diff --git a/01/koneksi.php b/01/koneksi.php
index 35eeb05..e5998fe 100644
--- a/01/koneksi.php
+++ b/01/koneksi.php
@@ -1,15 +1,46 @@
 <?php
-$host = getenv('DB_HOST') ?: 'localhost';
-$user = getenv('DB_USER') ?: 'root';
-$pass = getenv('DB_PASSWORD');
-$pass = ($pass === false) ? '' : $pass;
-$db   = getenv('DB_NAME_01') ?: getenv('DB_NAME_SPBU') ?: getenv('DB_NAME') ?: 'spbu_db';
-$port = (int)(getenv('DB_PORT') ?: 3306);
+mysqli_report(MYSQLI_REPORT_OFF);
 
-$conn = new mysqli($host, $user, $pass, $db, $port);
+function env_value($keys, $default = null) {
+    foreach ($keys as $key) {
+        $value = getenv($key);
+        if ($value !== false && $value !== '') {
+            return $value;
+        }
+    }
+    return $default;
+}
 
-if ($conn->connect_error) {
-    die("Koneksi database gagal: " . $conn->connect_error);
+$explicitHost = env_value(['DB_HOST', 'MYSQL_HOST', 'MARIADB_HOST', 'DATABASE_HOST']);
+$user = env_value(['DB_USER', 'MYSQL_USER', 'MARIADB_USER', 'DATABASE_USER'], 'root');
+$pass = env_value(['DB_PASSWORD', 'MYSQL_PASSWORD', 'MARIADB_PASSWORD', 'DATABASE_PASSWORD'], '');
+$db   = env_value(['DB_NAME_01', 'DB_NAME_SPBU', 'DB_NAME', 'MYSQL_DATABASE', 'MARIADB_DATABASE', 'DATABASE_NAME'], 'spbu_db');
+$port = (int) env_value(['DB_PORT', 'MYSQL_PORT', 'MARIADB_PORT', 'DATABASE_PORT'], 3306);
+
+$hosts = $explicitHost ? [$explicitHost] : [];
+if (file_exists('/.dockerenv')) {
+    $hosts = array_merge($hosts, ['mysql', 'mariadb', 'database', 'db']);
+}
+$hosts[] = 'localhost';
+$hosts[] = '127.0.0.1';
+$hosts = array_values(array_unique($hosts));
+
+$conn = null;
+$lastError = '';
+
+foreach ($hosts as $host) {
+    $candidate = mysqli_init();
+    $candidate->options(MYSQLI_OPT_CONNECT_TIMEOUT, 3);
+    if (@$candidate->real_connect($host, $user, $pass, $db, $port)) {
+        $conn = $candidate;
+        break;
+    }
+    $lastError = $candidate->connect_error ?: mysqli_connect_error();
+}
+
+if (!$conn) {
+    http_response_code(500);
+    die("Koneksi database gagal. Host dicoba: " . implode(', ', $hosts) . ". Error: " . $lastError);
 }
 
 $conn->set_charset("utf8mb4");
diff --git a/02/koneksi.php b/02/koneksi.php
index a1441b8..a4f60f1 100644
--- a/02/koneksi.php
+++ b/02/koneksi.php
@@ -1,15 +1,46 @@
 <?php
-$host = getenv('DB_HOST') ?: 'localhost';
-$user = getenv('DB_USER') ?: 'root';
-$pass = getenv('DB_PASSWORD');
-$pass = ($pass === false) ? '' : $pass;
-$db   = getenv('DB_NAME_02') ?: getenv('DB_NAME_WEBGIS2') ?: getenv('DB_NAME') ?: 'webgis2';
-$port = (int)(getenv('DB_PORT') ?: 3306);
+mysqli_report(MYSQLI_REPORT_OFF);
 
-$conn = new mysqli($host, $user, $pass, $db, $port);
+function env_value($keys, $default = null) {
+    foreach ($keys as $key) {
+        $value = getenv($key);
+        if ($value !== false && $value !== '') {
+            return $value;
+        }
+    }
+    return $default;
+}
 
