@supercat1337/mysql-schema-parser

A library for parsing and working with MySQL database schema metadata.

Installation

npm install @supercat1337/mysql-schema-parser

Usage

import fs from 'node:fs';
import path from 'node:path';
import * as url from 'url';
import { parseMySQLSchema } from '@supercat1337/mysql-schema-parser';

const __dirname = url.fileURLToPath(new URL('.', import.meta.url));

// Parse schema from JSON file
const db = parseMySQLSchema(
    JSON.parse(fs.readFileSync(path.join(__dirname, 'data.json'), 'utf-8'))
);

console.log(db);

API Reference

Main Functions

parseMySQLSchema(schema: ColumnMetadataRaw[]): MySQLDatabase

Parses MySQL schema metadata into a structured MySQLDatabase object.

enrichWithStatistics(db: MySQLDatabase, indexes: IndexStatisticsRaw[]): void

Adds index statistics (from INFORMATION_SCHEMA.STATISTICS) to an existing MySQLDatabase object.
Enables advanced index analysis and improved CREATE TABLE generation (composite keys, FULLTEXT, SPATIAL, etc.).

Classes

MySQLDatabase

• ... (existing methods)
• loadIndexStatistics(indexesStats: IndexStatisticsRaw[]): void – internal, used by enrichWithStatistics.

MySQLTable

• ... (existing methods)
• addIndexStatistics(idxRaw: IndexStatisticsRaw): void – adds index info.
• getIndexes(): Map<string, IndexStatistics[]> – returns all indexes.
• getIndex(indexName: string): IndexStatistics[] | null – returns index columns.
• getIndexCardinality(indexName: string): number | null – returns cardinality.
• getPrimaryKey(): string[] | null – returns an array of primary key column names (ordered) or null if none.

MySQLTableColumn

• ... (unchanged)

Types

• IndexStatisticsRaw – raw index metadata from INFORMATION_SCHEMA.STATISTICS.
• IndexStatistics – normalized camelCase version.

Example with Statistics

import { parseMySQLSchema, enrichWithStatistics } from '@supercat1337/mysql-schema-parser';

const columns = await db.query(
    `SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'mydb'`
);
const dbSchema = parseMySQLSchema(columns);

const indexes = await db.query(
    `SELECT * FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = 'mydb'`
);
enrichWithStatistics(dbSchema, indexes);

const usersTable = dbSchema.tables.get('users');
console.log(usersTable.getPrimaryKey()); // '["id"]'
console.log(usersTable.getIndexCardinality('idx_email')); // e.g. 15234

// Generate CREATE TABLE with composite indexes and special types
console.log(usersTable.generateCreateTableQuery());

Features

• Parse raw MySQL schema metadata into structured objects
• Generate CREATE TABLE statements from metadata
• Type-safe access to database schema information
• Comprehensive column metadata representation
• Helper methods for common column checks (PK, nullable, etc.)

License

MIT