Merge pull request #18 from onozaty/16-add-mysql-support

Add MySQL support #16

Author: onozaty

.claude/settings.local.json

@@ -0,0 +1,12 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(find:*)",
+      "Bash(pnpm run test:*)",
+      "Bash(pnpm run lint:*)",
+      "Bash(pnpm run format:*)",
+      "WebFetch(domain:github.com)"
+    ],
+    "deny": []
+  }
+}

.devcontainer/docker-compose.yml

@@ -1,5 +1,3 @@
-version: "3.8"
-
 services:
   app:
     build:
@@ -9,7 +7,9 @@ services:
       - ../..:/workspaces:cached
       - app-node-modules:/workspaces/app/node_modules
     command: sleep infinity
-    network_mode: service:db
+    depends_on:
+      - db
+      - mysql
   db:
     image: postgres:latest
     restart: unless-stopped
@@ -19,6 +19,23 @@ services:
       POSTGRES_PASSWORD: db_password
       POSTGRES_USER: db_user
       POSTGRES_DB: sample
+    ports:
+      - 5432:5432
+
+  mysql:
+    image: mysql:latest
+    restart: unless-stopped
+    volumes:
+      - mysql-data:/var/lib/mysql
+      - ./mysql-init:/docker-entrypoint-initdb.d
+    environment:
+      MYSQL_ROOT_PASSWORD: root_password
+      MYSQL_DATABASE: sample
+      MYSQL_USER: db_user
+      MYSQL_PASSWORD: db_password
+    ports:
+      - 3306:3306
+
   pgadmin4:
     image: dpage/pgadmin4:latest
     ports:
@@ -33,7 +50,21 @@ services:
       PGADMIN_CONFIG_MASTER_PASSWORD_REQUIRED: "False"
     depends_on:
       - db
+
+  phpmyadmin:
+    image: phpmyadmin/phpmyadmin:latest
+    restart: unless-stopped
+    ports:
+      - 8081:80
+    environment:
+      PMA_HOST: mysql
+      PMA_USER: db_user
+      PMA_PASSWORD: db_password
+      MYSQL_ROOT_PASSWORD: root_password
+    depends_on:
+      - mysql
 volumes:
   postgres-data:
+  mysql-data:
   app-node-modules:
   pgadmin-data:

.devcontainer/mysql-init/01-grant-privileges.sql

@@ -0,0 +1,4 @@
+-- Grant required privileges to db_user for Prisma shadow database
+-- Based on: https://www.prisma.io/docs/orm/prisma-migrate/understanding-prisma-migrate/shadow-database#shadow-database-user-permissions
+GRANT CREATE, ALTER, DROP, REFERENCES, CREATE ROUTINE, ALTER ROUTINE ON *.* TO 'db_user'@'%';
+FLUSH PRIVILEGES;

.env.mysql

@@ -0,0 +1 @@
+DATABASE_URL="mysql://db_user:db_password@mysql:3306/sample"

.gitignore

@@ -1,5 +1,6 @@
 node_modules/
 dist/
 prisma/migrations/
+prisma-mysql/migrations/
 coverage/
 src/__fixtures__/**/migrations/

CLAUDE.md

@@ -25,13 +25,14 @@ Always run `pnpm run format` after editing code to ensure consistent formatting
 
 ## Architecture
 
-The codebase follows a clear separation of concerns with four main modules:
+The codebase follows a clear separation of concerns with five main modules:
 
 ### Core Flow
 1. **parser.ts** - Parses Prisma DMMF (Data Model Meta Format) into internal types
-2. **comment.ts** - Creates comment structures and handles diff logic
-3. **statement.ts** - Generates SQL `COMMENT ON` statements
-4. **generator.ts** - Main generator that orchestrates the process and handles file I/O
+2. **config.ts** - Handles configuration reading and validation
+3. **comment.ts** - Creates comment structures and handles diff logic
+4. **statement.ts** - Generates SQL `COMMENT ON` statements
+5. **generator.ts** - Main generator that orchestrates the process and handles file I/O
 
