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#SQL

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SQL is a standard language for storing, manipulating and retrieving data in relational databases.

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When using the JSON_OBJECT() function in Caché SQL on a %String property that contains JSON syntax, it converts the %String into a JSON object instead of escaping it as a string literal. How can I prevent this? (without ridiculous hacks like "add a space to the beginning of the value" as we don't always know which properties will contain these values and I certainly don't want to have to check for nulls and add/remove a space every single place this value is used in the application)

I don't want these strings automatically marshalled into JSON objects.

For example:

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Let's say I have this property:

Property FavoriteColors As List Of %String;

I heed to convert it to JSON using SQL or at least without object access (so direct global access).

What's the fastest way to do that?

I thought about JSON_ARRAY and JSON_ARRAYAGG sql functions but they don't do that.

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Question
· Oct 30, 2018
ID vs %ID in tables

What is the difference between %ID and ID in a database table? Both seem to reference the same column labelled ID.

For context, I am trying to create a viewer class for an existing persistent class.

Let us call the persistent class A, with SqlTableName = OldA.

The viewer class will be B with SqlTableName = A and ViewQuery = {select %ID, <other fields> from <some other class with the same fields as A>}

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Question
· Feb 9, 2018
SQL prepare error

I'm trying to learn how To use SQL in CACHE, so I hope I don't bore you with "Dumb" questions....

I'm getting "ERROR #6022: Gateway failed" message following this line of code. 

s sc=gc.Prepare(hstmt,pQuery)

This line of code comes from an example I found in the documentation. pQuery is the "Select" statement setting up the variables and tables I'm trying to pull information from.

What does that error indicate?

Thank you.

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Question
· Jun 22, 2017
Hash values of columns

I try to find a function, which generates hash values of columns. In MS SQL Server I can use

select hashbytes('sha2_256', my_column) ...

to create hash values of my_column. Is it possible to use such things in Caché?

Thank you
André

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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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Question
· Oct 2, 2018
%NOLOCK in insert query

I would like to know , if its safe to use %NOLOCK in insert query while doing some parallel processing in Ensemble. We will have pool size of more than 1 for a business process. The business process does an entry in internal meta data table , which will be used for some internal reporting. The same row might get updated by some other process later point of time. i could not produce any error or any issues . Looking forward to hear some opinion on this.

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We are creating a package (written in Caché Object Script) that will provide access to an external DB (MySQL). Because applications that use our package will be run from machines with various, potentially unexpected, operating systems, we’d like to establish a connection to the external DB without using DSNs (we’ve heard that setting up DSNs on certain non-Windows machines can be cumbersome and problematic).

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Let me introduce my new project, which is irissqlcli, REPL (Read-Eval-Print Loop) for InterSystems IRIS SQL

  • Syntax Highlighting
  • Suggestions (tables, functions)
  • 20+ output formats
  • stdin support
  • Output to files

Install it with pip

pip install irissqlcli

Or run with docker

docker run -it caretdev/irissqlcli irissqlcli iris://_SYSTEM:SYS@host.docker.internal:1972/USER

Connect to IRIS

$ irissqlcli iris://_SYSTEM@localhost:1972/USER -W
Password for _SYSTEM:
Server:  InterSystems IRIS Version 2022.3.0.606 xDBC Protocol Version 65
Version: 0.1.0
[SQL]_SYSTEM@localhost:USER> select $ZVERSION
+---------------------------------------------------------------------------------------------------------+
| Expression_1                                                                                            |
+---------------------------------------------------------------------------------------------------------+
| IRIS for UNIX (Ubuntu Server LTS for ARM64 Containers) 2022.3 (Build 606U) Mon Jan 30 2023 09:05:12 EST |
+---------------------------------------------------------------------------------------------------------+
1 row in set
Time: 0.063s
[SQL]_SYSTEM@localhost:USER> help
+----------+-------------------+------------------------------------------------------------+
| Command  | Shortcut          | Description                                                |
+----------+-------------------+------------------------------------------------------------+
| .exit    | \q                | Exit.                                                      |
| .mode    | \T                | Change the table format used to output results.            |
| .once    | \o [-o] filename  | Append next result to an output file (overwrite using -o). |
| .schemas | \ds               | List schemas.                                              |
| .tables  | \dt [schema]      | List tables.                                               |
| \e       | \e                | Edit command with editor (uses $EDITOR).                   |
| help     | \?                | Show this help.                                            |
| nopager  | \n                | Disable pager, print to stdout.                            |
| notee    | notee             | Stop writing results to an output file.                    |
| pager    | \P [command]      | Set PAGER. Print the query results via PAGER.              |
| prompt   | \R                | Change prompt format.                                      |
| quit     | \q                | Quit.                                                      |
| tee      | tee [-o] filename | Append all results to an output file (overwrite using -o). |
+----------+-------------------+------------------------------------------------------------+
Time: 0.012s
[SQL]_SYSTEM@localhost:USER>

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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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I have a MySQL server with "posts" table.

I also have a Caché server with "downloadedposts" table.

They are connected from Caché to MySQL via SQL Gateway

I want to keep Caché table synced with MySQL one (MySQL "posts" table is a master copy), so periodically Caché queries MySQL server and downloads data. So far so good, and if a record appears or changes in MySQL table, Caché downloads the changes.

The problem I'm encountering is that sometimes rows would be deleted from MySQL "posts" table.

How do I synchronize deletions?

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Python has become the most used programming language in the world (source: https://www.tiobe.com/tiobe-index/) and SQL continues to lead the way as a database language. Wouldn't it be great for Python and SQL to work together to deliver new functionality that SQL alone cannot? After all, Python has more than 380,000 published libraries (source: https://pypi.org/) with very interesting capabilities to extend your SQL queries within Python.

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Article
· Sep 18, 2023 7m read
Vectors support, well almost

Nowadays so much noise around LLM, AI, and so on. Vector databases are kind of a part of it, and already many different realizations for the support in the world outside of IRIS.

Why Vector?

  • Similarity Search: Vectors allow for efficient similarity search, such as finding the most similar items or documents in a dataset. Traditional relational databases are designed for exact match searches, which are not suitable for tasks like image or text similarity search.
  • Flexibility: Vector representations are versatile and can be derived from various data types, such as text (via embeddings like Word2Vec, BERT), images (via deep learning models), and more.
  • Cross-Modal Searches: Vectors enable searching across different data modalities. For instance, given a vector representation of an image, one can search for similar images or related texts in a multimodal database.

And many other reasons.

So, for this pyhon contest, I decided to try to implement this support. And unfortunately I did not manage to finish it in time, below I'll explain why.

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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 all,

I am new in Cache. I have to update a record with a long text field, for that, I am using ODBC but the issue is that it is returning an error when I execute the ODBC SQL statement because the field contains some commas, colon, double quotes, single quotes, and CR LF characters.

There is a way to escape this chars? I have seen I can save the field when I replace the single quotes with a double single quote (it's -> it''s) but I can not save the information when the field contains double quote chars. What about the other chars?

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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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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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In this article you will have access to the curated base of articles from the InterSystems Developer Community of the most relevant topics to learning InterSystems IRIS. Find top published articles ranked by Machine Learning, Embedded Python, JSON, API and REST Applications, Manage and Configure InterSystems Environments, Docker and Cloud, VSCode, SQL, Analytics/BI, Globals, Security, DevOps, Interoperability, Native API. Learn and Enjoy!

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Question
· Oct 11, 2018
Double Quotes

Hi,

I am trying to have the output of a field in sql have double quotes around them. The script is in Studio and I am accessing It through a task.

I have tried """"tect"""" and others...Please help

Aloha

Lou

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