I have following table:
Id | HieararchyId | Name |
---|---|---|
1 | / | MHz |
2 | /1/ | Finance |
3 | /1/ | IT |
4 | /1/3/ | Software Development |
5 | /1/3/ | QA |
6 | /1/2/ | Accountant |
and I want to get data for my TreeView like:
[
{
"Id": 1,
"HierarchyId": "/"
"Name":"MHz",
"Children":[
{
"Id": 3,
"HierarchyId": "/1/"
"Name":"IT",
"Children":[
{
"Id": 4,
"HierarchyId": "/1/3/"
"Name":"Software Development",
"Children":[]
}
{
"Id": 5,
"HierarchyId": "/1/3/"
"Name":"QA",
"Children":[]
}
]
},
{
"Id": 2,
"HierarchyId": "/1/"
"Name":"Finance",
"Children":[
{
"Id": 6,
"HierarchyId": "/1/2/"
"Name":"Accountant",
"Children":[]
}
]
}
]
}
]
I tried with this: How to generate hierarchical JSON data
Got error: No more lock classes available from transaction.
Or is it better creating recursive function and filling the Tree
on client side
?
Update
CREATE FUNCTION dbo.GetJson (@departmentId hierarchyid)
RETURNS nvarchar(max)
AS BEGIN
RETURN (
SELECT
Id,
HierarchyId,
Name,
children = JSON_QUERY(dbo.GetJson(HierarchyId))
FROM Departments p
WHERE p.HierarchyId.IsDescendantOf(@departmentId ) = 1
FOR JSON PATH
);
END;
CodePudding user response:
The best way I have found to do this is to use a recursive function.
You can get all descendants of a node using IsDescendantOf
but you need to make sure to exclude the current node
CREATE FUNCTION dbo.GetJson (@parentID hierarchyid)
RETURNS nvarchar(max)
AS BEGIN
RETURN (
SELECT
t.Id,
t.HierarchyId,
t.Name,
children = JSON_QUERY(dbo.GetJson(t.HierarchyId))
FROM Tree t
WHERE t.HierarchyId <> @parentID
AND t.HierarchyId.IsDescendantOf(@parentID) = 1
FOR JSON PATH
);
END;
go
SELECT dbo.GetJson(hierarchyid::GetRoot());
Result
[
{
"Id": 2,
"HierarchyId": "/1/",
"Name": "Finance",
"children": [
{
"Id": 4,
"HierarchyId": "/1/3/",
"Name": "Software Development"
},
{
"Id": 5,
"HierarchyId": "/1/3/",
"Name": "QA"
},
{
"Id": 6,
"HierarchyId": "/1/2/",
"Name": "Accountant"
}
]
},
{
"Id": 3,
"HierarchyId": "/1/",
"Name": "IT",
"children": [
{
"Id": 4,
"HierarchyId": "/1/3/",
"Name": "Software Development"
},
{
"Id": 5,
"HierarchyId": "/1/3/",
"Name": "QA"
},
{
"Id": 6,
"HierarchyId": "/1/2/",
"Name": "Accountant"
}
]
},
{
"Id": 4,
"HierarchyId": "/1/3/",
"Name": "Software Development"
},
{
"Id": 5,
"HierarchyId": "/1/3/",
"Name": "QA"
},
{
"Id": 6,
"HierarchyId": "/1/2/",
"Name": "Accountant"
}
]