Bold for Delphi - Quick Start Guide 🚀

February 21, 2026 · View on GitHub

Get your first Bold application running in 15 minutes! ⏱️

What is Bold? 💡

Bold for Delphi is a Model-Driven Architecture (MDA) framework that:

  • Lets you define your domain model in UML
  • Auto-generates strongly-typed Delphi classes from your model
  • Handles object-relational mapping (ORM) to any database
  • Provides OCL (Object Constraint Language) for queries
  • Includes data-aware VCL components with automatic UI updates

The core idea: You work with objects, Bold handles the database.

UML Model → Code Generator → Business Classes → Bold Runtime → Database

Prerequisites ✅

  • Delphi 11.3, 12.1 CE, 12.3, or 13
  • Database: The following FireDAC-supported databases should work. SQLite, SQL Server, PostgreSQL, Firebird, MariaDB/MySQL and Oracle. SQLite requires no installation.
  • Bold packages installed (see Installation below)

Installation 📦

Step 1: Get the Source

git clone https://github.com/bero/BoldForDelphi.git

Or download and extract to a folder like C:\BoldForDelphi.

Step 2: Get the Packages

Option A: Download Pre-built Binaries (Recommended)

Download the binary package for your Delphi version from: https://github.com/bero/BoldForDelphi/releases/

Extract to packages\Bin\. Add the new package from menu Component/Install packages...

Then press Add and select your bpl-file

Option B: Build from Source 🔧

Compiling from source gives you the latest version, or lets you use Bold with unsupported Delphi versions.

Open the package project for your Delphi version in the IDE:

Delphi VersionOpen this file
Delphi 11.3 Alexandriapackages\Delphi11.3\dclBold.dproj
Delphi 12.1 CE Athenspackages\Delphi12.1_CE\dclBold.dproj
Delphi 12.3 Athenspackages\Delphi12.3\dclBold.dproj
Delphi 13 Athenspackages\Delphi13\dclBold.dproj

Then:

  1. File → Open Project and select the .dproj from the table above
  2. Project → Build (or Shift+F9) to compile the package
  3. In the Project Manager panel, right-click the .bpl and choose Install
  4. Verify via menu Component → Install Packages... — you should see "Bold for Delphi" in the list

The compiled BPL is output to packages\Bin\.

You should now see Bold components in the Tool Palette. 🎉

Using an unsupported Delphi version:

If your Delphi version is not listed above:

  1. Copy the folder of the closest supported version (e.g., copy Delphi13 for Delphi 14)
  2. Rename the folder to match your Delphi version (e.g., Delphi14)
  3. Open dclBold.dproj in the IDE
  4. Go to Project → Options → Description and update the Lib Suffix to match your compiler version
  5. Build and install as described above
  6. If it works, consider submitting a pull request to include the new package folder

Your First Bold Application 🏗️

First option is to look at a ready-made small app: examples\Simple\ObjectSpace\MasterDetail\MasterDetail.dproj

Important: This example uses design-time Bold components, so you must install the Bold package first (Step 2 above). Then open and compile MasterDetail. It defaults to SQLite — no database server needed, just press F9.

Second option is to build app from scratch. More fun and more learning 😊 We'll build a simple app with Person and Building objects, where persons can own buildings.

Step 1: Create a New VCL Application

  1. File → New → VCL Forms Application
  2. Save the project (e.g. Building.dproj)

Step 2: Add a Data Module

  1. File → New → Other → Delphi Files → Data Module
  2. Save as DataModule1.pas

Step 3: Add Core Bold Components

Drop these components on your DataModule from the Bold palette:

ComponentPurpose
TBoldModelHolds your UML model
TBoldSystemHandleMain runtime system
TBoldSystemTypeInfoHandleType information for design-time
TBoldPersistenceHandleDBDatabase persistence

Connect them:

  • BoldSystemHandle1.BoldModel → BoldModel1
  • BoldSystemHandle1.PersistenceHandle → BoldPersistenceHandleDB1
  • BoldSystemTypeInfoHandle1.BoldModel → BoldModel1

Step 4: Add Database Connection

  1. Drop a TFDConnection (FireDAC) on the DataModule

  2. Configure it for your database. SQLite is the easiest to start with — no server needed:

    [Database]
Persistence=FireDAC
Type=SQLite

[SQLite]
Database=BoldDemo.db

    The database file is created automatically on first run.

