#SQL

I have two classes:

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

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.

Temporary tables are tables available for a current process only (and destroyed when process ends).

What are you approaches to creating temporary tables?

Good Morning,

I have this question for a long time. When I make an insert by SQL from an external application in the fields of type %String, if they are empty, it writes the character $c(0) in the global.

Is there a way so that if an Insert is received in a field of type% String with null value instead of the $ c (0) it leaves it empty?:

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 <...>".

How to convert SQL persistent classes to JSON output - I have tried 1 option but appears to be very lengthy process.

I have many other SQL storage's defined and have to expose them as well to JSON. Can anyone please suggest a better approach.

My column names usually match with my Json properties.

My User.TestClass is the class with GetJsonList() as my method to return /output JSON formatted data.

The Code tried and SQL storage structure are as follows -

In writing some code on:

Cache for Windows (x86-64) 2015.1 (Build 429U) Fri Feb 13 2015 14:37:23 EST

I noticed an unexpected "ROLLFAIL" error when a Unique Index fail was generated in a %Save() call.

The object SHOULD fail to save, since the Unique criteria is not met, but I didn't expect to see a ROLLFAIL error as the "Last Error".

When running the following class code:

Greetings,

I am working on the first of many triggers which will have identical code upon row insertion or update of a single column. According to the document I should be able to define a multiple-event trigger using Cache SQL/DDL.

Here is a link to the current CREATE TRIGGER documentation. Within the description section is the following paragraph:

Hi guys,

My client has a requirement to add a column of random numbers to the query result.

I wrote a function as below:

Class Utils.SqlUtility Extends %RegisteredObject
{

ClassMethod GetSomeNumber(intInput As %Integer) As %Integer [ SqlName = GetNumber, SqlProc ]
{
Return $R(intInput)
}

}

But in the returned sql result, every row share the same value, as below,

SELECT Utils.GetNumber('456'),
ID, Citizenship, DOB, FirstName, Gender, IDNumber, LastName, PatientNumber, PhoneNumber
FROM CDR.Patient

Hi all

I'm struggling to insert into a table, and it is baffling me. The insert statement is now very simple (I was using a complex INSERT SELECT statement but I'm trying to narrow down the problem).

Insert statement:

In the vast and varied SQL database market, InterSystems IRIS stands out as a platform that goes way beyond just SQL, offering a seamless multimodel experience and supporting a rich set of development paradigms. Especially the advanced Object-Relational engine has helped organizations use the best-fit development approach for each facet of their data-intensive workloads, for example ingesting data through Objects and simultaneously querying it through SQL. Persistent Classes correspond to SQL tables, their properties to table columns and business logic is easily accessed using User-Defined Functions or Stored Procedures. In this article, we'll zoom in on a little bit of the magic just below the surface, and discuss how it may affect your development and deployment practices. This is an area of the product where we have plans to evolve and improve, so please don't hesitate to share your views and experiences using the comments section below.

Hi Community!

There are two general ways to execute arbitrary SQL in serverside ObjectScript code: EmbeddedSQL and ObjectScript SQL a.k.a. Dynamic SQL.

E.g. if we want to get the value of the property of instance with a certain ID using SQL we can do:

&sql(SELECT Name INTO :name FROM Sample.Person WHERE ID=1)

write name

Same result with %SQL.Statement:

set rs=##class(%SQL.Statement).%ExecDirect(,"SELECT Name as name FROM Sample.Person where ID=1")
  do rs.%Next()
  write rs.name

Hi!

Is there a method in a persistent class that can return the current number of records/persistent objects in it?