feat(query-tool): 新增站點群組篩選功能

在批次追蹤工具中加入 WORKCENTER GROUP 篩選功能，讓使用者可以
選擇特定站點群組來過濾生產歷程，減少資料量提升查詢效能。

變更內容：
- 新增 /api/query-tool/workcenter-groups API 端點
- 修改 lot-history API 支援 workcenter_groups 參數
- 前端新增多選下拉選單篩選器 UI
- 後端 SQL 層級過濾，複用 filter_cache 機制
- 新增對應的單元測試和整合測試

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/mes_dashboard/routes/query_tool_routes.py

@@ -104,15 +104,24 @@ def query_lot_history():
 
     Query params:
         container_id: CONTAINERID (16-char hex)
+        workcenter_groups: Optional comma-separated list of WORKCENTER_GROUP names
 
     Returns production history records.
     """
     container_id = request.args.get('container_id')
+    workcenter_groups_param = request.args.get('workcenter_groups')
 
     if not container_id:
         return jsonify({'error': '請指定 CONTAINERID'}), 400
 
-    result = get_lot_history(container_id)
+    # Parse workcenter_groups if provided
+    workcenter_groups = None
+    if workcenter_groups_param:
+        workcenter_groups = [
+            g.strip() for g in workcenter_groups_param.split(',') if g.strip()
+        ]
+
+    result = get_lot_history(container_id, workcenter_groups=workcenter_groups)
 
     if 'error' in result:
         return jsonify(result), 400
@@ -317,6 +326,33 @@ def get_equipment_list():
         return jsonify({'error': f'載入設備資料失敗: {str(exc)}'}), 500
 
 
+# ============================================================
+# Workcenter Groups API (for filtering)
+# ============================================================
+
+@query_tool_bp.route('/api/query-tool/workcenter-groups', methods=['GET'])
+def get_workcenter_groups_list():
+    """Get available workcenter groups for filtering.
+
+    Returns workcenter groups list sorted by sequence.
+    Used for production history filtering UI.
+    """
+    from mes_dashboard.services.filter_cache import get_workcenter_groups
+
+    try:
+        groups = get_workcenter_groups()
+        if groups is None:
+            return jsonify({'error': '無法載入站點群組資料'}), 500
+
+        return jsonify({
+            'data': groups,
+            'total': len(groups)
+        })
+
+    except Exception as exc:
+        return jsonify({'error': f'載入站點群組失敗: {str(exc)}'}), 500
+
+
 # ============================================================
 # CSV Export API
 # ============================================================

src/mes_dashboard/services/query_tool_service.py

@@ -432,11 +432,28 @@ def _resolve_by_work_order(work_orders: List[str]) -> Dict[str, Any]:
 # LOT History Functions
 # ============================================================
 
-def get_lot_history(container_id: str) -> Dict[str, Any]:
+def _get_workcenters_for_groups(groups: List[str]) -> List[str]:
+    """Get workcenter names for given groups using filter_cache.
+
+    Args:
+        groups: List of WORKCENTER_GROUP names
+
+    Returns:
+        List of WORKCENTERNAME values
+    """
+    from mes_dashboard.services.filter_cache import get_workcenters_for_groups
+    return get_workcenters_for_groups(groups)
+
+
+def get_lot_history(
+    container_id: str,
+    workcenter_groups: Optional[List[str]] = None
+) -> Dict[str, Any]:
     """Get production history for a LOT.
 
     Args:
         container_id: CONTAINERID (16-char hex)
+        workcenter_groups: Optional list of WORKCENTER_GROUP names to filter by
 
     Returns:
         Dict with 'data' (history records) and 'total', or 'error'.
@@ -448,6 +465,20 @@ def get_lot_history(container_id: str) -> Dict[str, Any]:
         sql = SQLLoader.load("query_tool/lot_history")
         params = {'container_id': container_id}
 
+        # Add workcenter filter if groups specified
+        workcenter_filter = ""
+        if workcenter_groups:
+            workcenters = _get_workcenters_for_groups(workcenter_groups)
+            if workcenters:
+                workcenter_filter = f"AND {_build_in_filter(workcenters, 'h.WORKCENTERNAME')}"
+                logger.debug(
+                    f"Filtering by {len(workcenter_groups)} groups "
+                    f"({len(workcenters)} workcenters)"
+                )
+
+        # Replace placeholder in SQL
+        sql = sql.replace("{{ WORKCENTER_FILTER }}", workcenter_filter)
+
         df = read_sql_df(sql, params)
         data = _df_to_records(df)
 