    Other database configurations (SQL Server, PostgreSQL, Firebird, MariaDB, Oracle)

    For SQL Server:

    [Database]
Persistence=FireDAC
Type=MSSQL

[MSSQL]
Server=localhost
Database=BoldDemo
OSAuthent=True
User=sa
Password=

    For PostgreSQL:

    [Database]
Persistence=FireDAC
Type=PostgreSQL

[PostgreSQL]
Server=localhost
Database=bolddemo
VendorLib=C:\Program Files\PostgreSQL\18\bin\libpq.dll
User=postgres
Password=<your_password>

    For Firebird:

    [Database]
Persistence=FireDAC
Type=Firebird

[Firebird]
Server=localhost
Database=C:\Data\BoldDemo.fdb
VendorLib=C:\Program Files\Firebird\Firebird_5_0\fbclient.dll
User=SYSDBA
Password=<your_password>

    For MariaDB (or MySQL):

    [Database]
Persistence=FireDAC
Type=MariaDB

[MariaDB]
Server=localhost
Port=3306
Database=bolddemo
User=root
Password=<your_password>
VendorLib=C:\Program Files\MariaDB\MariaDB Connector C 64-bit\lib\libmariadb.dll

    Note: MariaDB requires the MariaDB Connector/C client library. Download from https://mariadb.com/downloads/connectors/ (Connector/C, Windows 64-bit). For MySQL, point VendorLib to libmysql.dll instead.

    For Oracle:

    [Database]
Persistence=FireDAC
Type=Oracle

[Oracle]
Database=//localhost:1521/XEPDB1
User=bolduser
Password=<your_password>
VendorLib=C:\oracle\instantclient_23_7\oci.dll

    Note: Oracle requires the Oracle Instant Client. The Database parameter uses Easy Connect format: //host:port/service_name.

  3. Drop a TBoldDatabaseAdapterFireDAC component

  4. Set BoldDatabaseAdapterFireDAC1.Connection → FDConnection1

  5. Set BoldPersistenceHandleDB1.DatabaseAdapter → BoldDatabaseAdapterFireDAC1

Step 5: Create Your Model

  1. Double-click BoldModel1 to open the Model Editor
  2. Create your classes:

Person class:

  • Right-click → Add Class → Name: Person
  • Add attributes:
    • FirstName: String
    • LastName: String
    • Assets: Currency

Building class:

  • Add Class → Name: Building
  • Add attributes:
    • Address: String
    • ZipCode: Integer

Create an association (Ownership):

  • Select both classes
  • Right-click → Add Association
  • Name: Ownership
  • Person side: OwnedBuildings (0..*)
  • Building side: Owners (0..*)
  1. File → Save & Generate all files

This creates BusinessClasses.pas with strongly-typed classes.

Step 6: Add Business Classes to Project

  1. Add the generated BusinessClasses.pas to your project
  2. Add to DataModule uses clause: 
    uses
  BusinessClasses;

Step 7: Design the Main Form

On your main form, add:

List Handles (from Bold Handles palette):

  • TBoldListHandle named blhAllPersons

    • RootHandle → DataModule1.BoldSystemHandle1
    • Expression → Person.allInstances

  • TBoldListHandle named blhAllBuildings

    • RootHandle → DataModule1.BoldSystemHandle1
    • Expression → Building.allInstances

GUI Components (from Bold Controls palette):

  • TBoldGrid for persons → BoldHandle = blhAllPersons
  • TBoldGrid for buildings → BoldHandle = blhAllBuildings
  • TBoldNavigator → BoldHandle = blhAllPersons

Actions (from Bold Actions palette):

  • TBoldActivateSystemAction → Opens the database
  • TBoldUpdateDBAction → Saves changes to database
  • Add buttons linked to these actions

Step 8: Initialize the System

In your main form's OnCreate:

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Activate opens/creates the database and loads the model
  BoldActivateSystemAction1.Execute;
end;

Step 9: Run It! ▶️

  1. Press F9 to run
  2. Click "Open System" to activate
  3. Use the navigator to add Person records
  4. The grid automatically displays them
  5. Click "Update DB" to save

