diff --git a/extdbms/lib/Configs/App.php b/extdbms/lib/Configs/App.php
index f52ae68..b4a32f2 100644
--- a/extdbms/lib/Configs/App.php
+++ b/extdbms/lib/Configs/App.php
@@ -13,7 +13,6 @@ class App extends Core
     // .env 파일 로드
     $dotenv = Dotenv::createImmutable(ROOT_PATH);
     $dotenv->load();
-    DB::init(); // ✅ 여기서 초기화
     parent::__construct();
   }
 }
diff --git a/extdbms/lib/Core/Model.php b/extdbms/lib/Core/Model.php
index 2541529..00ef455 100644
--- a/extdbms/lib/Core/Model.php
+++ b/extdbms/lib/Core/Model.php
@@ -5,67 +5,17 @@ namespace lib\Core;
 use lib\Database\DB;
 use lib\Database\QueryBuilder;
 
-abstract class Model
+abstract class Model extends QueryBuilder
 {
-
-    private bool $_debug = false;
-    protected static QueryBuilder $queryBuilder;
-    public function __construct() {} //
+    public function __construct()
+    {
+        DB::init(); // ✅ 여기서 초기화
+        parent::__construct(DB::getPDO()); // QueryBuilder에 전달
+        parent::table($this->getTable());
+        parent::setDebug($_ENV['DATABASE_QUERY_DEBUG'] ?? $_SERVER['DATABASE_QUERY_DEBUG'] ?? false);
+    }
 
     abstract public function getTable(): string;
     abstract public function getPKField(): string;
     abstract public function getTitleField(): string;
-    final public function setDebug(bool $debug): void
-    {
-        $this->_debug = $debug;
-    }
-    final public function getDebug(): bool
-    {
-        return $this->_debug;
-    }
-
-    public static function query(): QueryBuilder
-    {
-        if (!isset(self::$queryBuilder)) {
-            self::$queryBuilder = new QueryBuilder(pdo: DB::getPDO()); // Assuming DB::getPDO() gives PDO instance
-        }
-        return self::$queryBuilder->table((new static())->getTable());
-    }
-
-    public static function all(): array
-    {
-        return self::query()->get();
-    }
-    public static function find($id): ?array
-    {
-        return self::query()->where((new static())->getPKField(), '=', $id)->first();
-    }
-    public static function where(string $column, string $operator = "", mixed $value = ""): QueryBuilder
-    {
-        return self::query()->where($column, $operator, $value);
-    }
-    public static function whereNotIn(string $column, array $values): QueryBuilder
-    {
-        return self::query()->whereNotIn($column, $values);
-    }
-    public static function orWhereIn(string $column, array $values): QueryBuilder
-    {
-        return self::query()->orWhereIn($column, $values);
-    }
-    public static function count(): int
-    {
-        return self::query()->count();
-    }
-    public static function insert(array $data): bool
-    {
-        return self::query()->insert($data);
-    }
-    public static function updateById($id, array $data): bool
-    {
-        return self::query()->where((new static())->getPKField(), '=', $id)->update($data);
-    }
-    public static function deleteById($id): bool
-    {
-        return self::query()->where((new static())->getPKField(), '=', $id)->delete();
-    }
 }
diff --git a/extdbms/lib/Database/DB.php b/extdbms/lib/Database/DB.php
index ecd2108..e0be95c 100644
--- a/extdbms/lib/Database/DB.php
+++ b/extdbms/lib/Database/DB.php
@@ -7,25 +7,22 @@ use PDO;
 
 class DB
 {
-  private static PDO $pdo;
+  private static ?PDO $pdo = null;
 
-  public static function init(): void
-  {
-    $driver  = $_ENV['DATABASE_DRIVER'] ?? $_SERVER['DATABASE_DRIVER'] ?? 'mysql';
-    $host    = $_ENV['DATABASE_HOST'] ?? $_SERVER['DATABASE_HOST'] ?? 'localhost';
-    $dbname  = $_ENV['DATABASE_DB'] ?? $_SERVER['DATABASE_DB'] ?? 'test';
-    $charset = $_ENV['DATABASE_CHARSET'] ?? $_SERVER['DATABASE_CHARSET'] ?? 'utf8';
-    $user    = $_ENV['DATABASE_ID'] ?? $_SERVER['DATABASE_ID'] ?? 'root';
-    $pass    = $_ENV['DATABASE_PASSWORD'] ?? $_SERVER['DATABASE_PASSWORD'] ?? '';
-    $dsn     = sprintf("%s:host=%s;dbname=%s;charset=%s", $driver, $host, $dbname, $charset);
-    self::$pdo = new \PDO($dsn, $user, $pass);
-    self::$pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
-  }
+  public static function init(): void {}
 
