Hi, Community!

This article is an overview of SQLAlchemy, so let's begin!

SQLAlchemy is the Python SQL toolkit that serves as a bridge between your Python code and the relational database system of your choice. Created by Michael Bayer, it is currently available as an open-source library under the MIT License. SQLAlchemy supports a wide range of database systems, including PostgreSQL, MySQL, SQLite, Oracle, and Microsoft SQL Server, making it versatile and adaptable to different project requirements.

The SQLAlchemy SQL Toolkit and Object Relational Mapper from a comprehensive set of tools for working with databases and Python. It has several distinct areas of functionality which you can use individually or in various combinations. The major components are illustrated below, with component dependencies organized into layers:

_images/sqla_arch_small.png

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Article
· Jan 11, 2019 4m read
SQL Performance Resources

There are three things most important to any SQL performance conversation: Indices, TuneTable, and Show Plan. The attached PDFs includes historical presentations on these topics that cover the basics of these 3 things in one place. Our documentation provides more detail on these and other SQL Performance topics in the links below. The eLearning options reinforces several of these topics. In addition, there are several Developer Community articles which touch on SQL performance, and those relevant links are also listed.

There is a fair amount of repetition in the information listed below. The most important aspects of SQL performance to consider are:

  1. The types of indices available
  2. Using one index type over another
  3. The information TuneTable gathers for a table and what it means to the Optimizer
  4. How to read a Show Plan to better understand if a query is good or bad
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Earlier in this series, we've presented four different demo applications for iKnow, illustrating how its unique bottom-up approach allows users to explore the concepts and context of their unstructured data and then leverage these insights to implement real-world use cases. We started small and simple with core exploration through the Knowledge Portal, then organized our records according to content with the Set Analysis Demo, organized our domain knowledge using the Dictionary Builder Demo and finally build complex rules to extract nontrivial patterns from text with the Rules Builder Demo.

This time, we'll dive into a different area of the iKnow feature set: iFind. Where iKnow's core APIs are all about exploration and leveraging those results programmatically in applications and analytics, iFind is focused specifically on search scenarios in a pure SQL context. We'll be presenting a simple search portal implemented in Zen that showcases iFind's main features.

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Hey developers!

Sometimes we need to insert or refer to the data of classes directly in globals.

And maybe a lot of you expect that data structure of global with records is:

^Sample.Person(Id)=$listbuild("",col1,col2,...,coln).

And this article is a heads up, that this is not always true, don't expect it as granted!

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Hi folks!

Sometimes we need to import data into InterSystems IRIS from CSV. It can be done e.g. via csvgen tool that generates a class and imports all the data into it.

But what if you already have your own class and want to import data from CSV into your existing table?

There are numerous ways to do that but you can use csvgen (or csvgen-ui) again! I prepared and and example and happy to share. Here we go!

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What is Unstructured Data?
Unstructured data refers to information lacking a predefined data model or organization. In contrast to structured data found in databases with clear structures (e.g., tables and fields), unstructured data lacks a fixed schema. This type of data includes text, images, videos, audio files, social media posts, emails, and more.

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Article
· Jul 18, 2017 2m read
Old/New Dynamic SQL Cheat Sheet

The newer dynamic SQL classes (%SQL.Statement and %StatementResult) perform better than %ResultSet, but I did not adopt them for some time because I had learned how to use %ResultSet. Finally, I made a cheat sheet, which I find useful when writing new code or rewriting old code. I thought other people might find it useful.

First, here is a somewhat more verbose adaptation of my cheat sheet:

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An interesting pattern around unique indices came up recently (in internal discussion re: isc.rest) and I'd like to highlight it for the community.

As a motivating use case: suppose you have a class representing a tree, where each node also has a name, and we want nodes to be unique by name and parent node. We want each root node to have a unique name too. A natural implementation would be:

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So I know it's been a while, and I hate to let my adoring fans down... just not enough to actually start writing again. But the wait is over and I'm back! Now bask in my beautiful ginger words!

For this series, I am going to look at some common problems we see in the WRC and discuss some common solutions. Of course, even if you find a solution here, you are always welcome to call in and expression you gratitude, or just hear my voice!

This week's common problem: "My query returns no data."

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Article
· Jul 26, 2019 3m read
Dynamic SQL to Dynamic Object

Hello community! I have to work with queries using all kinds of methods like embedded sql and class queries. But my favorite is dynamic sql, simply because of how easy it is to manipulate them at runtime. The downside to writing a lot of these is the maintenance of the code and interacting with the output in a meaningful way.

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Hi folks!

