import sql from 'mssql';
import { MSSQLConfig } from '../../types/database.types.js';
/**
* Database Connection Class
*
* Manages MSSQL database connections and provides basic query execution functionality
*/
export class DatabaseConnection {
private pool: sql.ConnectionPool | null = null;
private config: sql.config;
constructor() {
this.config = this.loadConfiguration();
}
/**
* Connect to database
*/
async connect(): Promise<void> {
try {
this.pool = new sql.ConnectionPool(this.config);
await this.pool.connect();
// Connection successful - no console output needed for MCP
} catch (error) {
// Use stderr for error output to avoid interfering with JSON-RPC
process.stderr.write(`Database connection failed: ${error}\n`);
throw error;
}
}
/**
* Disconnect from database
*/
async disconnect(): Promise<void> {
try {
if (this.pool) {
await this.pool.close();
this.pool = null;
// Disconnection successful - no console output needed for MCP
}
} catch (error) {
process.stderr.write(`Database disconnection failed: ${error}\n`);
throw error;
}
}
/**
* Execute SQL query
*/
async executeQuery(query: string): Promise<sql.IResult<any>> {
if (!this.pool) {
throw new Error('Database not connected');
}
try {
const request = this.pool.request();
const result = await request.query(query);
return result;
} catch (error) {
process.stderr.write(`Query execution failed: ${error}\n`);
throw error;
}
}
/**
* Test database connection
*/
async testConnection(): Promise<boolean> {
try {
if (!this.pool) {
await this.connect();
}
const result = await this.executeQuery('SELECT 1 as test');
return result.recordset.length > 0;
} catch (error) {
process.stderr.write(`Connection test failed: ${error}\n`);
return false;
}
}
/**
* Load database configuration from environment variables
*/
private loadConfiguration(): sql.config {
return {
server: process.env.DB_SERVER || 'localhost',
port: parseInt(process.env.DB_PORT || '1433'),
database: process.env.DB_DATABASE || '',
user: process.env.DB_USER || '',
password: process.env.DB_PASSWORD || '',
options: {
encrypt: process.env.DB_ENCRYPT === 'true',
trustServerCertificate: process.env.DB_TRUST_SERVER_CERTIFICATE === 'true',
},
connectionTimeout: parseInt(process.env.DB_CONNECTION_TIMEOUT || '30000'),
requestTimeout: parseInt(process.env.DB_REQUEST_TIMEOUT || '30000'),
pool: {
min: parseInt(process.env.DB_POOL_MIN || '2'),
max: parseInt(process.env.DB_POOL_MAX || '10'),
idleTimeoutMillis: parseInt(process.env.DB_POOL_IDLE_TIMEOUT || '30000'),
},
};
}
/**
* Get current configuration
*/
getConfiguration(): sql.config {
return { ...this.config };
}
/**
* Get connection pool status
*/
getPoolStatus() {
if (!this.pool) {
return { connected: false, pool: null };
}
return {
connected: this.pool.connected,
connecting: this.pool.connecting,
pool: {
size: this.pool.size,
available: this.pool.available,
pending: this.pool.pending,
borrowed: this.pool.borrowed,
},
};
}
}
