Example 5 – Path ModeĪs mentioned, you also have the option of specifying the path mode. In this example I used JSON_VALUE() to extract various scalar values, but I also used JSON_QUERY() to return a whole array (which JSON_VALUE() can’t do). "Hobbies": ["Eating", "Sleeping", "Base AS AS AS 'Last Hobby' Here’s an example: DECLARE NVARCHAR(4000)
However, there’s nothing to stop you combining both functions within a query to return data at various levels of granularity. If you want to return a scalar value, use the JSON_VALUE() function instead. The JSON_QUERY() function is not designed to return scalar values. This assumes that the JSON document is stored in a column called Document, which is in a table called Json_Documents. JSON_QUERY(Document,'$.Cities') AS 'City 1' If we were to put the data from the previous example into a database, we could rewrite the query as follows: SELECT Here’s what happens when we do that using the same data from the previous examples: DECLARE NVARCHAR(4000) The second argument is optional, so if you omit it, the whole JSON document is returned. Like this: DECLARE NVARCHAR(4000)Įxample 2 – Return the Whole JSON Expression I could access the second item by using Cities. In this case I use Cities to reference the first item in the array (JSON arrays use zero-based numbering). Once I’ve done this, I run a query against that array. In this example, I first declare and set a variable called I then assign an array to this variable. Here’s an example to demonstrate basic usage of the JSON_QUERY() function. The path mode (if supplied) comes before the dollar sign. This value determines what happens in the event the supplied path is invalid. This optional path mode can be a value of either lax or strict. The path argument (if supplied) can include an optional path mode component. The path argument is optional (if you don’t provide it, the whole JSON document is returned). Where expression is the JSON string expression, and path is the object or array that you want to extract from that expression. The syntax goes like this: JSON_QUERY ( expression ) You can also provide a second (optional) argument to specify the object or array to extract. To use this function, you provide the JSON expression as an argument. JavaScript provides JSON.When using JSON with SQL Server, you can use the JSON_QUERY() function to extract an object or an array from a JSON string.
#Json query tutorial code
Sometimes JavaScript object or value from your code need to be transferred to the server during an Ajax communication. Rowlingĭocument.write(obj + "") // Prints: Harry Potterĭocument.write(obj) // Prints: $20.32 Printing all the values from the resulting objectĭocument.write(obj + "") // Prints: J. Define recursive function to print nested values "name": "Harry Potter and the Goblet of Fire", A JSON object may look like this:Įxample Try this code » /* Storing multi-line JSON string in a JS variable Strings must be enclosed in double quotes " and can contain escape characters such as \n, \t and \. In JSON, property names or keys are always strings, while the value can be a string, number, true or false, null or even an object or an array. Array: This is defined as an ordered list of values.Multiple key/value pairs are separated by a comma.
Each object begins with a left curly bracket.
Like XML, JSON is also a text-based format that's easy to write and easy to understand for both humans and computers, but unlike XML, JSON data structures occupy less bandwidth than their XML versions. JSON is extremely lightweight data-interchange format for data exchange between server and client which is quick and easy to parse and generate. JSON stands for Java Script Object Notation.
#Json query tutorial how to
In this tutorial you will learn how to encode and decode JSON data in JavaScript.