IMPROVEMENT: added a another allowed keyword to inspect schema

sys/sys.php

@@ -5,23 +5,80 @@
 *     
 *       
 */
-function sql_read($query) {
+
+function get_db_connection($db_host = null, $db_user = null, $db_pass = null, $db_name = null) {
     global $db;
-      if (!isset($db) || is_null($db)) $db = new PDO("mysql:host=".DB_HOST.";",DB_USER,DB_PASS);
-      $stmt = $db->prepare($query);
-        if ($stmt->execute() === false) return ["status" => "error", "query"=>$query];
-        return $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+    // If custom credentials or a custom DB are provided, create a fresh, temporary connection
+    if ($db_host !== null || $db_user !== null || $db_pass !== null || $db_name !== null) {
+        $host = $db_host ?? DB_HOST;
+        $user = $db_user ?? DB_USER;
+        $pass = $db_pass ?? DB_PASS;
+        $name = $db_name ?? (defined('DB_NAME') ? DB_NAME : '');
+
+        $dsn_base = "mysql:host=" . $host . ";";
+        $dsn_full = $dsn_base . (!empty($name) ? "dbname=" . $name . ";" : "");
+
+        try {
+            return new PDO($dsn_full, $user, $pass);
+        } catch (PDOException $e) {
+            // MySQL Error 1049 is "Unknown database". If caught, fallback to connection without DB.
+            if (strpos($e->getMessage(), '1049') !== false) {
+                return new PDO($dsn_base, $user, $pass);
+            }
+            throw $e; // Re-throw if it's a real connection/auth issue
+        }
+    }
+
+    // Otherwise, use or initialize the global connection using constants
+    if (!isset($db) || is_null($db)) {
+        $dsn_base = "mysql:host=" . DB_HOST . ";";
+        $name = defined('DB_NAME') ? DB_NAME : '';
+        $dsn_full = $dsn_base . (!empty($name) ? "dbname=" . $name . ";" : "");
+
+        try {
+            $db = new PDO($dsn_full, DB_USER, DB_PASS);
+        } catch (PDOException $e) {
+            if (strpos($e->getMessage(), '1049') !== false) {
+                $db = new PDO($dsn_base, DB_USER, DB_PASS);
+            } else {
+                throw $e;
+            }
+        }
+    }
+    return $db;
 }
-function sql_write($query) {
-    global $db;
-      if (!isset($db) || is_null($db)) $db = new PDO("mysql:host=".DB_HOST.";",DB_USER,DB_PASS);
-      $stmt = $db->prepare($query);
-        if ($stmt->execute() === false) die ("sql error: $query");
-        return $stmt->rowCount();
+
+function sql_read($query, $db_host = null, $db_user = null, $db_pass = null, $db_name = null) {
+    $pdo = get_db_connection($db_host, $db_user, $db_pass, $db_name);
+    $stmt = $pdo->prepare($query);
+
+    if ($stmt->execute() === false) {
+        return ["status" => "error", "query" => $query];
+    }
+    return $stmt->fetchAll(PDO::FETCH_ASSOC);
 }
-function sql($query) {
-    if (strpos($query, "SELECT ") === 0) return sql_read($query);
-      else return sql_write($query);
+
+function sql_write($query, $db_host = null, $db_user = null, $db_pass = null, $db_name = null) {
+    $pdo = get_db_connection($db_host, $db_user, $db_pass, $db_name);
+    $stmt = $pdo->prepare($query);
+
+    if ($stmt->execute() === false) {
+        die("sql error: $query");
+    }
+    return $stmt->rowCount();
+}
+
+function sql($query, $db_host = null, $db_user = null, $db_pass = null, $db_name = null) {
+	if (
+		stripos(trim($query), "SHOW") === 0 
+		|| stripos(trim($query), "DESCRIBE") === 0
+		|| stripos(trim($query), "SELECT") === 0
+	) {
+        return sql_read($query, $db_host, $db_user, $db_pass, $db_name);
+    } else {
+        return sql_write($query, $db_host, $db_user, $db_pass, $db_name);
+    }
 }