T-SQL: how to process JSON elements with dot in their names? - json

Question

I have JSON object I need to process, using T-SQL. I can successfully retrieve all the elements, except those, having "." (dot) in their names, e.g. System.State, System.UserName. Can one advise how it can be addressed, please?
DECLARE #v_Json NVARCHAR(MAX) = N'{
"count": 56,
"value": [{
"id": 1,
"workItemId": 1234,
"fields": {
"MainValue": {"newValue": 98765},
"System.UserName": "User Name 1",
"System.Id": {
"newValue": 1234
},
"System.State": {
"newValue": "New"
}
}
},
{
"id": 2,
"workItemId": 1234,
"fields": {
"MainValue": {"newValue": 123456, "oldValue": 98765},
"System.UserName": "User Name 2",
"System.State": {
"oldValue": "new",
"newValue": "Defined"
}
}
}
]
}';
--SELECT F.[System.State]
--FROM OPENJSON (#v_Json)
-- WITH ([count] int,
-- value nvarchar(MAX) AS JSON) J
-- CROSS APPLY OPENJSON(J.value)
-- WITH ([System.State] NVARCHAR(50)) F;
SELECT JSON_VALUE(v.value, '$.id') AS id,
JSON_VALUE(v.value, '$.workItemId') AS workItemID,
JSON_VALUE(v.value, '$.fields.MainValue.newValue') AS MainValue,
JSON_VALUE(v.value, '$.fields.System.UserName') AS itemUserName,
JSON_VALUE(v.value, '$.fields.System.State') AS itemState,
JSON_VALUE(v.value, '$.fields.System.State.newValue') AS itemStateNewValue
FROM OPENJSON(#v_Json, '$.value') AS v
Edited to add a result screen, where I would expect to see, for example, "User Name 1" in column itemUserName.

Answer 1

It should be enough to use quotes in your JSON path:
JSON_VALUE(v.value, '$.fields."System.UserName"') AS itemUserName,
This returns with values:
DECLARE #v_Json NVARCHAR(MAX) = N'{
"count": 56,
"value": [{
"id": 1,
"workItemId": 1234,
"fields": {
"MainValue": {"newValue": 98765},
"System.UserName": "User Name 1",
"System.Id": {
"newValue": 1234
},
"System.State": {
"newValue": "New"
}
}
},
{
"id": 2,
"workItemId": 1234,
"fields": {
"MainValue": {"newValue": 123456, "oldValue": 98765},
"System.UserName": "User Name 2",
"System.State": {
"oldValue": "new",
"newValue": "Defined"
}
}
}
]
}';
--the query
SELECT JSON_VALUE(v.value, '$.id') AS id,
JSON_VALUE(v.value, '$.workItemId') AS workItemID,
JSON_VALUE(v.value, '$.fields.MainValue.newValue') AS MainValue,
JSON_VALUE(v.value, '$.fields."System.UserName"') AS itemUserName,
JSON_VALUE(v.value, '$.fields."System.State".oldValue') AS itemState,
JSON_VALUE(v.value, '$.fields."System.State".newValue') AS itemStateNewValue
FROM OPENJSON(#v_Json, '$.value') AS v;

Answer 2

To repeat my answer from SQL Server Central, with the 3rd set of sample data I was provided (the above is the 4th..):
DECLARE #v_Json NVARCHAR(MAX) = N'{
"count": 56,
"value": [{
"id": 1,
"workItemId": 1234,
"fields": {
"System.Id": {
"newValue": 1234
},
"System.State": {
"newValue": "New"
}
}
},
{
"id": 2,
"workItemId": 1234,
"fields": {
"System.State": {
"oldValue": "new",
"newValue": "Defined"
}
}
}
]
}';
SELECT F.[System.State]
FROM OPENJSON (#v_Json,'$.value')
WITH (fields nvarchar(MAX) AS JSON ) J
CROSS APPLY OPENJSON(J.fields)
WITH ([System.State] nvarchar(MAX) AS JSON) F;
Which returns the dataset below:
System.State
-----------------------------------------
{
"newValue": "New"
}
{
"oldValue": "new",
"newValue": "Defined"
}
db<>fiddle

Answer 3

This opens and flattens the JSON and assigns unique column names
select *
from openjson (#v_Json) with ([count] int,
[value] nvarchar(MAX) AS JSON) J
cross apply openjson(j.[value])
with (id int,
workItemId int,
fields nvarchar(max) as json) v
cross apply openjson(v.fields) with ([System.Id] nvarchar(max) as json,
[System.State] nvarchar(max) as json) f
outer apply openjson(f.[System.Id]) with (sys_id_newValue int '$.newValue',
sys_id_oldValue int '$.oldValue') si
outer apply openjson(f.[System.State]) with (sys_st_newValue nvarchar(4000) '$.newValue',
sys_st_oldValue nvarchar(4000) '$.oldValue');