Oracle client (#65)

* Update README.md

* Update README.md

* Update README.md

* handle oracle credentials

Author: Sylvestre

README.md

@@ -1,6 +1,6 @@
 # @observablehq/database-proxy
 
-The database proxy is a simple Node.js webserver that accepts secure requests from your Observable notebooks, and proxies queries to a PostgreSQL or MySQL database — one that is not necessarily exposed to the web. You can use the database proxy to securely connect to databases on your local computer, on an intranet or within a VPN.
+The database proxy is a simple Node.js webserver that accepts secure requests from your Observable notebooks, and proxies queries to a PostgreSQL, MySQL, Snowflake, SQL Server, Databricks or Oracle database — one that is not necessarily exposed to the web. You can use the database proxy to securely connect to databases on your local computer, on an intranet or within a VPN.
 
 ## Installation
 
@@ -11,6 +11,21 @@ Install the database proxy locally or globally with `npm` or `yarn`:
   yarn global add @observablehq/database-proxy
 ```
 
+### Installing for Oracle Databases
+
+To use the Oracle database client, you will also need to install the `oracledb` npm library with `npm` or `yarn`: 
+```
+  npm install -g oracledb
+  yarn global add oracldeb
+```
+#### Architecture 
+Node-oracledb is an [add-on](https://nodejs.org/api/addons.html) available as C source code. Pre-built binaries are available as a convenience for common architectures (Windows 64-bit, Linux x86_64, and macOS (Intel x86)). For other architectures (i.e `macOS (ARM64)`), you will need to build from the source code as described [here](https://node-oracledb.readthedocs.io/en/latest/user_guide/installation.html#quick-start-node-oracledb-installation). 
+
+#### Oracle Client Library
+One of the Oracle Client libraries version 21, 19, 18, 12, or 11.2 needs to be installed in your operating system library search path such as `PATH` on Windows or `LD_LIBRARY_PATH` on Linux. On macOS link the libraries to `/usr/local/lib`.
+
+For more information see [node-oracldb](https://node-oracledb.readthedocs.io/en/latest/user_guide/installation.html) documentation.
+
 ## Running the database proxy
 
 Usage: `observable-database-proxy <command> <name> [options]`

lib/commands.js

@@ -23,6 +23,8 @@ export async function add(argv, reset = false) {
   let token;
   let server_host;
   let path;
+  let username;
+  let password;
 
   if (config && config[name] && !reset)
     exit(`A database proxy for "${name}" already exists`);
@@ -59,32 +61,45 @@ export async function add(argv, reset = false) {
 
   // DB credentials
   if (!reset) {
-    // Databricks credentials
-    if (decoded.type === "databricks") {
-      token = await question("Databricks token: ");
-      server_host = await question("Databricks server host: ");
-      path = await question("Databricks path: ");
-    } else {
-      url = await question(
-        "PostgreSQL, MySQL, or Snowflake Database URL (including username and password): "
-      );
+    switch (decoded.type) {
+      case "databricks":
+        token = await question("Databricks token: ");
+        server_host = await question("Databricks server host: ");
+        path = await question("Databricks path: ");
+        break;
+      case "oracle":
+        username = await question("Username: ");
+        password = await question("Password: ");
+        url = await question("Connection String: ");
+        break;
+      default:
+        url = await question(
+          "PostgreSQL, MySQL, or Snowflake Database URL (including username and password): "
+        );
     }
   }
 
   rl.close();
 
   if (!config) config = {};
-  if (decoded.type === "databricks") {
-    config[name] = {
-      name,
-      secret,
-      token,
-      server_host,
-      path,
-    };
-  } else {
-    config[name] = {name, secret, url};
-  }
+  config[name] =
+    decoded.type === "databricks"
+      ? {
+          name,
+          secret,
+          token,
+          server_host,
+          path,
+        }
+      : decoded.type === "oracle"
+      ? {
+          name,
+          secret,
+          username,
+          password,
+          url,
+        }
+      : {name, secret, url};
 
   writeConfig(config);