With the following results :

write ##class(MyApp.Account).TestAccount()
Deposit succeeded: Balance after deposit: 100
Deposit of negative amount failed as expected: ERROR #5001: Deposit amount must be non-negative
Withdrawal succeeded: Balance after withdrawal: 50
Withdrawal of more than available balance failed as expected: ERROR #5001: Insufficient funds
Balance invariant holds true
Balance invariant violated as expected: ERROR #5001: Balance invariant violated: Balance is negative
Account operations completed successfully
1

Very good point @Herman Slagman 
To illustrate your point, in ObjectScript :

Include %occErrors

Class MyApp.Account Extends %Persistent
{

Property Balance As %Numeric;

/// Deposit money into the account
Method Deposit(amount As %Numeric) As %Status
{
    // Preconditions
    If amount < 0 {
        Return $$$ERROR($$$GeneralError, "Deposit amount must be non-negative")
    }

    // Store the old balance
    Set oldBalance = ..Balance

    // Update balance
    Set ..Balance = oldBalance + amount

    // Postconditions
    If (..Balance '= $$$NULLOREF) && (..Balance '= (oldBalance + amount)) {
        Return $$$ERROR($$$GeneralError, "Postcondition failed: Balance calculation error")
    }

    Quit $$$OK
}

/// Withdraw money from the account
Method Withdraw(amount As %Numeric) As %Status
{
    // Preconditions
    If amount < 0 {
        Return $$$ERROR($$$GeneralError, "Withdrawal amount must be non-negative")
    }
    If (..Balance = $$$NULLOREF) || (..Balance < amount) {
        Return $$$ERROR($$$GeneralError, "Insufficient funds")
    }

    // Store the old balance
    Set oldBalance = ..Balance

    // Update balance
    Set ..Balance = oldBalance - amount

    // Postconditions
    If (..Balance '= $$$NULLOREF) && (..Balance '= (oldBalance - amount)) {
        Return $$$ERROR($$$GeneralError, "Postcondition failed: Balance calculation error")
    }

    Quit $$$OK
}

/// Invariant: Balance should always be non-negative
Method CheckBalanceInvariant() As %Status
{
        Set tSC = $$$OK
        If ..Balance < 0 {
            Set tSC = $$$ERROR($$$GeneralError, "Balance invariant violated: Balance is negative")
        }
        Quit tSC
}

/// Class method to test the Account class
ClassMethod TestAccount() As %Status
{
    // Create a new instance of Account
    Set account = ##class(MyApp.Account).%New()
    
    // Initialize the balance
    Set account.Balance = 0
    
    // Test depositing a positive amount
    Set tSC = account.Deposit(100)
    If $$$ISERR(tSC) {
        Write "Deposit failed: ", $system.Status.GetErrorText(tSC), !
        Quit tSC
    }
    Write "Deposit succeeded: Balance after deposit: ", account.Balance, !
    
    // Test depositing a negative amount (should fail)
    Set tSC = account.Deposit(-50)
    If $$$ISERR(tSC) {
        Write "Deposit of negative amount failed as expected: ", $system.Status.GetErrorText(tSC), !
    } Else {
        Write "Deposit of negative amount unexpectedly succeeded", !
        Quit $$$ERROR($$$GeneralError, "Deposit of negative amount unexpectedly succeeded")
    }
    
    // Test withdrawing a valid amount
    Set tSC = account.Withdraw(50)
    If $$$ISERR(tSC) {
        Write "Withdrawal failed: ", $system.Status.GetErrorText(tSC), !
        Quit tSC
    }
    Write "Withdrawal succeeded: Balance after withdrawal: ", account.Balance, !
    
    // Test withdrawing more than the available balance (should fail)
    Set tSC = account.Withdraw(200)
    If $$$ISERR(tSC) {
        Write "Withdrawal of more than available balance failed as expected: ", $system.Status.GetErrorText(tSC), !
    } Else {
        Write "Withdrawal of more than available balance unexpectedly succeeded", !
        Quit $$$ERROR($$$GeneralError, "Withdrawal of more than available balance unexpectedly succeeded")
    }
    
    // Check balance invariant (should succeed)
    Set tSC = account.CheckBalanceInvariant()
    If $$$ISERR(tSC) {
        Write "Balance invariant violated: ", $system.Status.GetErrorText(tSC), !
        Quit tSC
    }
    Write "Balance invariant holds true", !
    
