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 diagram tool writes a Mermaid erDiagram from CREATE TABLE statements you paste. You paste that sketch into a Mermaid viewer. The relationship tool lists a column, the table it references, and the referenced column. If no REFERENCES clause is present, it says so.
The sketch is not the production diagram until a person has checked the keys. Do not apply a DDL change during the reading. One schema you administer.
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.
- Paste one CREATE TABLE.
- Read the Mermaid sketch.
- Read the REFERENCES list.
- Do not apply DDL.
- Stop.
Mistakes that outlive the statement
How to Draw an ER Diagram goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- DDL applied during the reading.
- A relationship invented where REFERENCES was missing.
- A schema you do not administer.
Decisions to write down
One decision for How to Draw an ER Diagram: The sketch was read. Missing REFERENCES were written down. Nothing was applied. And the schema is yours.
Checks before you call it done
Confirm this before you call the change done: The tables are written. The references are written. Nothing was applied. The sketch is still a sketch. And the database is yours. If one of those fails, stop.
Before you leave the database
How to Draw an ER Diagram 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
These tools run in the browser on this site. They do not log into your machines.
Related pillar guides
More in this cluster
The pillar for this page, and the next published pages filed with it.