TinyORM/docs/building/hello-world.mdx

---
sidebar_position: 2
sidebar_label: Hello world
description: Hello world example created in the terminal and QtCreator IDE.
keywords: [c++ orm, building, hello world, tinyorm]
---

import CodeBlock from '@theme/CodeBlock'
import TabItem from '@theme/TabItem'
import Tabs from '@theme/Tabs'

import {
    shell,
    application, bash, pwsh,
    bash_label, pwsh_label
} from '@theme/constants'
import {
    applicationFolder,
    applicationFolderPath,
    convertToCmakeEnvVariable,
    rootFolderPath
} from '@theme/utils/rootFolderUtils'

# Building: Hello world

- [Introduction](#introduction)
- [Prepare SQLite 3 database](#prepare-sqlite-3-database)
- [Install dependencies](#install-dependencies)
    - [Using vcpkg.json](#using-vcpkg-json)
    - [Using vcpkg install](#using-vcpkg-install)
- [Source code](#source-code)
- [Hello world with CMake](#hello-world-with-cmake)
    - [CMake project](#cmake-project)
    - [Build Hello world](#build-hello-world-cmake)
    - [Execute Hello world](#execute-hello-world-cmake)
- [Hello world with qmake](#hello-world-with-qmake)
    - [qmake project](#qmake-project)
    - [Build Hello world](#build-hello-world-qmake)
    - [Execute Hello world](#execute-hello-world-qmake)

## Introduction

We will try to create the simplest working application in the terminal with the `CMake` and in the `QtCreator` IDE with the `qmake`.

The `HelloWorld` example also expects the following [folders structure](building/tinyorm.mdx#folders-structure), let's create them.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`cd ${applicationFolderPath(pwsh)}
mkdir HelloWorld/HelloWorld
cd HelloWorld`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`cd ${applicationFolderPath(bash)}
mkdir -p HelloWorld/HelloWorld
cd HelloWorld`}
</CodeBlock>
</TabItem>
</Tabs>

## Prepare SQLite 3 database

Simplest will be to demonstrate the `HelloWorld` example with the `SQLite 3` database.

To create and insert two rows into the `SQLite 3` database, execute the following command in the terminal.

```bash
sqlite3 HelloWorld.sqlite3 "
create table posts(id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name VARCHAR NOT NULL);
insert into posts values(1, 'First Post');
insert into posts values(2, 'Second Post');
select * from posts;"
```

## Install dependencies

First, install the `vcpkg` package manager as is described [here](building/tinyorm.mdx#vcpkg).

The `range-v3` and `tabulate` libraries are required dependencies because `TinyORM` uses them in header files, you have to install them before you can use `TinyORM`. The `tabulate` library is only needed in the `tom` migrations it's used by the `migrate:status` command.

There are two ways how to install the `range-v3` and `tabulate` libraries using `vcpkg`.

#### Using vcpkg.json <small>(manifest mode)</small> {#using-vcpkg-json}

Create a `vcpkg.json` file with the following content. `CMake` example below uses this method.

```bash
cd HelloWorld
vim vcpkg.json
```

```json
{
  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg/master/scripts/vcpkg.schema.json",
  "name": "tinyorm-hello-world",
  "version-semver": "0.1.0",
  "description": "HelloWorld example with TinyORM library.",
  "maintainers": "Silver Zachara <silver.zachara@gmail.com>",
  "supports": "!(uwp | arm | android | emscripten)",
  "dependencies": [
    "range-v3",
    "tabulate"
  ]
}
```

:::note
Only `CMake` via the `toolchain file` supports this method.
:::

#### Using vcpkg install <small>(manually)</small> {#using-vcpkg-install}

This method can be used with both `CMake` and `qmake`.

```bash
cd ../../vcpkg

vcpkg search range-v3
vcpkg search tabulate
vcpkg install range-v3 tabulate
vcpkg list
```

## Source code

Let's start in the `HelloWorld` project folder.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`cd ${applicationFolderPath(pwsh)}/HelloWorld/HelloWorld`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`cd ${applicationFolderPath(bash)}/HelloWorld/HelloWorld`}
</CodeBlock>
</TabItem>
</Tabs>

Create `main.cpp` source file.

```bash
vim main.cpp
```

:::tip
To paste a source code correctly in `vim`, press <kbd>Shift</kbd> + <kbd>p</kbd>.
:::

And paste the following code.