    // Intentionally set balance to negative value to trigger balance invariant failure
    Set account.Balance = -10
    
    // Check balance invariant (should fail)
    Set tSC = account.CheckBalanceInvariant()
    If $$$ISERR(tSC) {
        Write "Balance invariant violated as expected: ", $system.Status.GetErrorText(tSC), !
    } Else {
        Write "Balance invariant unexpectedly held true", !
        Quit $$$ERROR($$$GeneralError, "Balance invariant unexpectedly held true")
    }
    
    Write "Account operations completed successfully", !
    Quit $$$OK
}

Storage Default
{
<Data name="AccountDefaultData">
<Value name="1">
<Value>%%CLASSNAME</Value>
</Value>
<Value name="2">
<Value>Balance</Value>
</Value>
</Data>
<DataLocation>^MyApp.AccountD</DataLocation>
<DefaultData>AccountDefaultData</DefaultData>
<IdLocation>^MyApp.AccountD</IdLocation>
<IndexLocation>^MyApp.AccountI</IndexLocation>
<StreamLocation>^MyApp.AccountS</StreamLocation>
<Type>%Storage.Persistent</Type>
}

}

Many thanks @Alex Woodhead for your article.

For those who want to start with Alex's example, you can use the code below or online (process + production)

/// 
Class python.process.demo Extends Ens.BusinessProcessBPL
{

/// BPL Definition
XData BPL [ XMLNamespace = "http://www.intersystems.com/bpl" ]
{
<process language='python' request='Ens.StringRequest' response='Ens.StringResponse' height='2000' width='2000' >
<pyFromImport>
import requests
</pyFromImport>
<sequence xend='200' yend='1050' >
<switch name='What Drink' xpos='200' ypos='250' xend='200' yend='500' >
<annotation><![CDATA[looking for Drink keyword in request]]></annotation>
<case condition='request.StringValue.lower().find("coffee")&gt;0' name='is coffee' languageOverride='python' >
<assign name="Coffe" property="response.StringValue" value="&quot;Coffee&quot;" action="set" languageOverride="objectscript" xpos='200' ypos='400' />
</case>
<case condition='request.StringValue.lower().find("tea")&gt;0' name='is tea' languageOverride='python' >
<assign name="Tea" property="response.StringValue" value="&quot;Tea&quot;" action="set" languageOverride="objectscript" xpos='470' ypos='400' />
</case>
<default>
<assign name="Chocolate" property="response.StringValue" value="&quot;Chocolate&quot;" action="set" languageOverride="objectscript" xpos='740' ypos='400' />
</default>
</switch>
<if name='Is White' condition='request.StringValue.lower().find("black")==-1' languageOverride="python" xpos='200' ypos='600' xend='200' yend='850' >
<annotation><![CDATA[looking for absence of keyword "black" in request]]></annotation>
<true>
<assign name="Add Milk" property="response.StringValue" value="response.StringValue + &quot; MILK&quot;" action="set" languageOverride="python" xpos='335' ypos='750' />
</true>
</if>
<assign name="Add Hot Water" property="response.StringValue" value="response.StringValue + &quot; HOT WATER&quot;" action="set" languageOverride="python" xpos='200' ypos='950' />
</sequence>
</process>
}

Storage Default
{
<Type>%Storage.Persistent</Type>
}

}

Hi Zhang,

you'll find a JDBC example below : 

import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class RetrieveBlob {

  public static void main(String[] args) throws Exception {
    // Replace with your connection details
    String url = "jdbc:mysql://localhost:3306/your_database";
    String username = "your_username";
    String password = "your_password";

    Connection conn = DriverManager.getConnection(url, username, password);

    String sql = "SELECT image FROM your_table WHERE id = ?";
    PreparedStatement stmt = conn.prepareStatement(sql);
    stmt.setInt(1, 1); // Replace with the ID you want to query

    ResultSet rs = stmt.executeQuery();

    if (rs.next()) {
      Blob blob = rs.getBlob("image"); // Replace "image" with your column name

      // Option 1: Get Bytes
      byte[] imageBytes = blob.getBytes(1, (int) blob.length()); // Get all bytes
      // Process the imageBytes byte array

      // Option 2: Stream Processing
      // InputStream in = blob.getBinaryStream();
      // ... process the stream
    }

    rs.close();
    stmt.close();
    conn.close();
  }
}

Congrats @Robert Cemper 👏
Your tireless contribution to the community is a model that no one will be able to match.

Thanks @Alberto Fuentes 
I suggest to keep information regarding the classname of the message and its ID :

Method %ShowContents(pZenOutput As %Boolean = 0)
{
   do ..%JSONExportToString(.jsonExport)
    set formatter = ##class(%JSON.Formatter).%New()
    do formatter.FormatToString(jsonExport, .json)
    &html<
        <i style="color:green;">type: #($classname())#  id: #(..%Id())# </i>
        <pre>#(json)#</pre>
    >
}

 in order to get :

Many thanks @Vitaliy Serdtsev ; this is exactly what I needed.

