Item Types & Fields
This is the part of Ohmventory's model that makes it more than a flat list of named objects. An Item Type is a reusable category template ("Resistor," "Battery," "Book") that determines which custom Fields an Item of that type carries — and, because types can be nested, more specific types automatically inherit the fields of their broader ancestors.
Item Fields
A Field is a single named attribute with a specific data kind. Ohmventory supports these field kinds:
| Kind | Stores | Example |
|---|---|---|
| Text | A short string | Color, Package |
| Number | A plain number | Tolerance (%), Pin Count |
| Select | One value from a fixed list of options you define | Connector Type: USB-A / USB-C / Barrel Jack |
| Unit Value | A number paired with a unit, normalized for comparison/search | Resistance: 10 kΩ |
| Date | A calendar date | Purchase Date, Warranty Expiry |
| Link | A URL | Datasheet link |
| Person | A reference to a member of your Organization | Author (for a book) |
| Image | A photo | (used internally for image fields) |
A Field is defined once (e.g. "Resistance," kind Unit Value, dimension Electrical Resistance) and then attached to one or more Item Types.
Item Types form a hierarchy
Types can have a parent type and any number of sub-types, and a sub-type inherits every field its ancestors define, on top of whatever fields it adds itself:
Electronics (fields: Manufacturer, Datasheet URL)
└─ Passive
└─ Resistor (adds: Resistance, Tolerance, Power Rating)
An Item typed as "Resistor" ends up with Manufacturer and Datasheet URL (inherited from Electronics) plus Resistance, Tolerance, and Power Rating (defined on Resistor itself) — without anyone having to redefine Manufacturer/Datasheet URL on every leaf type. A sub-type can also override an inherited field's settings, such as making an optional field required.
Some types in the hierarchy — like "Electronics" or "Passive" above — exist purely to organize the tree and group shared fields. These are marked abstract: they can have sub-types and can be picked as a filter, but an Item can't be directly assigned to an abstract type — only to one of its concrete descendants.
Required fields and defaults
A Field attached to a Type can be marked required and can be given a default value. If a required field has a default, you don't have to type a value for it when creating an Item — the default is applied automatically. You only get blocked if a required field has neither a value you entered nor a default to fall back on.
Global catalog vs. your Organization's own types
Ohmventory ships with a broad, pre-built library of Item Types and Fields covering electronics parts, tools, hardware, general household goods, and more (see the Item Type Catalog feature for how to browse and import from it). These library categories are global — shared, read-only starting points every Organization can use.
Your Organization can also define entirely custom Item Types and Fields of its own, private to your Organization, either from scratch or as sub-types/extensions of a global type. This hybrid model means you get a useful baseline taxonomy immediately, without being limited to it.
:::info Screenshot placeholder The Item Type detail page: breadcrumb showing the type's ancestor chain, a table of its effective fields (marking which are inherited vs. defined directly on this type), and controls to attach a new field or create a sub-type. :::
Why this matters for search and reporting
Because Field values are typed (not free text) and Unit Value fields are stored against a real Unit, Ohmventory can do things a flat spreadsheet can't: filter "all resistors between 1kΩ and 5kΩ" correctly even if some were entered in Ω and others in MΩ, or sort a list of items by a numeric field. See Search for the parametric filtering this enables.