Format Nested JSON Output with PATH Mode#

To maintain full control over the output of the FOR JSON clause, specify the PATH option.

PATH mode lets you create wrapper objects and nest complex properties. The results are formatted as an array of JSON objects.

The alternative is to use the AUTO option to format the output automatically based on the structure of the SELECT statement.

  • For more info about the AUTO option, see Format JSON Output Automatically with AUTO Mode.

  • For an overview of both options, see Format Query Results as JSON with FOR JSON.

Here are some examples of the FOR JSON clause with the PATH option.

Example - Dot-separated column names#

The following query formats the first five rows from the AdventureWorks Person table as JSON.

The FOR JSON PATH clause uses the column alias or column name to determine the key name in the JSON output. If an alias contains dots, the PATH option creates nested objects.

SELECT TOP 5
       BusinessEntityID As Id,
       FirstName, LastName,
       Title As 'Info.Title',
       MiddleName As 'Info.MiddleName'
  FROM Person.Person
   FOR JSON PATH

Result:

[{
    "Id": 1,
    "FirstName": "Ken",
    "LastName": "Sanchez",
    "Info": {
        "MiddleName": "J"
    }
}, {
    "Id": 2,
    "FirstName": "Terri",
    "LastName": "Duffy",
    "Info": {
        "MiddleName": "Lee"
    }
}, {
    "Id": 3,
    "FirstName": "Roberto",
    "LastName": "Tamburello"
}, {
    "Id": 4,
    "FirstName": "Rob",
    "LastName": "Walters"
}, {
    "Id": 5,
    "FirstName": "Gail",
    "LastName": "Erickson",
    "Info": {
        "Title": "Ms.",
        "MiddleName": "A"
    }
}]

Example - Multiple tables#

If you reference more than one table in a query, FOR JSON PATH nests each column using its alias. The following query creates one JSON object per (OrderHeader, OrderDetails) pair joined in the query.

SELECT TOP 2
       H.SalesOrderNumber AS 'Order.Number',
       H.OrderDate AS 'Order.Date',
       D.UnitPrice AS 'Product.Price',
       D.OrderQty AS 'Product.Quantity'
  FROM Sales.SalesOrderHeader H
 INNER JOIN Sales.SalesOrderDetail D
    ON H.SalesOrderID = D.SalesOrderID
   FOR JSON PATH

Result:

[{
    "Order": {
        "Number": "SO43659",
        "Date": "2011-05-31T00:00:00"
    },
    "Product": {
        "Price": 2024.9940,
        "Quantity": 1
    }
}, {
    "Order": {
        "Number": "SO43659"
    },
    "Product": {
        "Price": 2024.9940
    }
}]

See also#