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#SQL

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

All time

Date range queries going too slow for you? SQL Performance got you down? I have one weird trick that might just help you out! (SQL Developers hate this!)*

If you have a class that records timestamps when the data is added, then that data will be in sequence with your IDKEY values - that is, TimeStamp1 < TimeStamp2 if and only if ID1 < ID2 for all IDs and TimeStamp values in table - then you can use this knowledge to increase performance for queries against TimeStamp ranges. Consider the following table:

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I have a query string that I am creating programmatically, based on some user inputs. The user might search on 5 fields, or 8 fields, or no fields.

In my sql statment, some of these fields require parameters in the %Execute statement.

For example:

if user picks lastname, sql = "select * from person where lastname = ?"

if user also picks age, sql = "select * from person where lastname=? and age > ?"

I then have these lines of code to create my result set:

set statement = %SQL.Statement

statement.%Prepare

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The Caché System Management Portal includes a robust web-based SQL query tool, but for some applications it’s more convenient to use a dedicated SQL client installed on a user’s PC.

SQuirreL SQL is a well known open source SQL client built in Java, which uses JDBC to connect to a DBMS. As such, we can configure SQuirreL to connect to Caché using the Caché JDBC driver.

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We use ExecureProcedure() to execute a stored procedure which returns a result set. But we see lot of "Invalid cursor state" errors when the result set is empty. The connection to SQL server database is made through ODBC.

ERROR #6022: Gateway failed: Fetch. + ERROR <Ens>ErrGeneral: SQLState: (24000) NativeError: [0] Message: [Microsoft][ODBC Driver 11 for SQL Server]Invalid cursor state

Here is the code snippet from the business operation class which uses EnsLib.SQL.OutboundAdapter

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Article
· Feb 5, 2016 11m read
Class Queries in InterSystems IRIS

Class Queries in InterSystems IRIS (and Cache, Ensemble, HealthShare) is a useful tool that separates SQL queries from Object Script code. Basically, it works like this: suppose that you want to use the same SQL query with different arguments in several different places.In this case you can avoid code duplication by declaring the query body as a class query and then calling this query by name. This approach is also convenient for custom queries, in which the task of obtaining the next row is defined by a developer. Sounds interesting? Then read on!

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Question
· Feb 12, 2016
Help with SQL error

Error:

[SQLCODE: <-400>:<Fatal error occurred>]
[Cache Error: <<SUBSCRIPT>%0AmEdun+4^%sqlcq.HSREGISTRY.cls966.1 ^||%sql.temp(1,"")>]
[Location: <ServerLoop - Query Fetch>]
[%msg: <Unexpected error occurred: <SUBSCRIPT>%0AmEdun+4^%sqlcq.HSREGISTRY.cls966.1 ^||%sql.temp(1,"")>]

Here is an example of a query that gives the error:

SELECT COUNT(DISTINCT Criteria) as Relevance FROM HS_IHE_ATNA_Repository.Aggregation
WHERE EventType = 'CROSS GATEWAY QUERY'

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Article
· Nov 14, 2016 14m read
Mastering the JDBC SQL Gateway

As we all know, Caché is a great database that accomplishes lots of tasks within itself. However, what do you do when you need to access an external database? One way is to use the Caché SQL Gateway via JDBC. In this article, my goal is to answer the following questions to help you familiarize yourself with the technology and debug some common problems.

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I have been using the query below and it was working fine but now it's giving a SQL error. There were no changes made that could cause this to stop working. There is no Field 'APPLICATIONID' in the table.

QueueSQL=select distinct (convert(char(5),SkillsetID)+'='+Skillset) from iagentbySkillsetStat where ApplicationID > 10000
QueueMappingSQL=SELECT DISTINCT (convert(char(5),SkillsetID)+'='+Skillset), SkillsetID FROM iagentbySkillsetStat iagentbySkillsetStat WHERE (iagentbySkillsetStat.ApplicationID>10000)

DB- Intersystems Cache

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Announcement
· Aug 25, 2016
JSON changes in Caché 2016.2

As Bill has mentioned earlier in his post, we have carefully reviewed the JSON capabilities and made some adjustments to ensure they deliver the best benefit to you. In this post, I am going to describe the modifications in more detail and provide guidance for you to understand the implication for your code base.

