The `$metadata` address answers the data model of the database: which entity sets it offers, which columns each of them has and what type those columns are. It is the request a client makes first, because the names in every other request come from it.
## Request
```text
GET .../odata4/$metadata
```
## Answer
The answer is an EDMX document. One entity type and one entity set per table, abbreviated here to two columns:
```xml
<edmx:Edmx Version="4.0" xmlns:edmx="http://docs.oasis-open.org/odata/ns/edmx">
<edmx:DataServices>
<Schema Namespace="Invantive" xmlns="http://docs.oasis-open.org/odata/ns/edm">
<EntityType Name="ExactOnlineREST.Financial.GLAccountsBulk@eol">
<Key>
<PropertyRef Name="ID" />
</Key>
<Property Name="ID" Type="Edm.Guid" Nullable="false" />
<Property Name="Code" Type="Edm.String" />
</EntityType>
<EntityContainer Name="Default">
<EntitySet Name="ExactOnlineREST.Financial.GLAccountsBulk@eol" EntityType="Invantive.ExactOnlineREST.Financial.GLAccountsBulk@eol" />
</EntityContainer>
</Schema>
</edmx:DataServices>
</edmx:Edmx>
```
## Why the Names Are Read Rather Than Composed
A table name of Invantive UniversalSQL has three parts and an alias, as in `ExactOnlineREST.Financial.GLAccountsBulk@eol`. The OData standard allows only letters, digits and underscores in a name, so a service may be configured to leave the full stop and the at sign out, which gives a different spelling for the same table.
A client therefore takes the entity set name from `$metadata` and uses it unchanged, instead of building it from the table name. That also keeps it right when a database gains or loses a data container.
## What the Data Model Does Not Hold
Two absences are worth knowing:
- there are no navigation properties, so tables are not linked to one another and `$expand` has nothing to expand. A report combines tables itself, on the columns which hold the keys;
- a table is offered with at most 1,000 columns. A wider table has the remainder absent here and in every answer.
## Related Metadata
The tables of a database are one kind of metadata. The user and the databases an account may reach are answered by two addresses of their own, described in [[Invantive Bridge Online/Metadata|Metadata]].