Tabular data stream sql server how to#
Tabular data stream sql server full#

OPENJson function can’t have certain deprecated datatypes in its ‘explicit schema’ syntax.There are some interesting things we have to take into account in reading data into a table. We need to provide a way of reading and writing these files. For this article, we’ll just stick to tables, rather than the broader topic of results of queries of maybe several tables. We need to consider both the Data and the Schema. Transferring Data as an Array of Objects. It is probably the simplest because it represents the way used by FOR JSON queries. We will, for this article, stick to the most common way of rendering tabular data, as an array of objects. I’ll explain more about this later, but first, we need to be confident that we are able to use JSON to reliably copy a table from one server to another. CSV can only be used effectively if both ends of the conversation know what every column means based on the name of the file and the header row, but with JSON, we don’t have to be so restrictive, because we can send a schema with the data. This goes some small way towards portability, but with JSON, we have the opportunity to associate far more of the metadata or a schema with the data. The header line is in the same format as normal record lines. The CSV standard allows the first ‘header’ line to display the name of the column rather than the first line of data. This suits me, because they lose interest in accessing the base tables. They are content just to send and receive data in this format. However, there are other benefits, because nowadays the front-end developers understand, and are happy with, JSON. If one can send the metadata in a way that is useful enough to allow creating a table successfully with it, then it is worth the effort. At last, you can distinguish between a blank string and a null one. No matter how you choose to use it, you’ll notice something useful if you are accustomed to CSV: JSON supports null values as well as the bit values true and false. However, raw JSON is good-natured enough not to object if you want to use it that way. JSON wasn’t originally intended for relational data which is constrained by a schema or where the order of data within a row is invariant, as it is in CSV. Why Use JSON at All When We Have Good Old CSV? For me, the attraction is that I can avoid having to invent a way of transferring the metadata of file-based JSON Data. You can even generate JSON Schemas from NET types.

Tabular data stream sql server full#

NewtonSoft provides an excellent version of JSON that has full JSON Schema support and an online JSON Validator. MongoDB, for example, can use JSON Schema to validate a collection. It also provides a standard way of providing metadata for other purposes beyond JSON-based storage. JSON Schema allows you to validate the contents of a JSON file and to specify constraints. If you are interested in checking out JSON to see if it works for you, I’ll be showing you how you can transfer both the data and the metadata or schema, using JSON with JSON Schema, with standard conventions, and avoid the quirks in the SQL Server implementation.

We’ll test it out by attempting this on AdventureWorks.

Tabular data stream sql server how to#

I will be showing how to save SQL Server tables as JSON files that include the metadata and import them into SQL Server. Sure, ODBC actually does this, but it is not a file-based transfer. It makes it possible to transfer tables between different systems. In other words, it transfers the metadata as well as the data. I have long had a dream of transferring data in such a way that the recipient has enough information to create a table automatically to receive the data. Now that JSON is acquiring a standard for JSON Schema which is being adopted widely, is it time to reconsider? With network speeds a thousand times faster than when SQL Server was first created, are we still bound to the traditional ways of transferring data? Should we consider other ways? Secondly, TDS (Tabular Data Stream) is a very efficient application-layer protocol finally, it is bullet-proof in its reliability. Why do we stick to ODBC and TDS to send and receive tables? Well, it is for three reasons the conventions within ODBC quietly send the metadata, or ‘data about the data,’ along with the data itself. There is a rich infrastructure of both standards, resources, and components that make this easy. SQL server has at last provided enough functionality to allow us to use JSON to transmit data within applications and between applications and receive data from web services and network sources. For transmitting and transferring data, JSON should be part of your toolkit because it is so widely used and supported. When you use JSON to store data, you are generally forced down the route of using a special-purpose database, though SQL Server is happy to accommodate JSON as an NVARCHAR(MAX). JSON has two distinct uses, to transmit data and to store it.