H
HeislerKurt
I’m building a database to manage computer assets in an organization.
I’ve found several examples (including the MS Access template) but
none which take into account more complicated data needs.
The data model I’ve created so far is pictured here:
http://img155.imageshack.us/my.php?image=datamodelforassetdatabase3.jpg
The entities are:
- Buildings
- Rooms
- Wall Jacks
- Employees
- Assets
- AssetType (e.g., PC, monitor, printer)
- AssetSubType (e.g., LCD, CRT)
- AssetManufacturers
BUILDINGS, ROOMS, AND EMPLOYEES
1. A building can have one or more rooms.
2. A room can have one or more employees.
3. An employee can be assigned to one or more rooms (most likely in
different buildings).
4. A room can have one or more wall jacks.
ASSETS
For each asset, I need to store the following details:
- Which employee it’s assigned to (but some assets - like a network
printer in the hallway - won't be assigned to a particular employee)
- Which wall jack it’s plugged in to
- Its asset type (e.g., computer, monitor)
- Its asset subtype, if any (e.g., LCD, CRT)
- Its manufacturer
- Its serial number, etc.
1. An employee can have one or more assets (e.g., a computer, a
monitor, and a printer).
2. An asset can be plugged into only one wall jack.
3. A manufacturer (e.g., Dell) can be assigned to one or more assets.
4. An asset type (e.g., computer, monitor) can be assigned to one or
more assets.
5. An asset type can have one or more subtypes (e.g., a monitor can be
either an LCD or CRT; a computer can be either a "small form factor"
or a "midsize tower").
###
I can’t figure out these issues:
1. How to relate tblWallJacks to tblAssets. If I make a link from the
PK of tblWallJacks (WallJack ID) to a FK of tblAssets (WallJackID),
Access will see it as a one to many. This would be wrong because a
wall jack can have only one asset, and vice versa. Perhaps I shouldn’t
make a link, and instead just use a lookup table for WallJackID in
tblAssets. On a form, I’d use code to synchronize the WallJack combo
box options with the Room selected in the Room combo box.
2. Since an employee can be assigned to more than room, which may be
in a different building, do I need to make a relationship between
tblEmployees and tblBuildings, or will the tblRoomToEmployees junction
table establish the relationship?
3. How to handle the situation when an asset isn’t assigned to a
particular user (like a network printer in the hallway). Perhaps I
could creating a fake user? The room could be called “Hallway1” with
wall jack “X1” for example. I would then assign the asset to the fake
user, who lives in Hallway1. I’d have to create additional fake users
to handle other “hallway” assets, which could pose problems
Thank you for any advice on this!
Kurt
I’ve found several examples (including the MS Access template) but
none which take into account more complicated data needs.
The data model I’ve created so far is pictured here:
http://img155.imageshack.us/my.php?image=datamodelforassetdatabase3.jpg
The entities are:
- Buildings
- Rooms
- Wall Jacks
- Employees
- Assets
- AssetType (e.g., PC, monitor, printer)
- AssetSubType (e.g., LCD, CRT)
- AssetManufacturers
BUILDINGS, ROOMS, AND EMPLOYEES
1. A building can have one or more rooms.
2. A room can have one or more employees.
3. An employee can be assigned to one or more rooms (most likely in
different buildings).
4. A room can have one or more wall jacks.
ASSETS
For each asset, I need to store the following details:
- Which employee it’s assigned to (but some assets - like a network
printer in the hallway - won't be assigned to a particular employee)
- Which wall jack it’s plugged in to
- Its asset type (e.g., computer, monitor)
- Its asset subtype, if any (e.g., LCD, CRT)
- Its manufacturer
- Its serial number, etc.
1. An employee can have one or more assets (e.g., a computer, a
monitor, and a printer).
2. An asset can be plugged into only one wall jack.
3. A manufacturer (e.g., Dell) can be assigned to one or more assets.
4. An asset type (e.g., computer, monitor) can be assigned to one or
more assets.
5. An asset type can have one or more subtypes (e.g., a monitor can be
either an LCD or CRT; a computer can be either a "small form factor"
or a "midsize tower").
###
I can’t figure out these issues:
1. How to relate tblWallJacks to tblAssets. If I make a link from the
PK of tblWallJacks (WallJack ID) to a FK of tblAssets (WallJackID),
Access will see it as a one to many. This would be wrong because a
wall jack can have only one asset, and vice versa. Perhaps I shouldn’t
make a link, and instead just use a lookup table for WallJackID in
tblAssets. On a form, I’d use code to synchronize the WallJack combo
box options with the Room selected in the Room combo box.
2. Since an employee can be assigned to more than room, which may be
in a different building, do I need to make a relationship between
tblEmployees and tblBuildings, or will the tblRoomToEmployees junction
table establish the relationship?
3. How to handle the situation when an asset isn’t assigned to a
particular user (like a network printer in the hallway). Perhaps I
could creating a fake user? The room could be called “Hallway1” with
wall jack “X1” for example. I would then assign the asset to the fake
user, who lives in Hallway1. I’d have to create additional fake users
to handle other “hallway” assets, which could pose problems
Thank you for any advice on this!
Kurt