 ### Key Components
 
@@ -40,37 +41,48 @@ The codebase follows a clear separation of concerns with four main modules:
 - Filters only scalar and enum fields (ignores relations)
 - Maps Prisma names to database names using `@@map` directives
 
+**config.ts** (`src/config.ts`):
+- Defines the `Config` interface for all configuration options
+- Implements `readConfig` function to extract and validate configuration from GeneratorOptions
+- Handles parsing of targets, patterns, provider detection, and output directory resolution
+- Centralizes all configuration logic for better maintainability
+
 **comment.ts** (`src/comment.ts`):
-- Creates comment structures for tables and columns based on targets
+- Creates comment structures for tables and columns based on configuration
 - Implements diffing logic to generate only changed comments
-- Handles filtering via `ignorePattern` and `ignoreCommentPattern`
+- Accepts `Config` object instead of individual parameters for cleaner interface
 - Supports enum information injection into field comments
 
 **statement.ts** (`src/statement.ts`):
-- Generates PostgreSQL `COMMENT ON TABLE` and `COMMENT ON COLUMN` statements
+- Generates PostgreSQL and MySQL `COMMENT ON` statements
 - Handles comment escaping and multi-line comments with E-strings
-- Supports schema-qualified table names
+- Supports schema-qualified table names and multiple database providers
 
 **generator.ts** (`src/generator.ts`):
 - Entry point that implements Prisma's generator interface
+- Uses `readConfig` to obtain all configuration settings
 - Manages state persistence via `comments-latest.json`
 - Creates migration files with timestamped directories
-- Orchestrates the entire generation process
+- Orchestrates the entire generation process with improved separation of concerns
 
 ### State Management
 The generator maintains state between runs by storing the current comments in `prisma/migrations/comments-latest.json`. This enables differential generation - only creating migration files for changed comments.
 
 ### Configuration Options
+All configuration options are now centralized in `config.ts`:
 - `targets` - Select "table", "column", or both for comment generation
 - `ignorePattern` - Regex to exclude models by database name
 - `ignoreCommentPattern` - Regex to exclude comments by content
 - `includeEnumInFieldComment` - Add enum values to field comments
+- `provider` - Auto-detected database provider (PostgreSQL or MySQL)
+- `outputDir` - Parsed output directory from generator configuration
 
 ## Testing
 
 Tests use Vitest and are organized as:
-- Unit tests for each module (e.g., `comment.test.ts`)
+- Unit tests for each module (e.g., `comment.test.ts`, `config.test.ts`)
 - Integration tests for the generator (`generator.test.ts`)
+- Configuration testing with comprehensive coverage (`config.test.ts` - 17 test cases)
 - Snapshot testing for generated SQL output
 - Test fixtures in `src/__fixtures__/` with various schema scenarios
 

README.md

@@ -240,8 +240,24 @@ COMMENT ON COLUMN "products"."type" IS E'Product Type\nenum: enum_product_type(B
 ## Supported Databases
 
 - PostgreSQL
+- MySQL (Experimental)
 
-Other databases may be available, but the above is the only one checked.
+### MySQL Support (Experimental)
+
+MySQL support is currently experimental and we are seeking feedback. For MySQL, this generator uses stored procedures to manage column comments due to MySQL's specific syntax requirements for column comment updates.
+
+**Why Stored Procedures are Used:**
+MySQL requires the full column definition when updating column comments via `ALTER TABLE ... MODIFY COLUMN`. To handle this complexity, the generator creates a stored procedure (`prisma_update_column_comment`) that dynamically retrieves the current column definition from `information_schema` and safely applies the comment update.
+
+**Required MySQL Permissions:**
+- `CREATE ROUTINE` - Required to create stored procedures for column comments
+- `ALTER ROUTINE` - Required to modify stored procedures if needed
+
+The generated SQL includes:
+- Direct `ALTER TABLE` statements for table comments
+- Stored procedures for column comment updates (automatically created and cleaned up)
+
+Other databases may be available, but the above are the only ones tested.
 
