Assume documents of the following schema
{
"id": 1,
"children":[
{"id": "a", "name":"al"},
{"id": "b", "name":"bob"}
]
}
I want to return an array of arrays of all children but filtered on the id property at the root level. Below are the most the known alternatives and limitations:
SELECT * FROM c.children
The above SQL, provides the array of arrays in the right shape but it doens't allow me to filter at the ID in the ROOT level of the document.
SELECT children FROM c WHERE c.id >= 1
The above allows the filtering but returns an array of objects all with the "children" property containing the array.
SELECT child.id, child.name FROM c JOIN child in c.children WHERE c.id >= 1
The above allows the filtering but returns an array of objects. Unlike the previous example the objects are flattened to the child level e.g. property named prefix of "children" is not present.
Again the ordering and grouping children in the returned arrays returned are important on the client side, thus the desired to return all children of a parent grouped in to an array. The first query accomplishes that be doesn't allow filtering.
Please try this SQL:
SELECT value c.children FROM c WHERE c.id >= 1
Result:
[
[
{
"id": "a",
"name": "al"
},
{
"id": "b",
"name": "bob"
}
]
]
Related
I have some difficulty in writing a query to query data from nested json in Cosmos db.
Sample json -
{
"id": xyz
"items": [
{
"arr_id": 1,
"randomval": "abc"
},
{
"arr_id": 2,
"randomval": "mno"
},
{
"arr_id": 1,
"randomval": "xyz"
}
]
}
Lets say in above case, if i want to get all jsons data with arr_id = 1.
Expected Result -
{
"id": xyz
"items": [
{
"arr_id": 1,
"randomval": "abc"
},
{
"arr_id": 1,
"randomval": "xyz"
}
]
}
If i write a query like below, it still gives me entire json.
Select * from c where ARRAY_CONTAINS(c.items, {"arr_id": 1},true)
I want it to filter it items level too. I guess it just filters at header level and provides entire json where even a single arr_id matches.
You can use either
SELECT c.id, ARRAY(SELECT VALUE i FROM i in c.items where i.arr_id = 1) as items
FROM c
WHERE EXISTS(SELECT VALUE i FROM i in c.items where i.arr_id = 1)
or
SELECT c.id, ARRAY(SELECT VALUE i FROM i in c.items where i.arr_id = 1) as items
FROM c
depending on whether you expect an empty array if no arrayItem with arr_id=1 exists or you wnat to filter out those records compeletely.
Also see this link for a good overview of query options across arrays - https://devblogs.microsoft.com/cosmosdb/understanding-how-to-query-arrays-in-azure-cosmos-db/
I'm trying to understand the documentation about JOIN in Cosmos DB SQL.
In the sample JSON, each family object has a children property, like this:
First family object:
"id": "AndersenFamily",
"lastName": "Andersen",
"children": [
{
"firstName": "Henriette Thaulow",
"grade": 5
}
],
Second family object:
"id": "WakefieldFamily",
"children": [
{
"givenName": "Jesse"
}
],
Then, this JOIN operation is shown:
SELECT f.id
FROM Families f
JOIN f.children
The obvious result is the identifier of each family object.
[
{
"id": "AndersenFamily"
},
{
"id": "WakefieldFamily"
}
]
If the "JOIN" is removed, the result is exactly the same. Even I wanted to project the children, I could just use SELECT f.id, f.children and there would be no reason to join f.children.
The only difference I observe is if a family object didn't have a children property. Then the joining on f.children would exclude the family object from the results.
So what is the point of a JOIN in Cosmos DB SQL without combining it with IN? Is there any real use cases for it?
I have a large collection of json documents whose structure is in the form:
{
"id": "00000000-0000-0000-0000-000000001122",
"typeId": 0,
"projectId": "p001",
"properties": [
{
"id": "a6fdd321-562c-4a40-97c7-4a34c097033d",
"name": "projectName",
"value": "contoso",
},
{
"id": "d3b5d3b6-66de-47b5-894b-cdecfc8afc40",
"name": "status",
"value": "open",
},
.....{etc}
]
}
There may be a lot of properties in the collection, all identified by the value of name. The fields in properties are pretty consistent -- there may be some variability, but they will all have the fields that I care about. There's an Id, some labels, etc
I'm wanting to combine these with some other data in PowerBI using the projectId to create some very valuable reports.
I think what I want to do it 'normalize' this data into a table, like:
ProjectId
projectName
status
openDate
closeDate
manager
p001
contoso
open
20200101
me
etc
Where I'm at...
