connection-string-sqlite

SQLite Connection String Mode Sample

This sample demonstrates using JD.Efcpt.Build with connection string mode to reverse engineer Entity Framework Core models directly from a SQLite database file.

Features Demonstrated

• Connection String Mode: No DACPAC or SQL project required
• SQLite Provider: Using Microsoft.Data.Sqlite for schema reading
• Automatic Schema Fingerprinting: Detects schema changes and regenerates only when needed
• T4 Templates: Customizable code generation

Project Structure

connection-string-sqlite/
├── Database/
│   └── sample.db          # SQLite database file (created by setup script)
├── EntityFrameworkCoreProject/
│   ├── EntityFrameworkCoreProject.csproj
│   ├── efcpt-config.json
│   └── efcpt.renaming.json
├── setup-database.ps1     # Creates the sample database
└── README.md

Prerequisites

• .NET 10.0 SDK or later
• PowerShell (for setup script)

Getting Started

1. Create the Sample Database

Run the setup script to create a SQLite database with sample tables:

./setup-database.ps1

This creates Database/sample.db with the following schema:

• categories - Product categories
• products - Products with category references
• orders - Customer orders
• order_items - Order line items

2. Build the Project

dotnet build EntityFrameworkCoreProject

During build, JD.Efcpt.Build will:

1. Connect to the SQLite database using the connection string
2. Read the schema metadata
3. Generate Entity Framework Core models and DbContext
4. Output files to the Models/ directory

3. Verify Generated Files

After building, check EntityFrameworkCoreProject/Models/ for:

• SampleDbContext.cs - The DbContext
• Entity classes for each table

Configuration

Connection String Mode Properties

The .csproj file configures connection string mode:

<!-- Use connection string mode instead of DACPAC -->
<EfcptConnectionString>Data Source=$(MSBuildProjectDirectory)\..\Database\sample.db</EfcptConnectionString>
<EfcptProvider>sqlite</EfcptProvider>

Supported Providers

Provider	Value	Description
SQL Server	mssql	Microsoft SQL Server
PostgreSQL	postgres	PostgreSQL / CockroachDB
MySQL	mysql	MySQL / MariaDB
SQLite	sqlite	SQLite database files
Oracle	oracle	Oracle Database
Firebird	firebird	Firebird SQL
Snowflake	snowflake	Snowflake Data Cloud

Schema Changes

When you modify the database schema:

1. The fingerprint will detect the change
2. Next build will regenerate the models
3. Previous fingerprint is stored in obj/efcpt/.fingerprint

To force regeneration:

dotnet clean EntityFrameworkCoreProject
dotnet build EntityFrameworkCoreProject

Troubleshooting

"Database file not found"

Ensure you've run setup-database.ps1 first to create the sample database.

Models not regenerating

Delete the fingerprint file to force regeneration:

rm EntityFrameworkCoreProject/obj/efcpt/.fingerprint