#MySQL exporter documentation

#Overview

MySQLExporter Convert the JSON Schema generated by schema-dsl into MySQL DDL statements, including CREATE TABLE and index creation statements.

#Core functions

• ✅ Generate CREATE TABLE DDL statement
• ✅ Automatic type mapping (JSON Schema → MySQL)
• ✅Support NOT NULL, DEFAULT, COMMENT
• ✅ Automatically detect primary keys
• ✅ Generate index DDL
• ✅ Configurable storage engine and character set

#quick start

import { s, exporters } from 'schema-dsl/pure';

// 1. Define Schema
const userSchema = s({
  id: 'string!',
  username: 'string:3-32!',
  email: 'email!',
  age: 'number:18-120',
  status: 'active|inactive'
});

// 2. Create exporter
const exporter = new exporters.MySQLExporter();

// 3. Export to MySQL DDL
const ddl = exporter.export('users', userSchema);
console.log(ddl);

Output:

CREATE TABLE `users` (
  `id` VARCHAR(255) NOT NULL,
  `username` VARCHAR(32) NOT NULL,
  `email` VARCHAR(255) NOT NULL,
  `age` DOUBLE NULL,
  `status` VARCHAR(255) NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

#API reference

#Constructor

new MySQLExporter(options)

Parameters:

#method

#export(tableName, jsonSchema)

Generate a MySQL CREATE TABLE statement.

const ddl = exporter.export('users', userSchema);

Parameters:

• tableName (string): table name
• jsonSchema (Object): JSON Schema object (must be of object type)

Return Value:

• string: MySQL DDL statement

#generateIndex(tableName, columnName, options)

Generate index creation statements.

const indexDdl = exporter.generateIndex('users', 'email', { unique: true });
console.log(indexDdl);
// CREATE UNIQUE INDEX `idx_users_email` ON `users` (`email`);

Parameters:

• tableName (string): table name
• columnName (string): column name
• options.name (string): index name (optional, default idx_table_column)
• options.unique (boolean): Whether the index is unique (default false)

#MySQLExporter.export(tableName, jsonSchema) (static method)

Fast export without instantiation.

const ddl = exporters.MySQLExporter.export('users', userSchema);

#Configuration options

#storage engine

//Use MyISAM engine
const exporter = new exporters.MySQLExporter({
  engine: 'MyISAM'
});

#Character set configuration

// Use utf8 character set
const exporter = new exporters.MySQLExporter({
  charset: 'utf8',
  collate: 'utf8_general_ci'
});

#Complete example

#User table DDL generation

import { s, exporters } from 'schema-dsl/pure';

//Define user Schema (with description)
const userSchema = s({
  id: 'string!',
  username: s('string:3-32!').description('User login name'),
  email: s('email!').description('User Email'),
  password: 'string:8-64!',
  age: 'number:0-150',
  status: 'active|inactive|banned',
  createdAt: 'datetime!'
});

// Generate DDL
const exporter = new exporters.MySQLExporter();
const ddl = exporter.export('users', userSchema);

console.log(ddl);

// Generate index
console.log(exporter.generateIndex('users', 'email', { unique: true }));
console.log(exporter.generateIndex('users', 'username', { unique: true }));
console.log(exporter.generateIndex('users', 'status'));

Output:

CREATE TABLE `users` (
  `id` VARCHAR(255) NOT NULL,
  `username` VARCHAR(32) NOT NULL COMMENT 'User login name',
  `email` VARCHAR(255) NOT NULL COMMENT 'User Email',
  `password` VARCHAR(64) NOT NULL,
  `age` DOUBLE NULL,
  `status` VARCHAR(255) NULL,
  `createdAt` DATETIME NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE UNIQUE INDEX `idx_users_email` ON `users` (`email`);
CREATE UNIQUE INDEX `idx_users_username` ON `users` (`username`);
CREATE INDEX `idx_users_status` ON `users` (`status`);

#type mapping

#constraint mapping

#Primary key detection

The exporter automatically detects the following fields as primary keys:

1. Field named id
2. Field named _id

If these fields exist, PRIMARY KEY constraints are automatically added.

#Export restrictions

⚠️ IMPORTANT: MySQL has limited support for constraints.

Features not supported by MySQL:

• ❌ Regular expression constraints (pattern)
• ❌ Numerical range constraints (minimum/maximum)
• ❌ Enumeration CHECK constraints (exported as normal VARCHAR)
• ❌ Minimum string length (minLength)
• ❌ Conditional validation logic (s.match(), s.if())

Detailed instructions: Please read Export restrictions document

#Related documents

• Database Export Guide
• MongoDB Exporter
• PostgreSQL Exporter
• TypeConverter
• Export restrictions ⚠️

#Corresponding sample file

Example entry: mysql-exporter.ts Description: Overrides export() generation of DDL, primary key detection, and generateIndex() generation of normal/unique indexes.