paste production credentials, connection strings, or real PII in the schema dump if you can use aliases.
• Skip this recipe if you do not have a schema. Describe columns first, or use the CSV recipe instead.