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#SQL

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

I try to create a column with computeonchange.

Its works with CREATE TABLE sql command, but if i use ALTER TABLE ADD COLUMN sql command this computeonchange doesn't works.

any reason why?

example:

CREATE TABLE MyStudents ( Name VARCHAR(16) NOT NULL, surname VARCHAR(16))

alter table MyStudents add column fullname Varchar(50) COMPUTECODE { SET {fullname}={Name}_ "?" _{surname}} COMPUTEONCHANGE (Name,surname)

insert into SQLUser.MyStudents (Name, surname) values ('name1',null)

update MyStudents set name = 'name' where name = 'name1'

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Greetings community. I would like to know how to migrate a BD in production to a local environment. When I have a system in production (BD Sql Server) what we do is mount a local copy to do the analysis with the data and not occupy resources of the system in production. My question is: How do you do it with Intersystems technology?

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Question
· Dec 26, 2019
Performant index on date field

Is there a way to get a good performing index on a date field? I have tried various date property indexes and the query plan is always in a pretty high range. Below are query plan result values I have observed:

StartDate > '2019-12-01' --cost = 699168
StartDate = '2019-12-21' --cost 70666
StartDate between '2019-12-21' and '2019-21-28' --cost = 492058

The query plans above were for type %TimeStamp.

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Hello everyone!

Some time ago, I changed the configuration in SQL Runtime Statistic to "Turn on Stats code generation to gather stats at the Open and Close of a query". With this change, the CACHE base (cache/mgr/cache/) has grown a lot to reach 198GB.

Yesterday, I returned the configuration of SQL Runtime Statistic to the default which is "Turn off Stats code generation" and the cache base is no longer growing.

My question is?

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Hello,

I am trying to work out if there are any methods available to be able import a result set returned by SQL query into a persistent class.

I have to connect to some legacy SQL databases through SQL Gateway and run some queries. I need to inster the rows returned into a class to then be able to do a %JSONExport to produce a JSON object. I know I can iterate through the resultset and insert one row at a time into the class but was wondering if there is any other/direct way of importing the resultset rows into a class.

Regards,

Utsavi

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Hello everyone

I am new to cache. In an interview i was asked how to optimize a sql query.

I just said I will create index on conditions which are present in where clause. But as per interviewer I should check How query plan is getting executed. This will help in optimizing Sql queries.

I want to know what will be the answer for how to optimize SQL query in cache.

Thanks in advance!!

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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

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I'm new to cache, come from an oracle and sql server background. In oracle and sql server I could write basically a stored procedure like script and pass it in as text to the command to execute.

Example:

Below would be the _sqltext

DECLARE @Id INT;

select id into @Id from something;

if @Id = 9

BEGIN

do something

END

The _sqltext would work in sql server, what would be the equivalent for cache for it work?

I get a generic error when I try it with cache

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Hi Developers,

Enjoy watching the new video on InterSystems Developers YouTube:

⏯ InterSystems IRIS Cloud SQL @ Global Summit 2022

https://www.youtube.com/embed/QLaAH5o60y0
[This is an embedded link, but you cannot view embedded content directly on the site because you have declined the cookies necessary to access it. To view embedded content, you would need to accept all cookies in your Cookies Settings]

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I need a stored procedure where I can execute multiple delete from statements.

This will work to create a stored procedure, but when I add in other delete from, get error invalid sql statements when try to create

CREATE PROCEDURE DeleteSpecimenTwo
(IN Specno VARCHAR(50))
BEGIN
DELETE FROM PCONT WHERE PSPECNO = :Specno;
END;

This doesn't work

CREATE PROCEDURE DeleteSpecimenTwo
(IN Specno VARCHAR(50))
BEGIN
DELETE FROM PCONT WHERE PSPECNO = :Specno;

DELETE FROM PSPEC WHERE PSPECNO = :Specno;
END;

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Question
· Aug 31, 2023
SELECT command within CSP

The program below works perfectly when I call it directly from the Terminal, however when I call it from within a CSP it does not work (It does not do the SELECT).

In the USER namespace, the program works both in the Terminal and on the CSP , but in another namespace it only works when called directly in the Terminal.

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Hi Community,

I am attempting to create a new table by executing a SELECT statement that involves joining multiple tables. However, I encountered an error during execution: '( expected, AS found^Combined AS.' I would also like to create a cube based on this SQL table. However, during the cube creation process, I am prompted to specify a source class, and I'm unsure which class to use as it requires an existing class. Could you please help me identify the issue with the table creation, and provide guidance on selecting the appropriate source class for the cube creation?"

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Hi All,

On February 8, 2024, we asked for input from the IRIS community regarding exam topics for our InterSystems IRIS Developer Specialist exam. We will close the window for providing feedback on the exam topics on Friday, March 8, 2024. If you would like to have your say in what topics are covered on the exam, this is your last chance!

How can I access the survey? You can access it here

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Given a complex method flagged with [ SqlProc ] so it is available as an SQL stored procedure, what's the best way to report a non-system error detected in that method - say, for example, an error %Status - so that the SQL query calling it fails descriptively? Is it best to create and throw an exception, or are there special % variables involved (like in a trigger)? I haven't been able to find an answer in the documentation.

Thanks in advance!

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When working with a large query executed though an ODBC connection what is the best way to allow the paging of the results at the client side. I have tried some methods using %VID and similar methods, but these really don't seem to work as the value returned is related to the ID of the data and not the position in the results set. What would be ideal is if the value seen in the management portal when you check of "Row Number" was available to external queries through ODBC. I have not seen a way to return this however.

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Hi All,

I use SQL function JSON_OBJECT to get data as a JSON object.

However, sometimes I get error with function JSON_OBJECT when values contain [, ], { or }.

Error:

[SQLCODE: <-400>:<Fatal error occurred>]

Unexpected error occurred in JSON_OBJECT() function execution of <JSON_OBJECT>.%FromJSON().Parsing error

For example,

Query: SELECT JSON_OBJECT('idSQL':id, 'content':content) FROM DocBook.block

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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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