That's it! You have a working Bold application. ✅

Working with Objects in Code 💻

Bold generates clean, strongly-typed classes. Here's how to use them:

Creating Objects

var
  Person: TPerson;
  Building: TBuilding;
begin
  // Create objects - Bold tracks them automatically
  Person := TPerson.Create(BoldSystemHandle1.System);
  Person.FirstName := 'John';
  Person.LastName := 'Doe';
  Person.Assets := 50000;

  Building := TBuilding.Create(BoldSystemHandle1.System);
  Building.Address := '123 Main Street';
  Building.ZipCode := 12345;

  // Create relationship
  Person.OwnedBuildings.Add(Building);
end;

Querying with OCL

var
  RichPeople: TBoldObjectList;
begin
  // Find all persons with assets > 100000
  RichPeople := BoldSystemHandle1.System.EvaluateExpressionAsNewElement(
    'Person.allInstances->select(assets > 100000)'
  ) as TBoldObjectList;

  // Use type-safe access
  for var i := 0 to RichPeople.Count - 1 do
    ShowMessage(TPerson(RichPeople[i]).FirstName);
end;

Saving to Database

// Save all changes
BoldSystemHandle1.UpdateDatabase;

// Or discard changes
BoldSystemHandle1.System.Discard;

Key Concepts 📚

ConceptDescription
BoldSystemThe runtime container for all your objects
HandlesConnect UI components to objects (TBoldListHandle, TBoldExpressionHandle)
OCL ExpressionsQuery language: Person.allInstances->select(age > 30)
SubscriptionUI auto-updates when objects change
M_ propertiesDirect access to Bold members: Person.M_FirstName.AsString

Common OCL Expressions 🔍

Person.allInstances                      -- All persons
Person.allInstances->size                -- Count of persons
Person.allInstances->select(assets > 0)  -- Filter
Person.allInstances->collect(lastName)   -- Extract attribute
Person.allInstances->sortedBy(lastName)  -- Sort
self.ownedBuildings->size                -- Count related objects
self.firstName + ' ' + self.lastName     -- Concatenation

Next Steps 🚶

  1. Explore the Examples: See examples/Compound/Building/ for a more complex sample (note: this is a legacy Delphi 7 project — use it as a code reference, not as a compilable project)
  2. Read the Tutorials: Check Doc/Starting Bfd - Part 1, 2, 3.pdf
  3. Learn OCL: See Doc/ad970808_UML11_OCL.pdf for the OCL specification
  4. Try Derived Attributes: Computed values that auto-update
  5. Add Constraints: Validate your model with OCL constraints

Troubleshooting 🔧

"Bold.inc not found"

  • Add Source\Common\Include to your project's search path

Components not showing in palette

  • Verify the BPL is installed (Component → Install Packages)
  • Check that all dependent packages are loaded in menu Component/Install packages...

Database errors on first run

  • Use TBoldCreateDatabaseAction to create the schema first
  • Or call BoldPersistenceHandleDB1.CreateDataBaseSchema

PostgreSQL: "libpq.dll not found" or connection fails

  • Copy libpq.dll and its dependencies to your executable folder (see Step 4)
  • The DLLs are in your PostgreSQL installation's bin folder

Firebird: "fbclient.dll not found" or connection fails

  • Copy fbclient.dll to your executable folder (see Step 4)
  • The DLL is in your Firebird installation folder

MariaDB/MySQL: "libmysql.dll not found" or connection fails

  • MariaDB Server does not include the client library - you need MariaDB Connector/C
  • Download from https://mariadb.com/downloads/connectors/ (Connector/C, Windows 64-bit)
  • Set VendorLib in your INI to point to libmariadb.dll
  • For MySQL, point VendorLib to libmysql.dll in your MySQL installation

Oracle: "oci.dll not found" or connection fails

Oracle: ORA-01400 "cannot insert NULL" errors

  • This can occur if your database schema was created with an older Bold version
  • Use the "Reset Oracle Schema" option in the demo app to recreate tables
  • Or manually drop all tables and let Bold recreate them

SQLite: Database file not created

  • SQLite creates the database file automatically on first connection
  • Check that the path in the INI file is writable
  • The file will be created in the same folder as the executable if no path is specified

Resources 🔗

Bold for Delphi - Model-Driven Development for Delphi since 2004