#SQL

Last week, we announced the InterSystems IRIS Data Platform, our new and comprehensive platform for all your data endeavours, whether transactional, analytics or both. We've included many of the features our customers know and loved from Caché and Ensemble, but in this article we'll shed a little more light on one of the new capabilities of the platform: SQL Sharding, a powerful new feature in our scalability story.

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."

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.

Overview

Encryption of sensitive data becomes more and more important for applications. For example patient names, SSN, address-data or credit card-numbers etc..

Cache supports different flavors of encryption. Block-level database encryption and data-element encryption. The block-level database encryption protects an entire database. The decryption/encryption is done when a block is written/read to or from the database and has very little impact on the performance.

With data-element encryption only certain data-fields are encrypted. Fields that contain sensitive data like patient data or credit-card numbers. Data-element encryption is also useful if a re-encryption is required periodically. With data-element encryption it is the responsibility of the application to encrypt/decrypt the data.

Both encryption methods leverage the managed key encryption infrastructure of Caché.

The following article describes a sample use-case where data-element encryption is used to encrypt person data.

But what if you have hundreds of thousands of records with an encrypted datafield and you have the need to search that field? Decryption of the field-values prior to the search is not an option. What about indices?

This article describes a possible solution and develops step-by-step a small example how you can use SQL and indices to search encrypted fields.

It is often necessary to sort the results of a query on a string field containing a combination of alphabetic and numeric characters. In cases like this the default string collation may not always return the data in the expected sequence.

An example of this may be where a select from Samples.Person should order the results by the street address, but firstly ordered by the street number part as numeric, and then by the street name.

The default query will return the results as follows:

This is a translation of the following article. Thanks [@Evgeny Shvarov] for the help in translation.

Someone posted a question on DC asking whether it was possible to determine access rights for a particular table row always at runtime, and if it was, how could one do that?
Answer: it is possible and it’s not hard at all.

I am experimenting with Relationships, both Parent to Child and One to Many.

I have done some SQL look-ups and have searched through the documentation, however not in a lot detail, but wonder if there are more and better ways to access both sides of Relationships through SQL?

Thank you in advance for any help provided.

Hi, folks!

When you deploy DeepSee solutions you often do not want grant a User %All Role to work with a particular Dashboard.

Consider a Dashboard 'Dash' with a few widgets where listings are being used.

If you manage a Role to get access to the Dash you need to grant access to %DB_DBNAME resource to have a database access, grant access to a Dashboard resource (if any) and ... grant SELECT accesses to all the tables involved in SQL queries being used in all the listings of widgets.

Hi!

I have a global-mapped class that I want to add a transient property through (or at least, not stored on the database). This property is the sum total of various charge classes that are linked to the class via child relationships.

I want this new transient property to be visible at least via SQL.

Hi,

My doubt is about the SQL Query in Caché:

I don't want to take all results from the table and orgainze them manually, for example: I have a table with 50 records, but I only want to select 10 records, being from tenth until the twentieth and this without knowing their IDs.

So, how can I do this, without losing performance, there is any way?

Hello, we have a few hundreds of triggers to port from Oracle to Cachè for a migration project, and many of them have to change (for example, normalize a value, null it, etc) the value which is being inserted.

The documentation says "You cannot set {fieldname*N} in trigger code." , so we're unlucky.

Is there a good workaround for this ?

SqlComputeOnChange doesn't seem the best way, but I'm not totally sure: for example normalization and validation could have a better place somewhere else than a trigger.

I am currently working on a issue with WRC on one of my Inbound SQL Adapters not returning all the records it should be. If I looked at the count of the records in Ensemble and compare it to that of a Microsoft SQL View, Ensemble seems to be off by a few records here and there. I am using a full dynamic select statement in my settings of the adapter.

SELECT Text, PhysicianLastName, PhysicianFirstName, PhysicianAddress1, PhysicianAddress2, PhysicianCity,

Any suggestions on the most efficient way to convert yyyymmdd string to mm/dd/yyyy?

hi

I execute sql like this: select * from DHC_PatBillDetails where PBD_PBO_ParRef>='2046121'

error message:

but the sql: select * from DHC_PatBillDetails where PBD_PBO_ParRef='2046121' can be executed successfully

why?