 ## License
 

package.json

@@ -13,13 +13,17 @@
   "scripts": {
     "build": "rm -rf dist/ && node build.js",
     "prepare": "pnpm run build",
+    "typecheck": "tsc --noEmit",
     "format": "prettier --write src/**",
     "lint": "eslint 'src/**/*.ts' --ignore-pattern 'src/__fixtures__/**'",
     "test": "vitest run",
     "test:cov": "vitest run --coverage",
+    "db:init": "rm -rf prisma/migrations && prisma migrate reset --skip-generate",
     "db:migrate": "prisma migrate dev && prisma generate && pnpm run db:deploy",
-    "db:reset": "prisma migrate reset",
-    "db:deploy": "prisma migrate deploy"
+    "db:deploy": "prisma migrate deploy",
+    "db:init:mysql": "rm -rf prisma-mysql/migrations && dotenv -e .env.mysql -- prisma migrate reset --skip-generate --schema=prisma-mysql/schema.prisma",
+    "db:migrate:mysql": "dotenv -e .env.mysql -- prisma migrate dev --schema=prisma-mysql/schema.prisma && dotenv -e .env.mysql -- prisma generate --schema=prisma-mysql/schema.prisma && pnpm run db:deploy:mysql",
+    "db:deploy:mysql": "dotenv -e .env.mysql -- prisma migrate deploy --schema=prisma-mysql/schema.prisma"
   },
   "repository": {
     "type": "git",
@@ -42,6 +46,7 @@
     "@types/node": "^22.0.0",
     "@vitest/coverage-v8": "^3.2.0",
     "@vitest/eslint-plugin": "^1.2.1",
+    "dotenv-cli": "^8.0.0",
     "esbuild": "^0.25.5",
     "eslint": "^9.28.0",
     "globals": "^15.8.0",

pnpm-lock.yaml

@@ -0,0 +1,86 @@
+generator client {
+  provider        = "prisma-client-js"
+  previewFeatures = ["views"]
+}
+
+generator comments {
+  provider                  = "node ./dist/generator.cjs"
+  ignorePattern             = "_view$"
+  includeEnumInFieldComment = true
+}
+
+datasource db {
+  provider = "mysql"
+  url      = env("DATABASE_URL")
+}
+
+/// Product type enumeration
+enum ProductType {
+  BOOK
+  TOY
+  FASHION
+
+  @@map("enum_product_type")
+}
+
+/// Customer
+model Customer {
+  /// Customer ID
+  customerId Int      @id @default(autoincrement()) @map("customer_id")
+  /// Customer Name
+  name       String
+  /// e-mail
+  email      String   @unique
+  createdAt  DateTime @default(now()) @map("created_at")
+  sales      Sale[]
+
+  @@map("customers")
+}
+
+/// Product's information
+model Product {
+  /// Product ID
+  productId   Int         @id @default(autoincrement()) @map("product_id")
+  /// Product Name
+  name        String
+  /// Product Type
+  type        ProductType
+  /// Product Description
+  description String?
+  /// Price
+  price       Float
+  createdAt   DateTime    @default(now()) @map("created_at")
+  sales       Sale[]
+
+  @@map("products")
+}
+
+model Sale {
+  /// Sale ID
+  saleId     Int      @id @default(autoincrement()) @map("sale_id")
+  customer   Customer @relation(fields: [customerId], references: [customerId])
+  /// Customer ID
+  customerId Int      @map("customer_id")
+  product    Product  @relation(fields: [productId], references: [productId])
+  /// Product ID
+  productId  Int      @map("product_id")
+  /// Quantity
+  quantity   Int
+  /// Total Price
+  totalPrice Float    @map("total_price")
+  createdAt  DateTime @default(now()) @map("created_at")
+
+  @@map("sales")
+}
+
+/// Customer Sale Summary View
+view CustomerSaleSummaryView {
+  /// Customer ID
+  customerId         Int    @id @map("customer_id")
+  /// Customer Name
+  name               String
+  /// Total
+  totalPurchasePrice Int    @map("total_purchase_price")
+
+  @@map("customer_sale_summaries_view")
+}