Added support for SQL Server

src/db/adapter.ts

@@ -0,0 +1,74 @@
+/**
+ * Database adapter interface
+ * Defines the contract for all database implementations (SQLite, SQL Server)
+ */
+export interface DbAdapter {
+  /**
+   * Initialize database connection
+   */
+  init(): Promise<void>;
+
+  /**
+   * Close database connection
+   */
+  close(): Promise<void>;
+
+  /**
+   * Execute a query and return all results
+   * @param query SQL query to execute
+   * @param params Query parameters
+   */
+  all(query: string, params?: any[]): Promise<any[]>;
+
+  /**
+   * Execute a query that modifies data
+   * @param query SQL query to execute
+   * @param params Query parameters
+   */
+  run(query: string, params?: any[]): Promise<{ changes: number, lastID: number }>;
+
+  /**
+   * Execute multiple SQL statements
+   * @param query SQL statements to execute
+   */
+  exec(query: string): Promise<void>;
+
+  /**
+   * Get database metadata
+   */
+  getMetadata(): { name: string, type: string, path?: string, server?: string, database?: string };
+
+  /**
+   * Get database-specific query for listing tables
+   */
+  getListTablesQuery(): string;
+
+  /**
+   * Get database-specific query for describing a table
+   * @param tableName Table name
+   */
+  getDescribeTableQuery(tableName: string): string;
+}
+
+// Import adapters using dynamic imports
+import { SqliteAdapter } from './sqlite-adapter.js';
+import { SqlServerAdapter } from './sqlserver-adapter.js';
+
+/**
+ * Factory function to create the appropriate database adapter
+ */
+export function createDbAdapter(type: string, connectionInfo: any): DbAdapter {
+  switch (type.toLowerCase()) {
+    case 'sqlite':
+      // For SQLite, if connectionInfo is a string, use it directly as path
+      if (typeof connectionInfo === 'string') {
+        return new SqliteAdapter(connectionInfo);
+      } else {
+        return new SqliteAdapter(connectionInfo.path);
+      }
+    case 'sqlserver':
+      return new SqlServerAdapter(connectionInfo);
+    default:
+      throw new Error(`Unsupported database type: ${type}`);
+  }
+}