Book Image

SQL Server 2016 Developer's Guide

By : Miloš Radivojević, Dejan Sarka, William Durkin
Book Image

SQL Server 2016 Developer's Guide

By: Miloš Radivojević, Dejan Sarka, William Durkin

Overview of this book

Microsoft SQL Server 2016 is considered the biggest leap in the data platform history of the Microsoft, in the ongoing era of Big Data and data science. This book introduces you to the new features of SQL Server 2016 that will open a completely new set of possibilities for you as a developer. It prepares you for the more advanced topics by starting with a quick introduction to SQL Server 2016's new features and a recapitulation of the possibilities you may have already explored with previous versions of SQL Server. The next part introduces you to small delights in the Transact-SQL language and then switches to a completely new technology inside SQL Server - JSON support. We also take a look at the Stretch database, security enhancements, and temporal tables. The last chapters concentrate on implementing advanced topics, including Query Store, column store indexes, and In-Memory OLTP. You will finally be introduced to R and learn how to use the R language with Transact-SQL for data exploration and analysis. By the end of this book, you will have the required information to design efficient, high-performance database applications without any hassle.
Table of Contents (21 chapters)
SQL Server 2016 Developer's Guide
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
12
In-Memory OLTP Improvements in SQL Server 2016

Extracting values from a JSON text


As mentioned earlier in this chapter, JSON has four primitive types (string, number, Boolean, and null) and two complex (structure) types: object and array. SQL Server 2016 offers two functions to extract values from a JSON text:

  • JSON_VALUE: This is used to extract values of primitive data types

  • JSON_QUERY: This is used to extract a JSON fragment or to get a complex value (object or array)

JSON_VALUE

The JSON_VALUE function extracts a scalar value from a JSON string. It accepts two input arguments:

  • Expression: This is  JSON text in the Unicode format.

  • Path: This is an optional argument. It is a JSON path expression and you can use it to specify a fragment of the input expression.

The return type of the function is nvarchar(4000), with the same collation as in the input expression. If the extracted value is longer than 4,000 characters, the function returns NULL provided the path is in lax mode or an error message in the case of strict mode.

If either the expression...