This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
The generator writes one statement shape for each engine: ON CONFLICT, ON DUPLICATE KEY, and MERGE. The sample values are placeholders. The INSERT-to-UPDATE tool turns one INSERT into an UPDATE and uses the first column as the WHERE key.
Review that key before anyone runs an update. Do not run either draft during the reading. One statement, on a copy, is the later window. A MERGE that matches the wrong key updates the wrong rows.
192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the database named in the ticket. Read the draft, then the database, then decide.
Rollback is the backup, the file, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Name the table and the key.
- Read all three shapes.
- Read which column becomes WHERE.
- Do not run the draft.
- Stop.
Mistakes that outlive the statement
Upsert in SQL (MERGE, ON CONFLICT, ON DUPLICATE KEY) goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- The draft run during the reading.
- The WHERE key left unread.
- Sample values left in a script you save.
- A production table changed from the page.
Decisions to write down
One decision for Upsert in SQL (MERGE, ON CONFLICT, ON DUPLICATE KEY): The key is written. The engine is written. Nothing was run. And the WHERE column was read.
Checks before you call it done
Confirm this before you call the change done: The key is written. The engine is written. The WHERE column was read. Nothing was run. And the database is yours. If one of those fails, stop.
-- One upsert statement.
-- The first column of an INSERT-to-UPDATE sketch is the WHERE key.
-- Do not run it during the reading.Before you leave the database
Upsert in SQL (MERGE, ON CONFLICT, ON DUPLICATE KEY) ends when the database in the prompt is the database in the ticket. If it is not, you are on the wrong database. Stop.
The draft stays a draft until a person has read the names in it. A generator does not log into the database. You delete a line that names a host, a database, or an account you did not write down.
192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a database because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. A sample password in a draft is replaced. It is not a password you keep.
One change is the window. If two things move and the result is wrong, you will not know which one did it.
If the same step fails twice, stop for the day. Restore the copy you took first.
A second person reads the database name and the change aloud. If they cannot find them in the ticket, the note is not done.
This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a database you do not administer. You do not disable authentication, a firewall, or TLS to make a check pass.
Tools for this guide
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