Congrats @José Roberto Pereira, @Henry Pereira, @Henrique Dias , @Muhammad Waseem, @Flavio Naves, Denis Kiselev, Maria Ogienko, Anastasia Samoilova, Kseniya Hoar  and all the participants to this FHIR contest !!

Hello @Ashok Kumar T 
this SQL query is very powerful, but I'm not able to make it work neither with simple TOP, nor with %VID in order to get a pagination.

SELECT top 5
         JSON_ARRAYAGG(
          JSON_OBJECT(
             'Name':name
             ,'Age':age
             ,'DOB':to_char(dob,'Day DD Month YYYY')
            )
         ) 
         FROM sample.person

SELECT *
   FROM (SELECT
         JSON_ARRAYAGG(
          JSON_OBJECT(
            'Name':name
            ,'Age':age
            ,'DOB':to_char(dob,'Day DD Month YYYY')
          )
        ) 
         FROM sample.person)
WHERE %VID BETWEEN 1 AND 5

in both cases, I get the full table with all its records.

Hello, 

with IRIS you can avoid the now deprecated %ZEN.Auxiliary and rather use %DynamicObject / %DynamicArray : 

ObjectScript : 

ClassMethod getJSON() As %String
{
    set query = "SELECT top 3 name,age,to_char(dob,'Day DD Month YYYY') as dob FROM sample.person"
    set rs=##class(%SQL.Statement).%ExecDirect(,query)

    set list = []
    while rs.%Next() {
        set row = {"name":(rs.%Get("name")),"age":(rs.%Get("age")),"dob":(rs.%Get("dob"))}
        do list.%Push(row)
    }
    set result = {"results":(list.%Size()),"items":(list)}
    return result.%ToJSON()
}

Result : 

write ##class(resultset).getJSON()
{"results":3,"items":[{"name":"Pantaleo,Mary Q.","age":36,"dob":"Monday 07 December 1987"},{"name":"Underman,Laura I.","age":71,"dob":"Friday 16 May 1952"},{"name":"Huff,Lydia J.","age":26,"dob":"Sunday 09 November 1997"}]}

Embedded Python :  

ClassMethod get() As %String [ Language = python ]
{
import iris
import json
query = "SELECT top 3 name,age,to_char(dob,'Day DD Month YYYY') FROM sample.person"
rs=iris.sql.exec(query)

list = []
for idx, x in enumerate(rs):
    row = {"name":x[0],"age":x[1],"dob":x[2]}
    list.append(row)
result = {"results":len(list),"items":list}
return json.dumps(result)
}

Result : 

write ##class(resultset).get()
{"results": 3, "items": [{"name": "Pantaleo,Mary Q.", "age": 36, "dob": "Monday 07 December 1987"}, {"name": "Underman,Laura I.", "age": 71, "dob": "Friday 16 May 1952"}, {"name": "Huff,Lydia J.", "age": 26, "dob": "Sunday 09 November 1997"}]}

With embedded python you can get your JSON with few lines of code.

resultsetJSONembedded.py :

import os
import getpass
if not 'IRISUSERNAME' in os.environ:
    os.environ['IRISUSERNAME'] = input('set IRISUSERNAME [_SYSTEM] :') or "_SYSTEM"
if not 'IRISPASSWORD' in os.environ:
    os.environ['IRISPASSWORD'] = getpass.getpass('set IRISPASSWORD [SYS]:') or 'SYS'
if not 'IRISNAMESPACE' in os.environ:
    os.environ['IRISNAMESPACE'] = input('set IRISNAMESPACE [IRISAPP] :') or "IRISAPP"
import iris
import json
query = "SELECT top 5 name,age,to_char(dob,'Day DD Month YYYY') FROM sample.person"
rs=iris.sql.exec(query)

list = []
for idx, x in enumerate(rs):
    row = {"name":x[0],"age":x[1],"dob":x[2]}
    list.append(row)
result = {"results":len(list),"items":list}
print(json.dumps(result))