    #include <QDebug>

    #ifdef _WIN32
    #  include <qt_windows.h>
    #endif

    #include <orm/db.hpp>

    using Orm::DB;

    int main(int /*unused*/, char */*unused*/[])
    {
    #ifdef _WIN32
        SetConsoleOutputCP(CP_UTF8);
    //    SetConsoleOutputCP(1250);
    #endif

        // Ownership of a shared_ptr()
        auto manager = DB::create({
            {"driver",   "QSQLITE"},
            {"database", qEnvironmentVariable("DB_DATABASE", "HelloWorld.sqlite3")},
            {"check_database_exists", true},
        });

        auto posts = DB::select("select * from posts");

        while(posts.next())
            qDebug() << posts.value("id").toULongLong() << posts.value("name").toString();
    }

## Hello world with CMake

Create a folder for the `CMake` build.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`cd ..
mkdir HelloWorld-builds-cmake/build-debug\n
cd HelloWorld-builds-cmake/build-debug`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`cd ..
mkdir -p HelloWorld-builds-cmake/build-debug\n
cd HelloWorld-builds-cmake/build-debug`}
</CodeBlock>
</TabItem>
</Tabs>

### CMake project

Create `CMakeLists.txt` file with the following content.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-cmake'>
{`cmake_minimum_required(VERSION VERSION 3.20...3.23 FATAL_ERROR)\n
project(HelloWorld LANGUAGES CXX)\n
# build tree
list(APPEND CMAKE_PREFIX_PATH "${convertToCmakeEnvVariable(pwsh, applicationFolderPath(pwsh))}/TinyORM/TinyORM-builds-cmake/build-debug")\n
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)\n
add_executable(HelloWorld
  main.cpp
)\n
find_package(QT NAMES Qt6 Qt5 COMPONENTS Core REQUIRED)
find_package(Qt\${QT_VERSION_MAJOR} COMPONENTS Core REQUIRED)
find_package(TinyOrm 0.1.0 CONFIG REQUIRED)\n
target_link_libraries(HelloWorld
    PRIVATE
        Qt\${QT_VERSION_MAJOR}::Core
        TinyOrm::TinyOrm
)`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-cmake'>
{`cmake_minimum_required(VERSION VERSION 3.20...3.23 FATAL_ERROR)\n
project(HelloWorld LANGUAGES CXX)\n
# build tree
list(APPEND CMAKE_PREFIX_PATH "${convertToCmakeEnvVariable(bash, applicationFolderPath(bash))}/TinyORM/TinyORM-builds-cmake/build-debug")\n
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)\n
add_executable(HelloWorld
  main.cpp
)\n
find_package(QT NAMES Qt6 Qt5 COMPONENTS Core REQUIRED)
find_package(Qt\${QT_VERSION_MAJOR} COMPONENTS Core REQUIRED)
find_package(TinyOrm 0.1.0 CONFIG REQUIRED)\n
target_link_libraries(HelloWorld
    PRIVATE
        Qt\${QT_VERSION_MAJOR}::Core
        TinyOrm::TinyOrm
)`}
</CodeBlock>
</TabItem>
</Tabs>

### Build Hello world {#build-hello-world-cmake}

Now you are ready to configure `HelloWorld` `CMake` application.

```bash
cd ../HelloWorld-builds-cmake/build-debug
```

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`cmake.exe \`
-S "${applicationFolderPath(pwsh)}/HelloWorld/HelloWorld" \`
-B "${applicationFolderPath(pwsh)}/HelloWorld/HelloWorld-builds-cmake/build-debug" \`
-G 'Ninja' \`
-D CMAKE_BUILD_TYPE:STRING='Debug' \`
-D CMAKE_TOOLCHAIN_FILE:FILEPATH="${rootFolderPath(pwsh)}/vcpkg/scripts/buildsystems/vcpkg.cmake" \`
-D CMAKE_INSTALL_PREFIX:PATH="${rootFolderPath(pwsh)}/tmp/HelloWorld"`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`cmake \\
-S "${applicationFolderPath(bash)}/HelloWorld/HelloWorld" \\
-B "${applicationFolderPath(bash)}/HelloWorld/HelloWorld-builds-cmake/build-debug" \\
-G 'Ninja' \\
-D CMAKE_BUILD_TYPE:STRING='Debug' \\
-D CMAKE_TOOLCHAIN_FILE:FILEPATH="${rootFolderPath(bash)}/vcpkg/scripts/buildsystems/vcpkg.cmake" \\
-D CMAKE_INSTALL_PREFIX:PATH="${rootFolderPath(bash)}/tmp/TinyORM"`}
</CodeBlock>
</TabItem>
</Tabs>

