Conditionally update JSON column - json

Question

I have a table which has ID & JSON columns. ID is auto incrementing column. Here are my sample data.
Row 1
1 | {
"HeaderInfo":
{
"Name": "ABC",
"Period": "2010",
"Code": "123"
},
"HData":
[
{ "ID1": "1", "Value": "$1.00", "Code": "A", "Desc": "asdf" },
{ "ID1": "2", "Value": "$1.00", "Code": "B", "Desc": "pqr" },
{ "ID1": "3", "Value": "$1.00", "Code": "C", "Desc": "xyz" }
]
}
Row 2
2 | {
"HeaderInfo":
{
"Name": "ABC",
"Period": "2010",
"Code": "123"
},
"HData":
[
{ "ID1": "76", "Value": "$1.00", "Code": "X", "Desc": "asdf" },
{ "ID1": "25", "Value": "$1.00", "Code": "Y", "Desc": "pqr" },
{ "ID1": "52", "Value": "$1.00", "Code": "Z", "Desc": "lmno" },
{ "ID1": "52", "Value": "$1.00", "Code": "B", "Desc": "xyz" }
]
}
and it keep goes. Items inside the HData section is infinite. It can be any numbers of items.
On this JSON I need to update the Value = "$2.00" where "Code" is "B". I should be able to do this with 2 scenarios. My parameter inputs are #id=2, #code="B", #value="$2.00". #id sometimes will be null. So,
If #id is null then the update statement should go through all records and update the Value="$2.00" for all items inside the HData section which has Code="B".
If #id = 2 then the update statement should update only the second row which Id is 2 for the items which Code="b"
Appreciate your help in advance.
Thanks

Answer 1

See DB Fiddle for an example.
declare #id bigint = 2
, #code nvarchar(8) = 'B'
, #value nvarchar(8) = '$2.00'
update a
set json = JSON_MODIFY(json, '$.HData[' + HData.[key] + '].Value', #value)
from so75416277 a
CROSS APPLY OPENJSON (json, '$.HData') HData
CROSS APPLY OPENJSON (HData.Value, '$')
WITH (
ID1 bigint
, Value nvarchar(8)
, Code nvarchar(8)
, [Desc] nvarchar(8)
) as HDataItem
WHERE id = #id
AND HDataItem.Code = #Code
The update / set statement says we want to replace the value of json with a new generated value / functions exactly the same as it would in any other context; e.g. update a set json = 'something' from so75416277 a where a.column = 'some condition'
The JSON_MODIFY does the manipulation of our json.
The first input is the original json field's value
The second is the path to the value to be updated.
The third is the new value
'$.HData[' + HData.[key] + '].Value' says we go from our JSON's root ($), find the HData field, filter the array of values for the one we're after (i.e. key here is the array item's index), then use the Value field of this item.
key is a special term; where we don't have a WITH block accompanying our OPENJSON statement we get back 3 items: key, value and type; key being the identifier, value being the content, and type saying what sort of content that is.
CROSS APPLY allows us to perform logic on a value from a single DB rowto return potentially multiple rows; e.g. like a join but against its own contents.
OPENJSON (json, '$.HData') HData says to extract the HData field from our json column, and return this with the table alias HData; as we've not included a WITH, this HData column has 3 fields; key, value, and type, as mentioned above (this is the same key we used in our JSONMODIFY).
The next OPENJSON works on HData.Value; i.e. the contents of the array item under HData. Here we take the object from this array (i.e. that's the root from the current context; hence $), and use WITH to parse it into a specific structure; i.e. ID1, Value, Code, and Desc (brackets around Desc as it's a keyword). We give this the alias HDataItem.
Finally we filter for the bit of the data we're interested in; i.e. on id to get the row we want to update, then on HDataItem.Code so we only update those array items with code 'B'.

Answer 2

Try the below SP.
CREATE PROC usp_update_75416277
(
#id Int = null,
#code Varchar(15),
#value Varchar(15)
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #SQLStr Varchar(MAX)=''
;WITH CTE
AS
( SELECT ROW_NUMBER()OVER(PARTITION BY YourTable.Json ORDER BY (SELECT NULL))RowNo,*
FROM YourTable
CROSS APPLY OPENJSON(YourTable.Json,'$.HData')
WITH (
ID1 Int '$.ID1',
Value Varchar(20) '$.Value',
Code Varchar(20) '$.Code',
[Desc] Varchar(20) '$.Desc'
) HData
WHERE (#id IS NULL OR ID =#id)
)
SELECT #SQLStr=#SQLStr+' UPDATE YourTable
SET [JSON]=JSON_MODIFY(YourTable.Json,
''$.HData['+CONVERT(VARCHAR(15),RowNo-1)+'].Value'',
'''+CONVERT(VARCHAR(MAX),#value)+''') '+
'WHERE ID ='+CONVERT(Varchar(15),CTE.ID) +' '
FROM CTE
WHERE Code=#code
AND (#id IS NULL OR ID =#id)
EXEC( #SQLStr)
END