Sometimes when we develop a mockup or PoC there is a need for a simple interface that will provide data in IRIS in JSON against SQL queries.

And recently I contributed a simple module that does exactly that:

accepts SQL string and returns the JSON.

How to install? Just call:

zpm "install sql-rest"

If you install it in a namespace X it will setup a /sql endpoint to your system that will accept POST requests with SQL string and will return the result for you for the data available in the namespace X.

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Hello Community,

SQL language remains the most practical way to retrieve information stored in a database.

The JSON format is very often used in data exchange.

It is therefore common to seek to obtain data in JSON format from SQL queries.

Below you will find simple examples that can help you meet this need using ObjectScript and Python code.

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Article
· Jul 7, 2017 19m read
Indexing of non-atomic attributes

Quotes (1NF/2NF/3NF)ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be
  • atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
  • non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

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Article
· Mar 29, 2023 1m read
Named Parameter In SQL with Python

Quick Tips: Total Productive Maintenance

Named parameters can be achieved with SQLAlchemy :

from sqlalchemy import create_engine, text,types,engine

_engine = create_engine('iris+emb:///')

with _engine.connect() as conn:
    rs = conn.execute(text("select :some_private_name"), {"some_private_name": 1})
    print(rs.all())

or with native api

from sqlalchemy import create_engine, text,types,engine

# set URL for SQLAlchemy
url = engine.url.URL.create('iris', username='SuperUser', password='SYS', host='localhost', port=33782, database='FHIRSERVER')

_engine = create_engine(url)

with _engine.connect() as conn:
    rs = conn.execute(text("select :some_private_name"), {"some_private_name": 1})
    print(rs.all())

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The last days I've work with the great new feature: LOAD DATA With this post I would like to share my first experiences with you. The following points do not contain any order or other evaluation. These are only things that I noticed when using the LOAD DATA command. It should also be noted that these points are based on the IRIS Version 2021.2.0.617 which is a preview release. So it may be that my observations do not apply to newer IRIS versions.

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Hi Developers!

There is a recent update came for developer community images of InterSystems IRIS and IRIS For Health.

This release comes with Environment variables support.

Currently 3 variables are supported:

  • IRIS_USERNAME=user to create
  • IRIS_PASSWORD=with password
  • IRIS_NAMESPACE=create namespace if doesn't exist

Here is what you can do - see below.

Start iris with your username and password created:

docker run --rm --name iris-sql -d -p 9091:1972 -p 9092:52773  -e IRIS_PASSWORD=demo -e IRIS_USERNAME=demo intersystemsdc/iris-community

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Article
· Apr 19, 2023 2m read
Apache Superset now with IRIS

Apache Superset is a modern data exploration and data visualization platform. Superset can replace or augment proprietary business intelligence tools for many teams. Superset integrates well with a variety of data sources.

And now it is possible to use with InterSystems IRIS as well.

An online demo is available and it uses IRIS Cloud SQL as a data source.

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Article
· May 25, 2017 2m read
The Interns are Coming!

The Data Platforms department here at InterSystems is gearing up for this year's crop of interns, and I for one am very excited to meet them all next week!

We've got folks from top technical colleges with diverse specialties from hard core engineers to pure computer scientists to mathematicians to business professionals. They come from countries around the world like Vietnam, China, and Finland and they all come with impressive backgrounds. We're sure they will do very well this summer.

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Article
· Jan 28, 2022 2m read
Embedded SQL Bug and Workaround

We recently encountered an Embedded SQL issue while upgrading to IRIS 2021.1, and thought the issue and workaround might be interesting to share.

Key takeaway: Host variables in an ORDER BY clause of an embedded SQL query that is inside of a method don't work as expected. IRIS versions starting with 2020.1 are affected. As a workaround, add the host variable to the Method's PublicList list and "new" them so the embedded query has access to them.

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What is %SQLRESTRICT

%SQLRESTRICT is a special %FILTER clause for use in MDX queries in InterSystems IRIS Business Intelligence. Since this function begins with %, it means this is a special MDX extension created by InterSystems. It allows users to insert an SQL statement that will be used to restrict the returned records in the MDX Result Set. This SQL statement must return a set of Source Record IDs to limit the results by. Please see the documentation for more information.

Why is this useful?

This is useful because there are often times users want to restrict the results in their MDX Result Set based on information that is not in their cubes. It may be the case that this information may not make sense to be in the cube. Other times this can be useful when there is a large set of values you want to restrict. As mentioned before, this is not a standard MDX function, it was created by InterSystems to handle cases were queries were not performing well or cases that were not easily solved by existing functions.

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