And build.

```bash
cmake --build . --target all
```

### Execute Hello world {#execute-hello-world-cmake}

Do not forget to add `TinyOrm0d.dll` on the path on Windows and on the `LD_LIBRARY_PATH` on Linux, so `HelloWorld` application can find it during execution, as is described [here](building/tinyorm.mdx#tinyorm-on-path-cmake).

<Tabs groupId={shell} name='tinyorm-on-path'>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`$env:Path = "${applicationFolderPath(pwsh, false)}\\TinyORM\\TinyORM-builds-cmake\\build-debug;" + $env:Path`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`export LD_LIBRARY_PATH=${applicationFolderPath(bash)}/TinyORM/TinyORM-builds-cmake/build-debug\${PATH:+:}$PATH`}
</CodeBlock>
</TabItem>
</Tabs>

Create a symbolic link to the `HelloWorld.sqlite3` database inside the build folder. If you do not have enabled symbolic links without `Administrator` rights on your `Windows`, you can just simply copy the `HelloWorld.sqlite3` database or [`Allow symbolic links unprivileged`](building/tinyorm.mdx#allow-symbolic-links-unprivileged).

<Tabs groupId={shell} name='tinyorm-on-path'>
<TabItem value={pwsh} label={pwsh_label}>

```powershell
New-Item -ItemType SymbolicLink -Target ../../HelloWorld.sqlite3 -Name HelloWorld.sqlite3
# Or simply copy
Copy-Item ../../HelloWorld.sqlite3 .
```

</TabItem>
<TabItem value={bash} label={bash_label}>

```bash
ln -s ../../HelloWorld.sqlite3 .
```

</TabItem>
</Tabs>

Execute `HelloWorld` example.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>

```powershell
.\HelloWorld.exe
```

</TabItem>
<TabItem value={bash} label={bash_label}>

```bash
./HelloWorld
```

</TabItem>
</Tabs>

The output will look like this.

```less
Executed prepared query (6ms, -1 results, 0 affected, tinyorm_default) : select * from posts
1 "First Post"
2 "Second Post"
```

## Hello world with qmake

Create a folder for the `qmake` build.

<Tabs groupId={shell}>
<TabItem value={pwsh} label={pwsh_label}>
<CodeBlock className='language-powershell'>
{`cd ${applicationFolderPath(pwsh)}/HelloWorld\n
mkdir HelloWorld-builds-qmake`}
</CodeBlock>
</TabItem>
<TabItem value={bash} label={bash_label}>
<CodeBlock className='language-bash'>
{`cd ${applicationFolderPath(bash)}/HelloWorld\n
mkdir HelloWorld-builds-qmake`}
</CodeBlock>
</TabItem>
</Tabs>

The [`source code`](#source-code) is the same as for the `HelloWorld CMake` example.

### qmake project

Create `HelloWorld.pro` qmake file with the following content.

```bash
cd HelloWorld
vim HelloWorld.pro
```

:::tip
To paste a source code correctly in `vim`, press <kbd>Shift</kbd> + <kbd>p</kbd>.
:::

```qmake
QT *= core sql
QT -= gui

TEMPLATE = app

SOURCES += $$PWD/main.cpp

# Configure TinyORM library
include($$TINY_MAIN_DIR/TinyORM/qmake/TinyOrm.pri)

# vcpkg - range-v3
win32-msvc: \
    INCLUDEPATH += $$quote($$TINY_VCPKG_INSTALLED/x64-windows/include/)
mingw: \
    QMAKE_CXXFLAGS += -isystem $$shell_quote($$TINY_VCPKG_INSTALLED/x64-mingw-dynamic/include/)
unix:!macx: \
    QMAKE_CXXFLAGS += -isystem $$shell_quote($$TINY_VCPKG_INSTALLED/x64-linux/include/)
```

:::caution
The exact [folders structure](building/tinyorm.mdx#folders-structure) is crucial in this example because the paths to the `TinyORM` source and build folders are relative.
:::

:::tip
On Linux `-isystem` marks the directory as a system directory, it prevents warnings.

