How can I document SQLite integrity rules for a small teaching database?
Quick answer
Document integrity rules one table at a time. For each table, record its purpose, columns, key rules, relationships, uniqueness requirements, checks, and defaults. For every rule, include the relevant declaration from the schema, a plain-language explanation, and a small example of what it allows or disallows. Mark assumptions and unresolved questions explicitly, and keep operational migration steps in a separate document.
The question, the details, the next step.
I’m preparing a small SQLite database for a class. What should a schema reference cover so students can understand the integrity rules without reading a migration guide?
Make the reference a guide to the rules the schema is intended to express, not a record of how to change the database. Start with a short purpose statement and a list of tables. Then give each table its own section with:
- What one row represents.
- Its columns and their intended meanings.
- Its primary-key rule and any relationship to another table.
- Any uniqueness, check, or default rule.
- A plain-language reason for each rule.
For clarity, show the relevant declaration as written in your schema and explain it separately. That lets a student compare the documented intent with the actual declaration without mistaking an explanation for executable SQL. If you have not settled a rule, label it “open question” rather than presenting a guess as fact.
How do I explain a rule in a way a beginner can actually use?
Pair each rule with a short “meaning” and “example” entry. Keep examples small, and state that they are illustrative assumptions about the teaching database.
For example, assume a class exercise has a students table and each student has a course email:
- Rule: email is unique.
- Meaning: the design intends each student row to have a different email value.
- Example: a second row using an email already assigned to another student conflicts with the documented rule.
- Why it matters: the class can use the email value to distinguish the example student records.
This example describes the intended rule; it does not establish how a particular schema declaration behaves in every situation. Include the actual declaration beside it, and have the instructor review any unclear behavior rather than relying on this prose alone. For checks and defaults, explain the intended boundary or starting value in everyday language, then include one simple example.
Could you give me a reusable fill-in template, including relationships between tables?
Copy this once per table. The names and rules below are placeholders, not a recommended schema:
Table: [table_name]
Purpose: One row represents [plain-language description].
Columns
[column_name]—[meaning]; declaration:[type or relevant declaration].
Primary key
- Columns:
[column or columns] - Intended rule:
[what identifies a row] - Declaration:
[paste relevant schema text]
Relationships
- This table refers to:
[other table and column, or “none”] - Intended meaning:
[what the connection represents] - Declaration:
[paste relevant schema text]
Uniqueness
- Applies to:
[column or column group] - Intended rule and reason:
[explain] - Declaration:
[paste relevant schema text]
Checks
- Intended boundary:
[describe in plain language] - Example:
[one illustrative value or case] - Declaration:
[paste relevant schema text]
Defaults
- Column:
[column_name] - Intended starting value and reason:
[explain] - Declaration:
[paste relevant schema text]
Questions or assumptions: [list unresolved decisions; name who should confirm them]
How should I review the finished reference and keep it from becoming a migration guide?
Read each section alongside the schema and check that the pasted declaration and explanation refer to the same rule. Ask whether a student could tell what each key, relationship, uniqueness rule, check, and default is intended to mean. Keep examples clearly labeled as examples, and mark rules that still need confirmation.
For scope, retain material that helps a reader understand the current design. Put instructions about altering tables, sequencing changes, backups, or deployment in a separate migration document. The reference can mention that a rule is unresolved or that the schema needs review; it should not imply that this guide verifies the database or tests every case.
A practical checklist
Give every table a one-sentence purpose and describe what one row represents.
Record key and relationship rules with the relevant schema declaration and a plain-language explanation.
Document each uniqueness rule, check, and default separately, including its purpose and a small illustrative example.
Label placeholders, assumptions, and unresolved questions so readers do not confuse them with confirmed design decisions.
Compare each explanation with the schema, and move database-change procedures into a separate guide.
A few more useful answers
Should I copy the full schema into the reference?
Include enough of the relevant declaration for readers to connect each explanation to the schema. If the full schema is long, keep the reference focused on rule-related excerpts and identify the table or section they come from.
Should I document a rule that has not been decided yet?
Yes, but label it as an open question or assumption and say who should confirm it. Do not write a tentative choice as though it were an established rule.
Does a written reference prove the database enforces every rule?
No. Documentation describes intent and declarations; by itself, it does not verify runtime behavior or show that every case has been tested.