Book Image

Mastering SQL Server 2017

By : Miloš Radivojević, Dejan Sarka, William Durkin, Christian Cote, Matija Lah
Book Image

Mastering SQL Server 2017

By: Miloš Radivojević, Dejan Sarka, William Durkin, Christian Cote, Matija Lah

Overview of this book

Microsoft SQL Server 2017 uses the power of R and Python for machine learning and containerization-based deployment on Windows and Linux. By learning how to use the features of SQL Server 2017 effectively, you can build scalable apps and easily perform data integration and transformation. You’ll start by brushing up on the features of SQL Server 2017. This Learning Path will then demonstrate how you can use Query Store, columnstore indexes, and In-Memory OLTP in your apps. You'll also learn to integrate Python code in SQL Server and graph database implementations for development and testing. Next, you'll get up to speed with designing and building SQL Server Integration Services (SSIS) data warehouse packages using SQL server data tools. Toward the concluding chapters, you’ll discover how to develop SSIS packages designed to maintain a data warehouse using the data flow and other control flow tasks. By the end of this Learning Path, you'll be equipped with the skills you need to design efficient, high-performance database applications with confidence. This Learning Path includes content from the following Packt books: SQL Server 2017 Developer's Guide by Miloš Radivojevi?, Dejan Sarka, et. al SQL Server 2017 Integration Services Cookbook by Christian Cote, Dejan Sarka, et. al
Table of Contents (20 chapters)
Title Page
Free Chapter
1
Introduction to SQL Server 2017

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...