On Windows you can use `QMAKE_CXXFLAGS_WARN_ON = -external:anglebrackets -external:W0`, it applies a warning level 0 to the angel bracket includes; `#include <file>`.
:::

#### Configure using .qmake.conf

Create `.qmake.conf` in the `HelloWorld` project root folder with the following content.

```qmake
TINY_MAIN_DIR = $$clean_path($$PWD/../../TinyORM)
# Name of this qmake variable is crucial
TINYORM_BUILD_TREE = $$quote($$TINY_MAIN_DIR/TinyOrm-builds-qmake/build-TinyOrm-Desktop_Qt_6_3_1_MSVC2019_64bit-Debug)
# vcpkg - range-v3
TINY_VCPKG_INSTALLED = $$clean_path($$PWD/../../../vcpkg/installed)
```

:::info
Configuring with the `.qmake.conf` file has one big advantage that is that you do not have to modify the project files.
:::

### Build Hello world {#build-hello-world-qmake}

:::tip
I recommend creating a new `Session` in the `QtCreator IDE` as is described [here](building/tinyorm.mdx#open-qtcreator-ide).
:::

Now you can open the `HelloWorld.pro` project in the `QtCreator IDE`.

This will open the `Configure Project` tab, select some kit and update build folder paths to meet our [folders structure](building/tinyorm.mdx#folders-structure) or like you want.

<img src={require('./assets/img/hello-world/qmake-configure_project.png').default}
    alt='HelloWorld - QtCreator - Configure Project' width='760' />

You are ready to configure build options, hit <kbd>Ctrl</kbd>+<kbd>5</kbd> to open `Project Settings` tab and select `Build` in the left sidebar to open the `Build Settings`, it should look similar to the following picture.

<img src={require('./assets/img/hello-world/qmake-build_settings.png').default}
    className='no-blurry' alt='HelloWorld - QtCreator - Build Settings' width='760' />

Disable `QML debugging and profiling` and `Qt Quick Compiler`, they are not used.

In the left sidebar open `Dependencies` and check `TinyOrm` and `Synchronize configuration`, this setting ensures that the current project will be rebuilt correctly when the `TinyORM` library source code changes.

Everything is ready to build, you can press <kbd>Ctrl</kbd>+<kbd>b</kbd> to build the project.

### Execute Hello world {#execute-hello-world-qmake}

The `QtCreator` takes care about all the necessary configuration, sets up the build environment correctly and also prepends dependency libraries on the path on Windows and on the `LD_LIBRARY_PATH` on Linux.

Only one thing you might want to change is to run the `HelloWorld` example in the new terminal window. To do so, hit <kbd>Ctrl</kbd>+<kbd>5</kbd> to open the `Project Settings` tab and select `Run` in the left sidebar to open the `Run Settings`, then in the `Run` section select the `Run in terminal` checkbox.

Create a symbolic link to the `HelloWorld.sqlite3` database inside the build folder. If you do not have enabled symbolic links without `Administrator` rights on your `Windows`, you can just simply copy the `HelloWorld.sqlite3` database or [`Allow symbolic links unprivileged`](building/tinyorm.mdx#allow-symbolic-links-unprivileged).

<Tabs groupId={shell} name='tinyorm-on-path'>
<TabItem value={pwsh} label={pwsh_label}>

```powershell
cd ../HelloWorld-builds-qmake/build-HelloWorld-Desktop_Qt_5_15_2_MSVC2019_64bit-Debug

New-Item -ItemType SymbolicLink -Target ../../HelloWorld.sqlite3 -Name HelloWorld.sqlite3
# Or simply copy
Copy-Item ../../HelloWorld.sqlite3 .
```

</TabItem>
<TabItem value={bash} label={bash_label}>

```bash
cd ../HelloWorld-builds-qmake/build-HelloWorld-Desktop_Qt_5_15_2_GCC_64bit-Debug

ln -s ../../HelloWorld.sqlite3 .
```

</TabItem>
</Tabs>

To execute the `HelloWorld` example press <kbd>Ctrl</kbd> + <kbd>r</kbd>.

The output will look like this.

```less
Executed prepared query (6ms, -1 results, 0 affected, tinyorm_default) : select * from posts
1 "First Post"
2 "Second Post"
```