   public static function getPDO(): PDO
   {
-    if (!isset(self::$pdo)) {
-      throw new \Exception("PDO not initialized. Call DB::init() first.");
+    if (self::$pdo === null) {
+      $driver  = $_ENV['DATABASE_DRIVER'] ?? $_SERVER['DATABASE_DRIVER'] ?? 'mysql';
+      $host    = $_ENV['DATABASE_HOST'] ?? $_SERVER['DATABASE_HOST'] ?? 'localhost';
+      $dbname  = $_ENV['DATABASE_DB'] ?? $_SERVER['DATABASE_DB'] ?? 'test';
+      $charset = $_ENV['DATABASE_CHARSET'] ?? $_SERVER['DATABASE_CHARSET'] ?? 'utf8';
+      $user    = $_ENV['DATABASE_ID'] ?? $_SERVER['DATABASE_ID'] ?? 'root';
+      $pass    = $_ENV['DATABASE_PASSWORD'] ?? $_SERVER['DATABASE_PASSWORD'] ?? '';
+      $dsn     = sprintf("%s:host=%s;dbname=%s;charset=%s", $driver, $host, $dbname, $charset);
+      self::$pdo = new \PDO($dsn, $user, $pass);
+      self::$pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
     }
     return self::$pdo;
   }
diff --git a/extdbms/lib/Database/QueryBuilder.php b/extdbms/lib/Database/QueryBuilder.php
index c92967e..f1bf102 100644
--- a/extdbms/lib/Database/QueryBuilder.php
+++ b/extdbms/lib/Database/QueryBuilder.php
@@ -6,236 +6,168 @@ use PDO;
 
 class QueryBuilder
 {
-  private PDO $pdo;
-  private string $table = '';
-  private array $select = ['*'];
-  private array $where = [];
-  private array $bindings = [];
-  private array $order = [];
-  private ?int $limit = null;
-  private ?int $offset = null;
-  private array $joins = [];
+  private bool $_debug = false;
+  protected PDO $pdo;
+  protected string $latestQuery = "";
+  protected string $table = '';
+  protected array $select = ['*'];
+  protected array $where = [];
+  protected array $bindings = [];
+  protected array $order = [];
+  protected array $joins = [];
+  protected ?int $limit = null;
+  protected ?int $offset = null;
 
-  public function __construct(PDO $pdo)
+  protected function __construct(PDO $pdo)
   {
     $this->pdo = $pdo;
   }
-
+  final public function setDebug(bool $debug): void
+  {
+    $this->_debug = $debug;
+  }
+  final public function getLastQuery(): string
+  {
+    return $this->latestQuery;
+  }
   public function table(string $table): static
   {
     $this->table = $table;
     return $this;
   }
 
+  protected function buildSelectSql(): string
+  {
+    $sql = "SELECT " . implode(', ', $this->select) . " FROM {$this->table}";
+    // ⬇️ Join 처리 추가
+    if (!empty($this->joins)) {
+      $sql .= ' ' . implode(' ', $this->joins);
+    }
+    if (!empty($this->where)) {
+      $sql .= " WHERE " . $this->buildWhereSql();
+    }
+    if (!empty($this->order)) {
+      $sql .= " ORDER BY " . implode(', ', $this->order);
+    }
+    if ($this->limit !== null) {
+      $sql .= " LIMIT {$this->limit}";
+    }
+    if ($this->offset !== null) {
+      $sql .= " OFFSET {$this->offset}";
+    }
+    return $sql;
+  }
+  protected function buildWhereSql(): string
+  {
+    $sql = '';
+    foreach ($this->where as $index => $clause) {
+      $boolean = $index === 0 ? '' : $clause['boolean'] . ' ';
+      $sql .= $boolean . $clause['condition'] . ' ';
+    }
+    return trim($sql);
+  }
+
+  //Select부분분
   public function select(array|string $columns): static
   {
     $this->select = is_array($columns) ? $columns : explode(',', $columns);
     return $this;
   }
 
