I am using Firebase's Realtime Database with node and I find that the only way to check that a key exists is to return all the data
{
"salas" : {
"sala01" : {
"activa" : true,
"fechaComienzo" : "2021-10-16 07:09:00Z",
"fechaCreacion" : "2021-10-16 07:09:24Z",
"nombre" : "test",
"masInfo": {
...
}
},
"sala02" : {
"activa" : true,
"fechaComienzo" : "2021-10-16 07:09:00Z",
"fechaCreacion" : "2021-10-16 07:09:24Z",
"nombre" : "test",
"masInfo": {
...
}
}
}
}
async function checkExists(_ref, key) {
const q = query(_ref, ...[orderByKey(), equalTo(key)])
const datos = await get(q);
console.log('@info', q, datos);
return datos.exists();
}
const _ref = ref(getDatabase())
checkExists(_ref, 'sala01')
With the above example, if I want to know if sala01 exists, it brings me every node with its descendants.
I wonder if there is any other way to simply check if sala01 exists without bringing me the entire node or if there is some trick to bring a node with a depth as if I have seen in the REST API documentation, shallow
This sort of query is more complex than needed:
const q = query(_ref, ...[orderByKey(), equalTo(key)])
If you know the key of a node already, you don't need to use a query, but can access that key directly.
async function checkExists(_ref, key) {
const ref = child(_ref, key)
const datos = await get(ref);
return datos.exists();
}
This won't read read the entire /_ref node, but will read the entire /_ref/$key node. There is no way to test for the existence of a path without reading that path.