Manipulate JSON in SQL Server

Sql Server2016 starts to support JSON data operation. But you still need to make sure the COMPATIBILITY_LEVEL >= 130 in case your database is restored/migrated from an older version.

Please check this link for the mapping of Sql Server version and Compatibility Level.

Check the compatilibity level:

select * from sys.databases

Update the value if your Sql Server supports:

ALTER DATABASE TestDb SET COMPATIBILITY_LEVEL = 130 -- if less than 130. Examples

Following is the sample data:

DECLARE @jsonVariable NVARCHAR(MAX) SET @jsonVariable = N'[ { "Order": { "Number":"SO43659", "Date":"2011-05-31T00:00:00" }, "AccountNumber":"AW29825", "Item": { "Price":2024.9940, "Quantity":1 } }, { "Order": { "Number":"SO43661", "Date":"2011-06-01T00:00:00" }, "AccountNumber":"AW73565", "Item": { "Price":2024.9940, "Quantity":3 } } ]' select @jsonVariable as Orders into SalesReportJson Functions OPENJSON

You can also trasform the JSON Data, and save it to table

SELECT SalesOrderJsonData.* into SalesReport FROM OPENJSON (@jsonVariable) WITH ( Number varchar(200) N'$.Order.Number', Date datetime N'$.Order.Date', Customer varchar(200) N'$.AccountNumber', Quantity int N'$.Item.Quantity' ) AS SalesOrderJsonData;

Or read from SalesReportJson table directly:

select Orders.* into SalesReport from SalesReportJson cross apply openjson(Orders) WITH ( Number varchar(200) N'$.Order.Number', Date datetime N'$.Order.Date', Customer varchar(200) N'$.AccountNumber', Quantity int N'$.Item.Quantity' ) as Orders

The SalesReport table will look like:

Number Date Customer Quantity SO43659 2011-05-31 00:00:00.000 AW29825 1 SO43661 2011-06-01 00:00:00.000 AW73565 3 ISJSON

It is used to check if the data is in a valid json format.

The following sql will return 1 :

select ISJSON(Orders) from SalesReportJson JSON_VALUE

JSON_VALUEis used to extract a scalar value from a JSON string. If the value is not a scalar value, the result will be NULL . In that case, you should use JSON_QUERY instead.

For example, if we want to get the first order’s order number from the Orders column of SalesReportJson , run the following sql:

select JSON_VALUE(Orders, '$[0].Order.Number') as OrderNumber, JSON_VALUE(Orders, '$[0].Item.Quantity') as ItemQuantity, JSON_VALUE(Orders, '$[0].Order') as FirstOrder -- this will be NULL from SalesReportJson

The result will be:

OrderNumber ItemQuantity FirstOrder SO43659 1 NULL JSON_QUERY

JSON_QUERY is used to extract object or list from a JSON string. For the previous example, we can use the JSON_QUERY to get the FirstOrder object:

select JSON_QUERY(Orders, '$[0].Order') as FirstOrder -- this will be an object from SalesReportJson

The result will be :

FirstOrder { “Number”:”SO43659”, “Date”:”2011-05-31T00:00:00” } JSON_MODIFY

It updates the value of a property in a JSON string and returns the updated JSON string.

For example, we update the item price of the first order:

update SalesReportJson set Orders=JSON_MODIFY(Orders, '$[0].Item.Price', 100.0)

The result will be:

[ { "Order": { "Number": "SO43659", "Date": "2011-05-31T00:00:00" }, "AccountNumber": "AW29825", "Item": { "Price": 100.0, "Quantity": 1 } }, { "Order": { "Number": "SO43661", "Date": "2011-06-01T00:00:00" }, "AccountNumber": "AW73565", "Item": { "Price": 2024.9940, "Quantity": 3 } } ] FOR JSON

with FOR JSON , You can also format query results as JSON.

select Number as [Order.Number], Date as [Order.Date], Customer as [Account], Quantity as [Item.Quantity] from SalesReport FOR JSON PATH, ROOT('Orders') -- use PATH here to make the result nested according to the dot syntax

The result json is :

{ "Orders": [ { "Order": { "Number": "SO436592", "Date": "2011-05-31T00:00:00" }, "Account": "AW298252", "Item": { "Quantity": 12 } }, { "Order": { "Number": "SO43661", "Date": "2011-06-01T00:00:00" }, "Account": "AW73565", "Item": { "Quantity": 3 } } ] }

The same sql but with AUTO mode:

select Number as [Order.Number], Date as [Order.Date], Customer as [Account], Quantity as [Item.Quantity] from SalesReport FOR JSON AUTO, ROOT('Orders') -- auto mode

The result will be:

{ "Orders": [ { "Order.Number": "SO436592", "Order.Date": "2011-05-31T00:00:00", "Account": "AW298252", "Item.Quantity": 12 }, { "Order.Number": "SO43661", "Order.Date": "2011-06-01T00:00:00", "Account": "AW73565", "Item.Quantity": 3 } ] }

When you join tables, columns in the first table are generated as properties of the root object. Columns in the second table are generated as properties of a nested object. The table name or alias of the second table is used as the name of the nested array. For example:

select 123 as Id, 'Jason' as FirstName, 'json@gmail.com' as Email into Person select 123 as PersonId, '1/10 High street' as HomeAddress into Address select * from Person join Address on Id = PersonId FOR JSON AUTO, Root('Users')

The result will be:

{ "Users": [ { "Id": 123, "FirstName": "Jason", "Email": "json@gmail.com", "Address": [ { "PersonId": 123, "HomeAddress": "1\/10 High street" } ] } ] } More on Arrays

We can use index to locate the item in an array. Actually when we use OPEN_JSON to read the array in a JSON string, it will output some other informations:

select Order2s.* from SalesReportJson cross apply openjson(Orders) as Order2s

The result will be:

key value type 0 { “Order”: { “Number”:”SO43659”, “Date”:”2011-05-31T00:00:00” }, “AccountNumber”:”AW29825”, “Item”: { “Price”:100.0, “Quantity”:1 } } 5 1 { “Order”: { “Number”:”SO43661”, “Date”:”2011-06-01T00:00:00” }, “AccountNumber”:”AW73565”, “Item”: { “Price”:2024.9940, “Quantity”:3 } } 5

The first column is key , which is the index of each item in the array, the column type indicate it’s an object value. with the key , we can do some conditional modification to some items in an array.