-  public function where(string $column, string $operator = "", mixed $value = ""): static
+  //Where절부분
+  public function where(array|string $column, mixed $operator = null, mixed $value = null): static
   {
+    if (is_array($column)) {
+      foreach ($column as $col => $val) {
+        $this->where($col, '=', $val);  // 재귀 호출
+      }
+      return $this;
+    }
+    // where("col = NOW()") 형태의 raw 처리
+    if ($operator === null && $value === null) {
+      $this->where[] = ['condition' => $column, 'boolean' => 'AND'];
+      return $this;
+    }
+    // where("col", "val") → operator 생략 시 = 처리
+    if ($value === null) {
+      $value = $operator;
+      $operator = '=';
+    }
     $placeholder = ':w_' . count($this->bindings);
-    $this->where[] = "$column $operator $placeholder";
+    $this->where[] = ['condition' => "$column $operator $placeholder", 'boolean' => 'AND'];
     $this->bindings[$placeholder] = $value;
     return $this;
   }
-
-  public function orderBy(string $column, string $direction = 'ASC'): static
+  public function orWhere(string $column, mixed $operator = null, mixed $value = null): static
   {
-    $this->order[] = "$column $direction";
-    return $this;
+    return $this->where($column, $operator, $value, "OR");
   }
 
-  public function limit(int $limit): static
-  {
-    $this->limit = $limit;
-    return $this;
-  }
-
-  public function offset(int $offset): static
-  {
-    $this->offset = $offset;
-    return $this;
-  }
-
-  public function when(bool $condition, callable $callback): static
-  {
-    if ($condition) {
-      $callback($this);
-    }
-    return $this;
-  }
-
-  public function rawWhere(string $expression, array $bindings = []): static
-  {
-    $this->where[] = "($expression)";
-    foreach ($bindings as $key => $value) {
-      $this->bindings[":raw_" . $key] = $value;
-    }
-    return $this;
-  }
-
-  public function get(): array
-  {
-    $sql = "SELECT " . implode(', ', $this->select) . " FROM {$this->table}";
-
-    if (!empty($this->where)) {
-      $sql .= " WHERE " . implode(' AND ', $this->where);
-    }
-
-    if (!empty($this->order)) {
-      $sql .= " ORDER BY " . implode(', ', $this->order);
-    }
-
-    if (!is_null($this->limit)) {
-      $sql .= " LIMIT :__limit";
-      $this->bindings[':__limit'] = $this->limit;
-    }
-
-    if (!is_null($this->offset)) {
-      $sql .= " OFFSET :__offset";
-      $this->bindings[':__offset'] = $this->offset;
-    }
-
-    $stmt = $this->pdo->prepare($sql);
-    foreach ($this->bindings as $placeholder => $value) {
-      $stmt->bindValue($placeholder, $value);
-    }
-
-    $stmt->execute();
-    return $stmt->fetchAll(PDO::FETCH_ASSOC);
-  }
-
-  public function first(): ?array
-  {
-    $this->limit(1);
-    $rows = $this->get();
-    return $rows[0] ?? null;
-  }
-
-  public function count(): int
-  {
-    $this->select = ['COUNT(*) AS cnt'];
-    $results = $this->get();
-    return (int)($results[0]['cnt'] ?? 0);
-  }
-
-  public function exists(): bool
-  {
-    return $this->count() > 0;
-  }
-
-  public function insert(array $data): bool
-  {
-    $columns = array_keys($data);
-    $placeholders = array_map(fn($col) => ':' . $col, $columns);
-
-    $sql = "INSERT INTO {$this->table} (" . implode(', ', $columns) . ") VALUES (" . implode(', ', $placeholders) . ")";
-    $stmt = $this->pdo->prepare($sql);
-
-    foreach ($data as $col => $value) {
-      $stmt->bindValue(':' . $col, $value);
-    }
-
-    return $stmt->execute();
-  }
-
-  public function update(array $data): bool
-  {
-    if (empty($this->where)) {
