How to set .indexOn in firebase? - firebase

Question

This is my json structure
{
"books" : {
"sample" : {
"eight" : {
"author" : "eighta",
"name" : "eight",
"sub" : {
"subauthor" : "eightauthor",
"subname" : "general"
}
},
"eleven" : {
"author" : "twelvea",
"name" : "twelve",
"sub" : {
"subauthor" : "elevenauthor",
"subname" : "general"
}
},
"five" : {
"author" : "fivea",
"name" : "five",
"sub" : {
"subauthor" : "fiveauthor",
"subname" : "fivesub"
}
},
"four" : {
"author" : "foura",
"name" : "four",
"sub" : {
"subauthor" : "fourauthor",
"subname" : "general"
}
},
"nine" : {
"author" : "ninea",
"name" : "nine",
"sub" : {
"subauthor" : "nineauthor",
"subname" : "ninesub"
}
},
"one" : {
"author" : "onea",
"name" : "one",
"sub" : {
"subauthor" : "oneauthor",
"subname" : "onesub"
}
},
"seven" : {
"author" : "seven",
"name" : "seven"
},
"six" : {
"author" : "sixa",
"name" : "six"
},
"ten" : {
"author" : "tena",
"name" : "ten"
},
"three" : {
"author" : "threea",
"name" : "three"
},
"two" : {
"author" : "twoa",
"name" : "two"
}
}
}
}
I want to fetch data which are having subname equal to general
My index rules
{
/* Visit https://firebase.google.com/docs/database/security to learn more about security rules. */
"rules": {
".read": true,
".write": true,
"books": {
"$user_id": {
".indexOn": ["subname", "subauthor"]
}
}
}
}
}
https://myprojectpath/books/sample/eight.json?orderBy="subname"&equalTo="general"&print=pretty
Above rule is working fine. But I need to pass generic api to fetch the data where subname should be general. I cannot pass eight.json, nine.json, ten.json each time when I call. I should call only one api where it should provide the data where subname should be general.

Answer 1

If I understand you correctly you want to use a single query to search across all authors for their sub/subname property.
In that case you can define an index on books/sample for the sub/subname property of each child node:
"books": {
"sample": {
".indexOn": ["sub/subname", "sub/subauthor"]
}
}
The sample could be a $ variable here (such a $user_id), but the paths in .indexOn have to be known.
This creates an index under sample with the value of sub/subname for each child node, which you can then query with:
https://myprojectpath/books/sample.json?orderBy="sub/subname"&equalTo="general"&print=pretty