Pul in DB naming notes from old repo
This commit is contained in:
parent
a007bdd8c3
commit
478db3ad3c
112
dbnames.md
Normal file
112
dbnames.md
Normal file
@ -0,0 +1,112 @@
|
|||||||
|
The website schema needs to be discoverable. The `sqlite_schema` table (or the `table_list` pragma) and the `table_info` pragma are essential.
|
||||||
|
|
||||||
|
The following facts need to be discoverable:
|
||||||
|
- The name of each node type.
|
||||||
|
- The fields in each node type.
|
||||||
|
- The type of each field in a node.
|
||||||
|
- The subfields in each field type.
|
||||||
|
- The type of each subfield in a field.
|
||||||
|
- Whether a field or subfield is repeated, optional, or single.
|
||||||
|
- Whether a field has an application-primitive, but non-sqlite-primitive, type, such as datetime.
|
||||||
|
- Discriminated union fields.
|
||||||
|
|
||||||
|
Field types need to be acyclic. *Do they really?*
|
||||||
|
|
||||||
|
Field values need to be deleted when the node that contains them is deleted.
|
||||||
|
|
||||||
|
If field types are namespaced to a node type, then SQLite schema object naming will get harder.
|
||||||
|
Maybe just let them be shared.
|
||||||
|
|
||||||
|
```
|
||||||
|
(node blogpost)
|
||||||
|
(composite-field car)
|
||||||
|
(node "car review")
|
||||||
|
(field cars)
|
||||||
|
(field car)
|
||||||
|
node:blogpost
|
||||||
|
field:
|
||||||
|
|
||||||
|
(: road-review node)
|
||||||
|
(: car composite-field)
|
||||||
|
-- Entity names must be qualified by their type/kind, or there can't be e.g. a node type and field type that share a name.
|
||||||
|
-- I think qualification is best, because then SQLite will prevent duplicates by the requirement that table names be unique.
|
||||||
|
(list (: car composite-field))
|
||||||
|
|
||||||
|
|
||||||
|
create table "car:composite-field" (
|
||||||
|
id integer primary key,
|
||||||
|
"Make" text not null,
|
||||||
|
"Model" text not null,
|
||||||
|
"Year" text not null,
|
||||||
|
"Test distance" int not null,
|
||||||
|
"Test date:date" text not null,
|
||||||
|
);
|
||||||
|
|
||||||
|
create table "road review.cars:(list-field (road review:node))" (
|
||||||
|
"Road review:node" int primary key references "road review:node",
|
||||||
|
"Car:composite-field" int primary key references "car:composite-field",
|
||||||
|
);
|
||||||
|
|
||||||
|
create table "Road review:node" (
|
||||||
|
id integer primary key,
|
||||||
|
"Title" text not null,
|
||||||
|
"Cars:(list car)"
|
||||||
|
);
|
||||||
|
|
||||||
|
(field car)
|
||||||
|
(node review)
|
||||||
|
(list (field car) (node review)) -- If we parameterize each list relation by both the listed field and the containing node or field, then we've basically monomorphized it.
|
||||||
|
-- However, that won't cut it if a node or field contains multiple lists of the same type. We also need to parameterize list relations by the field name in the containing node or field.
|
||||||
|
```
|
||||||
|
|
||||||
|
```
|
||||||
|
primitive-field-type := int | text | date |
|
||||||
|
record-field-type := (record <field-type-name> ((<field-name> <field-type>) ...))
|
||||||
|
variant-field-type := (variant <field-type-name> ((<field-name> <field-type>) ...))
|
||||||
|
field-type := (field <field-type-name>)
|
||||||
|
node-type := (node <node-type-name>)
|
||||||
|
parent-object-type := <field-type> | <node-type>
|
||||||
|
list := (list <element-type> <parent-object-type> <field-name>)
|
||||||
|
```
|
||||||
|
|
||||||
|
|
||||||
|
```
|
||||||
|
(record car)
|
||||||
|
(id integer)
|
||||||
|
(make text)
|
||||||
|
(model text)
|
||||||
|
(year text)
|
||||||
|
(test-distance integer)
|
||||||
|
(test-date date)
|
||||||
|
|
||||||
|
(list car)
|
||||||
|
(node road-review)
|
||||||
|
(car car)
|
||||||
|
|
||||||
|
(node road-review)
|
||||||
|
(id integer)
|
||||||
|
(title text)
|
||||||
|
(cars (list car))
|
||||||
|
```
|
||||||
|
|
||||||
|
```
|
||||||
|
(node <node-type-name>)
|
||||||
|
id integer primary key
|
||||||
|
(<composite-type-name> <field-name>) <db-type> ...
|
||||||
|
(list <composite-type-name>)
|
||||||
|
id
|
||||||
|
(list-item <composite-type-name>)
|
||||||
|
list-id references (list <composite-type-name>) primary key
|
||||||
|
sequence-number primary key
|
||||||
|
item-id references (composite-value <composite-type-name>)
|
||||||
|
(composite-value <composite-type-name>)
|
||||||
|
id
|
||||||
|
-- This indirection is so that SQLite will prevent duplicate field type names in table names.
|
||||||
|
<record|variant>-value-id references (<record|variant>-value <composite-type-name>)
|
||||||
|
(record-value <composite-type-name>)
|
||||||
|
id integer primary key
|
||||||
|
(<composite-type-name> <field-name>) <db-type> ...
|
||||||
|
(variant-value <composite-type-name>)
|
||||||
|
id integer primary key
|
||||||
|
(<composite-type-name> <field-name>) <db-type> ...
|
||||||
|
```
|
Loading…
Reference in New Issue
Block a user