-      throw new \Exception("Update without WHERE is not allowed.");
-    }
-
-    $setClauses = [];
-    foreach ($data as $col => $val) {
-      $placeholder = ':u_' . $col;
-      $setClauses[] = "$col = $placeholder";
-      $this->bindings[$placeholder] = $val;
-    }
-
-    $sql = "UPDATE {$this->table} SET " . implode(', ', $setClauses);
-
-    if (!empty($this->where)) {
-      $sql .= " WHERE " . implode(' AND ', $this->where);
-    }
-
-    $stmt = $this->pdo->prepare($sql);
-    foreach ($this->bindings as $placeholder => $value) {
-      $stmt->bindValue($placeholder, $value);
-    }
-
-    return $stmt->execute();
-  }
-
-  public function delete(): bool
-  {
-    if (empty($this->where)) {
-      throw new \Exception("Delete without WHERE is not allowed.");
-    }
-
-    $sql = "DELETE FROM {$this->table} WHERE " . implode(' AND ', $this->where);
-    $stmt = $this->pdo->prepare($sql);
-    foreach ($this->bindings as $placeholder => $value) {
-      $stmt->bindValue($placeholder, $value);
-    }
-
-    return $stmt->execute();
-  }
-
-  public function whereIn(string $column, array $values, string $boolean = 'AND'): static
+  public function whereIn(string $column, array $values, string $boolean = 'AND', $conditon_boolean = "IN"): static
   {
     if (empty($values)) {
-      throw new \InvalidArgumentException("whereIn: values 배열이 비어있을 수 없습니다.");
+      throw new \InvalidArgumentException(__FUNCTION__ . ": values 배열이 비어있을 수 없습니다.");
     }
-
-    $placeholders = implode(', ', array_fill(0, count($values), '?'));
-    $this->where[] = "$column IN ($placeholders)";
-    $this->bindings = array_merge($this->bindings, $values);
-
+    $placeholders = [];
+    foreach ($values as $index => $value) {
+      $placeholder = ":in_" . count($this->bindings);
+      $placeholders[] = $placeholder;
+      $this->bindings[$placeholder] = $value;
+    }
+    $condition = "$column $conditon_boolean (" . implode(', ', $placeholders) . ")";
+    $this->where[] = ['condition' => $condition, 'boolean' => $boolean];
     return $this;
   }
-
-  public function whereNotIn(string $column, array $values, string $boolean = 'AND'): static
+  public function whereNotIn(string $column, array $values, $boolean = "AND", $conditon_boolean = "NOT IN"): static
   {
     if (empty($values)) {
-      throw new \InvalidArgumentException("whereNotIn: values 배열이 비어있을 수 없습니다.");
+      throw new \InvalidArgumentException(__FUNCTION__ . ": values 배열이 비어있을 수 없습니다.");
     }
-
-    $placeholders = implode(', ', array_fill(0, count($values), '?'));
-    $this->where[] = "$column NOT IN ($placeholders)";
-    $this->bindings = array_merge($this->bindings, $values);
-
-    return $this;
+    return $this->whereIn($column, $values, $boolean, $conditon_boolean);
   }
-
-  public function orWhereIn(string $column, array $values): static
+  public function orWhereIn(string $column, array $values, $boolean = "OR", $conditon_boolean = "IN"): static
   {
-    return $this->whereIn($column, $values, 'OR');
-  }
-
-  public function orWhere(string $column, string $operator, mixed $value): static
-  {
-    $placeholder = ':w_' . count($this->bindings);
-    $condition = "$column $operator $placeholder";
-
-    if (empty($this->where)) {
-      $this->where[] = $condition;
-    } else {
-      $last = array_pop($this->where);
-      $this->where[] = "($last OR $condition)";
+    if (empty($values)) {
+      throw new \InvalidArgumentException(__FUNCTION__ . ": values 배열이 비어있을 수 없습니다.");
     }
-
-    $this->bindings[$placeholder] = $value;
-    return $this;
+    return $this->whereIn($column, $values, $boolean, $conditon_boolean);
   }
 
