Database Query Logging — Logging and Monitoring Database Queries

// TypeORM query logger
class PerformanceQueryLogger {
  constructor(options = {}) {
    this.slowQueryThreshold = options.slowQueryThreshold || 1000;
    this.maxQueryLength = options.maxQueryLength || 1000;
  }

  logQuery(query, parameters, duration) {
    const entry = {
      type: 'db_query',
      query: this.truncateQuery(query),
      parameters: this.sanitizeParameters(parameters),
      duration,
      timestamp: new Date().toISOString(),
      slow: duration > this.slowQueryThreshold
    };

    if (duration > this.slowQueryThreshold) {
      logger.warn(entry, 'Slow database query detected');
      metrics.timing('db.query.slow', duration, { query: query.split(' ')[0] });
    } else {
      logger.debug(entry);
    }

    metrics.timing('db.query', duration);
    metrics.increment('db.query.count', { operation: query.split(' ')[0].toLowerCase() });
  }

  truncateQuery(query) {
    return query.length > this.maxQueryLength
      ? query.slice(0, this.maxQueryLength) + '...'
      : query;
  }

  sanitizeParameters(params) {
    return params?.map(p => {
      if (typeof p === 'string' && p.length > 50) return '**TRUNCATED**';
      if (Buffer.isBuffer(p)) return '**BINARY**';
      return p;
    });
  }
}

// Sequelize logging configuration
const sequelize = new Sequelize({
  logging: (sql, timing) => {
    dbLogger.logQuery(sql, null, timing);
  },
  benchmark: true,
  logQueryParameters: true
});