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We have a new requirement being push down by our Data Security to no longer use Local SQL Accounts to access our Databases. So they asked me to create a Service Account that is on the Domain for our connections to each database.

I tried just changing my JDBC connection to using this Service Account and Password but I am not having any luck trying to connect to the database.

" Connection failed.
Login failed for user 'osumc\CPD.Intr.Service'. ClientConnectionId:ade97239-c1c8-4ed1-8230-d274edb2e731 "

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Introduction

In the first article in this series, we’ll take a look at the entity–attribute–value (EAV) model in relational databases to see how it’s used and what it’s good for. Then we'll compare the EAV model concepts to globals.

Open Exchange app
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Article
· Jun 12, 2023 3m read
LangChain fixed the SQL for me

This article is a simple quick starter (what I did was) with SqlDatabaseChain.

Hope this ignites some interest.

Many thanks to:

sqlalchemy-iris author @Dmitry Maslennikov

Your project made this possible today.

The article script uses openai API so caution not to share table information and records externally, that you didn't intend to.

A local model could be plugged in , instead if needed.

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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?

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Question
· Jul 17, 2018
Cache Dynamic SQL Pagination

Would like to know if there is an alternative or better way to paginate through a dataset using dynamic SQL than what I am using below. The problem is that as the potential pool of data gets larger, this code slows down to the point of not being useable. In analyzing each line of code below, it appears the slow down is related to the initial rset.%Next() iteration. Is there anything available which does not require a subquery/%VID such as a simple LIMIT/OFFSET?

My code is similar to :

s sql=##class(%SQL.Statement).%New()

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Hi,

I'm doing a query in SQL and I need to sort my data by some non-repeated field.

Unfortunately, my data is grouped in a way that I cannot guarantee that any column will not have repeated data, so one solution would be to take the row number.

Also, the Cache is not accepting Row_Number () in my querry and I would like to know if there is another solution to return line numbers or some way to add this function to the Cache.

Best regards.

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I am trying to make architecture for my project. And for it, it needs to make list property in which there is list of objects of another table, the data must be unique, therefore I make sql-query to check objects of another table if it is used or not, but I can't make sql-query to check elements in list in property with elements of another table. Can you help me? In property ID of object is used.

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Question
· Mar 12, 2019
String to date

I am trying to convert a string to date but can not get it to work I have function that I would like to take in a date string and covert it to date object

here is the ezample so far can not get it to work any help appreciated 

set p="12/03/2019"
 
w $System.SQL.TODATE(p,"YYYY-MM-DD")
 
<ILLEGAL VALUE>todate+32^%qarfunc

if I try this still get the wrong value returned

set p="12/03/2019" 
w $ZDATE(p,3)
1841-01-12
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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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Article
· May 20, 2016 12m read
Collations in Caché

Order is a necessity for everyone, but not everyone understands it in the same way
(Fausto Cercignani)

Disclaimer: This article uses Russian language and Cyrillic alphabet as examples, but is relevant for anyone who uses Caché in a non-English locale.
Please note that this article refers mostly to NLS collations, which are different than SQL collations. SQL collations (such as SQLUPPER, SQLSTRING, EXACT which means no collation, TRUNCATE, etc.) are actual functions that are explicitly applied to some values, and whose results are sometimes explicitly stored in the global subscripts. When stored in subscripts, these values would naturally follow the NLS collation in effect (“SQL and NLS Collations”).

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Introduction

The field test of Caché 2016.2 has been available for quite some time and I would like to focus on one of the substantial features that is new in this version: the document data model. This model is a natural addition to the multiple ways we support for handling data including Objects, Tables and Multidimensional arrays. It makes the platform more flexible and suitable for even more use cases.

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