+  //Join
   public function join(string $table, string $on, string $type = 'INNER'): static
   {
     $this->joins[] = strtoupper($type) . " JOIN $table ON $on";
     return $this;
   }
 
+  //Order
+  public function order(mixed $column, string $direction = 'ASC'): static
+  {
+    if (is_array($column)) {
+      // 배열 형식의 여러 컬럼 정렬을 처리
+      foreach ($column as $col => $dir) {
+        // 배열 키가 컬럼 이름이고 값이 방향임
+        $this->order[] = "$col $dir";
+      }
+    } else {
+      // 단일 컬럼에 대한 정렬
+      $this->order[] = "$column $direction";
+    }
+    return $this;
+  }
+  //Limit부분
+  public function limit(int $limit): static
+  {
+    $this->limit = $limit;
+    return $this;
+  }
+  public function offset(int $offset): static
+  {
+    $this->offset = $offset;
+    return $this;
+  }
+
+  //Customer SQL 실행부분
   public function raw(string $sql, array $bindings = []): array
   {
     $stmt = $this->pdo->prepare($sql);
@@ -246,6 +178,98 @@ class QueryBuilder
     return $stmt->fetchAll(PDO::FETCH_ASSOC);
   }
 
+  //Result부분
+  public function toRawSql(): string
+  {
+    $sql = $this->buildSelectSql();
+    $raw = $sql;
+    foreach ($this->bindings as $key => $value) {
+      $escaped = is_numeric($value) ? $value : $this->pdo->quote($value);
+      // 명명된 바인딩
+      if (str_starts_with($key, ':')) {
+        $raw = str_replace($key, $escaped, $raw);
+      } else {
+        // 물음표 바인딩인 경우 (whereIn 등)
+        $raw = preg_replace('/\?/', $escaped, $raw, 1);
+      }
+    }
+    return $raw;
+  }
+  public function get(): array
+  {
+    $sql = $this->buildSelectSql();
+    if ($this->_debug) {
+      echo "\nSQL DEBUG:" . $this->toRawSql();
+    }
+    $this->latestQuery = $this->toRawSql();
+    $stmt = $this->pdo->prepare($this->buildSelectSql());
+    foreach ($this->bindings as $key => $value) {
+      $stmt->bindValue($key, $value);
+    }
+    $stmt->execute();
+    $this->where = [];
+    $this->bindings = [];
+    return $stmt->fetchAll(PDO::FETCH_ASSOC);
+  }
+
+  public function first(): ?array
+  {
+    $this->limit = 1;
+    $results = $this->get();
+    return $results[0] ?? null;
+  }
+
+  public function count(): int
+  {
+    $this->select = ['COUNT(*) as cnt'];
+    $results = $this->get();
+    return (int)($results[0]['cnt'] ?? 0);
+  }
+
+  //CUD부분
+  public function insert(array $data): bool
+  {
+    $columns = array_keys($data);
+    $placeholders = array_map(fn($c) => ':' . $c, $columns);
+    $sql = "INSERT INTO {$this->table} (" . implode(',', $columns) . ") VALUES (" . implode(',', $placeholders) . ")";
+    $stmt = $this->pdo->prepare($sql);
+    foreach ($data as $col => $val) {
+      $stmt->bindValue(':' . $col, $val);
+    }
+    return $stmt->execute();
+  }
+
+  public function update(array $data): bool
+  {
+    if (empty($this->where)) throw new \Exception("Update without WHERE is not allowed.");
+
+    $setParts = [];
+    foreach ($data as $col => $val) {
+      $placeholder = ':u_' . $col;
+      $setParts[] = "$col = $placeholder";
+      $this->bindings[$placeholder] = $val;
+    }
+    $sql = "UPDATE {$this->table} SET " . implode(', ', $setParts)
+      . " WHERE " . implode(' AND ', $this->where);
+    $stmt = $this->pdo->prepare($sql);
+    foreach ($this->bindings as $k => $v) {
+      $stmt->bindValue($k, $v);
+    }
+    return $stmt->execute();
+  }
+
+  public function delete(): bool
+  {
+    if (empty($this->where)) throw new \Exception("Delete without WHERE is not allowed.");
+    $sql = "DELETE FROM {$this->table} WHERE " . implode(' AND ', $this->where);
+    $stmt = $this->pdo->prepare($sql);
+    foreach ($this->bindings as $k => $v) {
+      $stmt->bindValue($k, $v);
+    }
+    return $stmt->execute();
+  }
+
+  //transaction관련련
   public function beginTransaction(): void
   {
     $this->pdo->beginTransaction();
diff --git a/extdbms/lib/Services/ServiceService.php b/extdbms/lib/Services/ServiceService.php
index cd8b80e..f2abf22 100644
--- a/extdbms/lib/Services/ServiceService.php
+++ b/extdbms/lib/Services/ServiceService.php
@@ -4,7 +4,6 @@ namespace lib\Services;
 
 use lib\Entities\ServiceEntity as Entity;
 use lib\Models\ServiceModel as Model;
-use PDO;
 
 class ServiceService extends CommonService
 {
@@ -68,7 +67,7 @@ class ServiceService extends CommonService
     $this->getModel()->where($where);
     $this->getModel()->where(["service_line" => $type, "service_status" => 'o']);
     $this->getModel()->where("service_sw BETWEEN '{$switchcode_begin}' AND '$switchcode_end'");
-    $count =  $this->getModel()->countAllResults();
+    $count =  $this->getModel()->count();
     // echo "<BR>" . $this->getModel()->getLastQuery();
     return $count;
   }