I created an API using Loopback, and connected it to a MongoDB. I loaded some data into my database via a JSON file, and I can access that data without issue.
Entire data (accessed from GET /fish)
[
{
"name": "Walleye",
"scientific": "Sander Vitreus",
"environment": "Fresh Water",
"minClimate": "0",
"maxClimate": "0",
"minDepth": "0",
"maxDepth": "27",
"avLength": "54",
"maxLength": "107",
"avWeight": "0",
"maxWeight": "11.3",
"maxAge": "29",
"description": "Occurs in lakes, pools, backwaters, and runs of medium to large rivers. Frequently found in clear water, usually near brush. Prefers large, shallow lakes with high turbidity. Rarely found in brackish waters. Feeds at night, mainly on insects and fishes (prefers yellow perch and freshwater drum but will take any fish available) but feeds on crayfish, snails, frogs, mudpuppies, and small mammals when fish and insects are scarce. Although not widely farmed commercially for consumption, large numbers are hatched and raised for stocking lakes for game fishing. Utilized fresh or frozen; eaten pan-fried, broiled, microwaved and baked.",
"id": "1"
},
{
"name": "Northern Pike",
"scientific": "Esox Lucius",
"environment": "Fresh Water",
"minClimate": "10",
"maxClimate": "28",
"minDepth": "1",
"maxDepth": "5",
"avLength": "55",
"maxLength": "137",
"avWeight": "0",
"maxWeight": "28.4",
"maxAge": "30",
"description": "Occurs in clear vegetated lakes, quiet pools and backwaters of creeks and small to large rivers. Usually solitary and highly territorial. Enters brackish water in the Baltic. Adults feed mainly on fishes, but at times feed heavily on frogs and crayfish. Cannibalism is common. In arctic lakes, it is sometimes the only species present in a given water body. In such cases, juveniles feed on invertebrates and terrestrial vertebrates; large individuals are mainly cannibals. Cannibalistic as juveniles. Feces of pike are avoided by other fish because they contain alarm pheromones. Deposits feces at specific locations, distant from its foraging area. Eggs and young are preyed upon by fishes, aquatic insect larvae, birds, and aquatic mammals. Does not generally undertake long migrations, but a few may move considerable distances. This fish can be heavily infested with parasites, including the broad tapeworm which, if not killed by thorough cooking, can infect human; is used as an intermediate host by a cestode parasite which results to large losses in usable catches of lake whitefish (Coregonus clupeaformis) in some areas; also suffers from a trematode which causes unsightly cysts on the skin. Excellent food fish; utilized fresh and frozen; eaten pan-fried, broiled, and baked. Valuable game fish. In spite of numerous attempts to culture this species, it was never entirely domesticated and does not accept artificial food. Locally impacted by habitat alterations",
"id": "2"
}
]
But if I try to access a single collection via the /fish/{id} command, I get an error!
Error:
{
"error": {
"statusCode": 404,
"name": "Error",
"message": "Unknown \"fish\" id \"\"1\"\".",
"status": 404,
"code": "MODEL_NOT_FOUND",
"stack": "Error: Unknown \"fish\" id \"\"1\"\".\n at ... (removed long path)...
}
}
How can I properly access a single collection? Using loopback, will I need to add each individual fish as a Loopback model? To me, that seems to be what this error is saying?
So I figured this out tonight.
First, I had to edit the JSON file in my API
"idInjection": false, //change from true to false
"properties": {
"_id": { //add an id field to the properties
"type": "string",
"id": true,
"generated": true
},
I then had to change the JSON data that I loaded into my database. Instead of using integers (1, 2, 3, etc.,) I had to strings. So for my Walleye model, I changed
"_id": "1"
to
"_id": "walleye"
Now I can use the GET /fish/{id} command without issues! Hope this helps anyone else who comes across it.