-if ($conn->connect_error) {
-    die("Koneksi database gagal: " . $conn->connect_error);
+$explicitHost = env_value(['DB_HOST', 'MYSQL_HOST', 'MARIADB_HOST', 'DATABASE_HOST']);
+$user = env_value(['DB_USER', 'MYSQL_USER', 'MARIADB_USER', 'DATABASE_USER'], 'root');
+$pass = env_value(['DB_PASSWORD', 'MYSQL_PASSWORD', 'MARIADB_PASSWORD', 'DATABASE_PASSWORD'], '');
+$db   = env_value(['DB_NAME_02', 'DB_NAME_WEBGIS2', 'DB_NAME', 'MYSQL_DATABASE', 'MARIADB_DATABASE', 'DATABASE_NAME'], 'webgis2');
+$port = (int) env_value(['DB_PORT', 'MYSQL_PORT', 'MARIADB_PORT', 'DATABASE_PORT'], 3306);
+
+$hosts = $explicitHost ? [$explicitHost] : [];
+if (file_exists('/.dockerenv')) {
+    $hosts = array_merge($hosts, ['mysql', 'mariadb', 'database', 'db']);
+}
+$hosts[] = 'localhost';
+$hosts[] = '127.0.0.1';
+$hosts = array_values(array_unique($hosts));
+
+$conn = null;
+$lastError = '';
+
+foreach ($hosts as $host) {
+    $candidate = mysqli_init();
+    $candidate->options(MYSQLI_OPT_CONNECT_TIMEOUT, 3);
+    if (@$candidate->real_connect($host, $user, $pass, $db, $port)) {
+        $conn = $candidate;
+        break;
+    }
+    $lastError = $candidate->connect_error ?: mysqli_connect_error();
+}
+
+if (!$conn) {
+    http_response_code(500);
+    die("Koneksi database gagal. Host dicoba: " . implode(', ', $hosts) . ". Error: " . $lastError);
 }
 
 $conn->set_charset("utf8mb4");
diff --git a/04/koneksi.php b/04/koneksi.php
index 2bf9b3d..e6f778b 100644
--- a/04/koneksi.php
+++ b/04/koneksi.php
@@ -1,15 +1,46 @@
 <?php
-$host = getenv('DB_HOST') ?: 'localhost';
-$user = getenv('DB_USER') ?: 'root';
-$pass = getenv('DB_PASSWORD');
-$pass = ($pass === false) ? '' : $pass;
-$db   = getenv('DB_NAME_04') ?: getenv('DB_NAME_SPBU') ?: getenv('DB_NAME') ?: 'spbu_db';
-$port = (int)(getenv('DB_PORT') ?: 3306);
+mysqli_report(MYSQLI_REPORT_OFF);
 
-$conn = new mysqli($host, $user, $pass, $db, $port);
+function env_value($keys, $default = null) {
+    foreach ($keys as $key) {
+        $value = getenv($key);
+        if ($value !== false && $value !== '') {
+            return $value;
+        }
+    }
+    return $default;
+}
 
-if ($conn->connect_error) {
-    die("Koneksi database gagal: " . $conn->connect_error);
+$explicitHost = env_value(['DB_HOST', 'MYSQL_HOST', 'MARIADB_HOST', 'DATABASE_HOST']);
+$user = env_value(['DB_USER', 'MYSQL_USER', 'MARIADB_USER', 'DATABASE_USER'], 'root');
+$pass = env_value(['DB_PASSWORD', 'MYSQL_PASSWORD', 'MARIADB_PASSWORD', 'DATABASE_PASSWORD'], '');
+$db   = env_value(['DB_NAME_04', 'DB_NAME_SPBU', 'DB_NAME', 'MYSQL_DATABASE', 'MARIADB_DATABASE', 'DATABASE_NAME'], 'spbu_db');
+$port = (int) env_value(['DB_PORT', 'MYSQL_PORT', 'MARIADB_PORT', 'DATABASE_PORT'], 3306);
+
+$hosts = $explicitHost ? [$explicitHost] : [];
+if (file_exists('/.dockerenv')) {
+    $hosts = array_merge($hosts, ['mysql', 'mariadb', 'database', 'db']);
+}
+$hosts[] = 'localhost';
+$hosts[] = '127.0.0.1';
+$hosts = array_values(array_unique($hosts));
+
+$conn = null;
+$lastError = '';
+
+foreach ($hosts as $host) {
+    $candidate = mysqli_init();
+    $candidate->options(MYSQLI_OPT_CONNECT_TIMEOUT, 3);
+    if (@$candidate->real_connect($host, $user, $pass, $db, $port)) {
+        $conn = $candidate;
+        break;
+    }
+    $lastError = $candidate->connect_error ?: mysqli_connect_error();
+}
+
+if (!$conn) {
+    http_response_code(500);
+    die("Koneksi database gagal. Host dicoba: " . implode(', ', $hosts) . ". Error: " . $lastError);
 }
 