I can go:
SELECT c["value"] AS ProjectName
FROM c in t.Properties
WHERE c["name"] = "projectName"
... this will give me each projectName
I can do that a heap of times to get the 'values' (status, openDate, manager, etc)
If I want to combine them together then I would need to combine all those sub-queries together with 'id'. But 'id' in not in the scope of the SELECT, so how do I get it?? If I were to do this, it sounds like something that would be very expensive (RU's) to execute.
I think I'm overcomplicating this, but I cant quite get my head around the Cosmos syntax.
Help??
You can achieve it with JOINS and the WHERE expressions although the scheme is not ideal for querying and you should consider changing it.
SELECT
c['projectId'], --c.projectId also works, but value is a reserved keyword
n['value'] AS projectName,
s['value'] AS status
FROM c
JOIN n IN c.properties
JOIN s IN c.properties
WHERE n['name'] = 'projectName' AND s['name'] = 'status'
--note all filtered properties must appear exactly once for it to work properly
Edit; new query that solves the potential issue that filtered properties must appear exactly once.
SELECT
c['projectId'],
ARRAY(
SELECT VALUE n['value']
FROM n IN c.properties
WHERE n['name'] = 'projectName'
)[0] AS projectName,
ARRAY(
SELECT VALUE n['value']
FROM n IN c.properties
WHERE n['name'] = 'status'
)[0] AS status
FROM c
My document that I save in Cosmos DB looks like this:
{
"id": "abc123",
"myProperty": [
"1905844b-6ca9-4967-ba40-a736b685ca62",
"b03cc85c-ef0b-4f48-9c31-800de089190a"
]
}
As you can see, in the myProperty property, I have an array of GUID values and I want to read them as an array/list of GUID values but I'm having trouble formulating the correct SELECT statement.
The output I'm looking for is:
[
"1905844b-6ca9-4967-ba40-a736b685ca62",
"b03cc85c-ef0b-4f48-9c31-800de089190a"
]
The closest I could get is this `SELECT statement:
SELECT VALUE c.myProperty FROM c WHERE c.id = "abc123"
But this doesn't give me exactly what I want either. This gives me an array within an array i.e.
[
[
"1905844b-6ca9-4967-ba40-a736b685ca62",
"b03cc85c-ef0b-4f48-9c31-800de089190a"
]
]
What should my SELECT statement look like to get what I want?
I dont think you can ever get anything else, because cosmos db will always return an array in response to a query because potentially there can be 0-infinity results. so you will always get a top level array that will wrap all your results (even if you have only one)
This is a follow up to question 56126817
My current query
SELECT c.EventType.EndDeviceEventDetail FROM c
WHERE c.EventType.EndDeviceEventType.eventOrAction = '93'
AND c.EventType.EndDeviceEventType.subdomain = '137'
AND c.EventType.EndDeviceEventType.domain = '26'
AND c.EventType.EndDeviceEventType.type = '3'
AND ARRAY_CONTAINS(c.EventType.EndDeviceEventDetail,{"name":
"RCDSwitchReleased","value": "true" })
My Query Output
[
{
"EndDeviceEventDetail": [
{
"name": "Spontaneous",
"value": "true"
},
{
"name": "DetectionActive",
"value": "true"
},
{
"name": "RCDSwitchReleased",
"value": "true"
}
]
}
]
Question
How could change my query so that I select only the "value" of the array that contains the "name" "DetectionActive" ?
The idea behind is to filter the query on one array entry and get as output the "value" of another array entry. From reading here, UDF (not the best in this case) and JOIN should be used.
First attempt
SELECT t.value FROM c JOIN t in c.EventType.EndDeviceEventDetail
WHERE c.EventType.EndDeviceEventType.eventOrAction = '93'
AND c.EventType.EndDeviceEventType.subdomain = '137'
AND c.EventType.EndDeviceEventType.domain = '26'
AND c.EventType.EndDeviceEventType.type = '3'
AND ARRAY_CONTAINS(c.EventType.EndDeviceEventDetail,{"name":
"RCDSwitchReleased","value": "true" })
Gets Bad Request (400) error
Your idea and direction is right absolutely, I simplified and tested your sql.
SELECT detail.value FROM c
join detail in c.EventType.EndDeviceEventDetail
WHERE c.EventType.EndDeviceEventType.eventOrAction = '93'
AND ARRAY_CONTAINS(c.EventType.EndDeviceEventDetail,{"name":
"RCDSwitchReleased","value": "true" })
Found the error message as below:
It because that the value is the reserved word in cosmos db sql syntax,please refer to this case:Using reserved word field name in DocumentDB
You could try to modify the sql like:
SELECT detail["value"] FROM c