Availability Table

Each Item or Establishment record can have a multiple places where they are available. This table connects Items and Establishments with the Regions and/or Locations where they can be found.

For example a type of ice cream may be found in multiple regions across the country as well as in particular Establishment Locations.

An Establishment like a grocery store or a restaurant can also be found in multiple regions across the country as well as in particular Locations. That Establishment can also have multiple Items that are found in the database.

The Item_ID and Establishment_ID fields can provide connection between those tables as well as providing connections between those tables and the Region and Location tables.

Table Layout

Column	Type	Length	Description
Availability_ID	Number (Long)	4	Unique ID for each availability record.
Item_ID	Number (Long)	4	Record ID of the item that this record is associated with. (May be Null)
Establishment_ID	Number (Long)	4	Record ID of the Establishment that this record is associated with. (May be Null)
Region_ID	Number (Long)	4	Record ID of the region record that describes the region where the associated item can be found. (May be Null)
Location_ID	Number (Long)	4	Record ID of the location record that describes a location where the associated item can be found. (May be Null)
Modified	Date/Time	8	Timestamp when this record was last modified.
Modified_By	Number (Long)	4	Record ID for the food detective that last updated this record.
Created	Date/Time	8	Timestamp when record was created.
Created_By	Number (Long)	4	Record ID for the food detective that created the record
Confirmed	Date/Time	8	Timestamp when the information was confirmed by a second food detective.
Confirmed_By	Number (Long)	4	Record ID for the food detective that provided the second confirmation.

Relationships

These records are used by the Item and Establishment tables. Each record in those tables can point to one or more records in this table. That is a one to many relationship from those records to these records.

Each of these records can point to one record in the Region table and one record in the Location table. Each record in those tables can point to one or more records in this table. That is a one to many relationship from those records to these records.

The Modified_By, Created_By and Confirmed_By fields in these records each point to single records in the Food Detective table. Because a food detective can create multiple entries in the database, this can produce a many to one relationship between these records and the Food Detective records.