 $conn->set_charset("utf8mb4");
diff --git a/05/koneksi.php b/05/koneksi.php
index 244c1bf..657db67 100644
--- a/05/koneksi.php
+++ b/05/koneksi.php
@@ -1,16 +1,49 @@
 <?php
-$host = getenv('DB_HOST') ?: 'localhost';
-$user = getenv('DB_USER') ?: 'root';
-$pass = getenv('DB_PASSWORD');
-$pass = ($pass === false) ? '' : $pass;
-$db   = getenv('DB_NAME_05') ?: getenv('DB_NAME_UAS') ?: getenv('DB_NAME') ?: 'webgis_uas';
-$port = (int)(getenv('DB_PORT') ?: 3306);
+mysqli_report(MYSQLI_REPORT_OFF);
 
-$conn = new mysqli($host, $user, $pass, $db, $port);
+function env_value($keys, $default = null) {
+    foreach ($keys as $key) {
+        $value = getenv($key);
+        if ($value !== false && $value !== '') {
+            return $value;
+        }
+    }
+    return $default;
+}
 
-if ($conn->connect_error) {
+$explicitHost = env_value(['DB_HOST', 'MYSQL_HOST', 'MARIADB_HOST', 'DATABASE_HOST']);
+$user = env_value(['DB_USER', 'MYSQL_USER', 'MARIADB_USER', 'DATABASE_USER'], 'root');
+$pass = env_value(['DB_PASSWORD', 'MYSQL_PASSWORD', 'MARIADB_PASSWORD', 'DATABASE_PASSWORD'], '');
+$db   = env_value(['DB_NAME_05', 'DB_NAME_UAS', 'DB_NAME', 'MYSQL_DATABASE', 'MARIADB_DATABASE', 'DATABASE_NAME'], 'webgis_uas');
+$port = (int) env_value(['DB_PORT', 'MYSQL_PORT', 'MARIADB_PORT', 'DATABASE_PORT'], 3306);
+
+$hosts = $explicitHost ? [$explicitHost] : [];
+if (file_exists('/.dockerenv')) {
+    $hosts = array_merge($hosts, ['mysql', 'mariadb', 'database', 'db']);
+}
+$hosts[] = 'localhost';
+$hosts[] = '127.0.0.1';
+$hosts = array_values(array_unique($hosts));
+
+$conn = null;
+$lastError = '';
+
+foreach ($hosts as $host) {
+    $candidate = mysqli_init();
+    $candidate->options(MYSQLI_OPT_CONNECT_TIMEOUT, 3);
+    if (@$candidate->real_connect($host, $user, $pass, $db, $port)) {
+        $conn = $candidate;
+        break;
+    }
+    $lastError = $candidate->connect_error ?: mysqli_connect_error();
+}
+
+if (!$conn) {
     http_response_code(500);
-    die(json_encode(["error" => "Koneksi database gagal: " . $conn->connect_error]));
+    die(json_encode([
+        "status" => "error",
+        "msg" => "Koneksi database gagal. Host dicoba: " . implode(', ', $hosts) . ". Error: " . $lastError
+    ]));
 }
 
 $conn->set_charset("utf8mb4");