Result :

irispython resultsetJSONembedded.py 
set IRISUSERNAME [_SYSTEM] :
set IRISPASSWORD [SYS]:
set IRISNAMESPACE [IRISAPP] :
{"results": 3, "items": [{"name": "Xander,Dan T.", "age": 35, "dob": "Tuesday 10 January 1989"}, {"name": "Kratzmann,Jane O.", "age": 34, "dob": "Thursday 14 September 1989"}, {"name": "Ingrahm,Bill S.", "age": 82, "dob": "Saturday 01 November 1941"}]}

or if you prefer export environment variables (without exposing the IRISPASSWORD) :

export IRISUSERNAME=_SYSTEM
export IRISNAMESPACE=IRISAPP
irispython resultsetJSONembedded.py 
set IRISPASSWORD [SYS]:
{"results": 3, "items": [{"name": "Xander,Dan T.", "age": 35, "dob": "Tuesday 10 January 1989"}, {"name": "Kratzmann,Jane O.", "age": 34, "dob": "Thursday 14 September 1989"}, {"name": "Ingrahm,Bill S.", "age": 82, "dob": "Saturday 01 November 1941"}]}

{"results": 3, "items": [{"name": "Xander,Dan T.", "age": 35, "dob": "Tuesday 10 January 1989"}, {"name": "Kratzmann,Jane O.", "age": 34, "dob": "Thursday 14 September 1989"}, {"name": "Ingrahm,Bill S.", "age": 82, "dob": "Saturday 01 November 1941"}]}

Hi,

I know your question was about ObjectScript, but if Python is allowed in your environment, I suggest to use it to get JSON : 

resultsetJSON.py :

import iris
import json
import getpass
import os
if 'IRISHOSTNAME' in os.environ:
    hostname = os.environ['IRISHOSTNAME']
else:
    hostname = input('hostname [localhost] :') or "localhost"
if 'IRISPORT' in os.environ:
    port = os.environ['IRISPORT']
else:
    port = input('port [1972] :') or "1972"
if 'IRISUSERNAME' in os.environ:
    username = os.environ['IRISUSERNAME']
else:
    username = input('login [_SYSTEM] :') or "_SYSTEM"
if 'IRISPASSWORD' in os.environ:
    password = os.environ['IRISPASSWORD']
else:
    password = getpass.getpass('password [SYS]:') or 'SYS'
if 'IRISNAMESPACE' in os.environ:
    namespace = os.environ['IRISNAMESPACE']
else:
    namespace = input('namespace [IRISAPP] :') or "IRISAPP"
connection_string = hostname + ":" + port + "/" + namespace
connectionIRIS = iris.connect(connection_string, username, password)
cursorIRIS = connectionIRIS.cursor()
print("Connected to",connection_string)

query = "SELECT top 3 name,age,to_char(dob,'Day DD Month YYYY') FROM sample.person"
cursorIRIS.execute(query)
 
resultSet = cursorIRIS.fetchall()

list = []
result = {"results":len(resultSet),"items":list}
for x in resultSet:
    row = {"name":x[0],"age":x[1],"dob":x[2]}
    list.append(row)
print(json.dumps(result))
 
connectionIRIS.close()

Result :

python resultsetJSON.py
hostname [localhost] :
port [1972] :51779
login [_SYSTEM] :
password [SYS]:
namespace [IRISAPP] :
Connected to localhost:51779/IRISAPP
{"results": 3, "items": [{"name": "Pantaleo,Mary Q.", "age": 36, "dob": "Monday 07 December 1987"}, {"name": "Underman,Laura I.", "age": 71, "dob": "Friday 16 May 1952"}, {"name": "Huff,Lydia J.", "age": 26, "dob": "Sunday 09 November 1997"}]}

{
"results":3,
"items":[
{
"name":"Pantaleo,Mary Q.",
"age":36,
"dob":"Monday 07 December 1987"
},
{
"name":"Underman,Laura I.",
"age":71,
"dob":"Friday 16 May 1952"
},
{
"name":"Huff,Lydia J.",
"age":26,
"dob":"Sunday 09 November 1997"
}
]
}

Very good article ; thank you @Luis Angel Pérez Ramos 
For those who want to extend the discovery of FHIR, you can access the online documentation on the official web site.

Thanks @Alberto Fuentes for this very good example of LLM + Embedded Python.

Welcome to Developer Community moderators @Enrico Parisi 
'Hoping you're doing well.

Hi @Theo Stolker 

the log is managed by the ^FSLogChannel global.

 set ^FSLogChannel(channelType) = 1

For example, to enable logging for all types of information, enter:

 set ^FSLogChannel("all") = 1

ChannelType is one of the following:

• Msg — Logs status messages.
• SQL — Logs SQL-related information.
• _include — Logs information related to searches that use the _include and _revinclude parameters.
• all — Logs all three types of information.

That's very handy ; thank you @Evgeny Shvarov