@@ -457,6 +488,7 @@ def get_lot_history(container_id: str) -> Dict[str, Any]:
             'data': data,
             'total': len(data),
             'container_id': container_id,
+            'filtered_by_groups': workcenter_groups or [],
         }
 
     except Exception as exc:

src/mes_dashboard/sql/query_tool/lot_history.sql

@@ -3,6 +3,7 @@
 --
 -- Parameters:
 --   :container_id - CONTAINERID to query (16-char hex)
+--   {{ WORKCENTER_FILTER }} - Optional workcenter name filter (replaced by service)
 --
 -- Note: Uses EQUIPMENTID/EQUIPMENTNAME (NOT RESOURCEID/RESOURCENAME)
 --       Time fields: TRACKINTIMESTAMP/TRACKOUTTIMESTAMP (NOT TXNDATETIME)
@@ -33,6 +34,7 @@ WITH ranked_history AS (
     WHERE h.CONTAINERID = :container_id
       AND h.EQUIPMENTID IS NOT NULL
       AND h.TRACKINTIMESTAMP IS NOT NULL
+      {{ WORKCENTER_FILTER }}
 )
 SELECT
     CONTAINERID,

src/mes_dashboard/static/js/query-tool.js

@@ -20,6 +20,10 @@ const QueryToolState = {
     timelineSelectedLots: new Set(),  // Set of indices for timeline display
     currentLotIndex: 0,  // For association highlight
 
+    // Workcenter group filter
+    workcenterGroups: [],  // All available groups [{name, sequence}]
+    selectedWorkcenterGroups: new Set(),  // Selected group names for filtering
+
     // Equipment query
     allEquipments: [],
     selectedEquipments: new Set(),
@@ -46,6 +50,13 @@ function clearQueryState() {
     QueryToolState.timelineSelectedLots = new Set();
     QueryToolState.currentLotIndex = 0;
 
+    // Clear workcenter group selection (keep workcenterGroups as it's reused)
+    QueryToolState.selectedWorkcenterGroups = new Set();
+
+    // Hide workcenter group selector
+    const wcContainer = document.getElementById('workcenterGroupSelectorContainer');
+    if (wcContainer) wcContainer.style.display = 'none';
+
     // Clear equipment query state
     QueryToolState.equipmentResults = null;
     // Note: Keep allEquipments and selectedEquipments as they are reused
@@ -99,6 +110,7 @@ window.clearQueryState = clearQueryState;
 
 document.addEventListener('DOMContentLoaded', () => {
     loadEquipments();
+    loadWorkcenterGroups();  // Load workcenter groups for filtering
     setLast30Days();
 
     // Close dropdowns when clicking outside
@@ -116,6 +128,13 @@ document.addEventListener('DOMContentLoaded', () => {
         if (lotSelector && !lotSelector.contains(e.target)) {
             lotDropdown.classList.remove('show');
         }
+
+        // Workcenter group dropdown
+        const wcDropdown = document.getElementById('wcGroupDropdown');
+        const wcSelector = document.getElementById('workcenterGroupSelectorContainer');
+        if (wcSelector && !wcSelector.contains(e.target)) {
+            if (wcDropdown) wcDropdown.classList.remove('show');
+        }
     });
 
     // Handle Enter key in search input
@@ -259,9 +278,15 @@ async function executeLotQuery() {
         // Initialize with empty selection - user must confirm
         QueryToolState.timelineSelectedLots = new Set();
 
+        // Clear workcenter group selection for new query
+        QueryToolState.selectedWorkcenterGroups = new Set();
+
         // Hide LOT info bar initially
         document.getElementById('lotInfoBar').style.display = 'none';
 
+        // Show workcenter group selector for filtering
+        showWorkcenterGroupSelector();
+
         if (resolveResult.data.length === 1) {
             // Single result - auto-select and show directly
             QueryToolState.timelineSelectedLots.add(0);
@@ -372,8 +397,14 @@ async function confirmLotSelection() {
         return;
     }
 
-    // Close dropdown
+    // Close dropdowns
     document.getElementById('lotSelectorDropdown').classList.remove('show');
+    const wcDropdown = document.getElementById('wcGroupDropdown');
+    if (wcDropdown) wcDropdown.classList.remove('show');
+
+    // Build workcenter_groups parameter
+    const wcGroups = Array.from(QueryToolState.selectedWorkcenterGroups);
+    const wcGroupsParam = wcGroups.length > 0 ? wcGroups.join(',') : null;
 
     // Update display
     const count = selectedIndices.length;
@@ -383,24 +414,29 @@ async function confirmLotSelection() {
     document.getElementById('lotInfoBar').style.display = 'none';
 
     const panel = document.getElementById('lotResultsContent');
+    const filterInfo = wcGroupsParam ? ` (篩選: ${wcGroups.length} 個站點群組)` : '';
     panel.innerHTML = `
         <div class="loading">
             <div class="loading-spinner"></div>
-            <br>載入所選批次資料...
+            <br>載入所選批次資料...${filterInfo}
         </div>
     `;
 
-    // Load history for all selected lots
+    // Clear cached histories when filter changes
+    QueryToolState.lotHistories = {};
+
+    // Load history for all selected lots WITH workcenter filter
     try {
         await Promise.all(selectedIndices.map(async (idx) => {
             const lot = QueryToolState.resolvedLots[idx];
-            if (!QueryToolState.lotHistories[lot.container_id]) {
-                const result = await MesApi.get('/api/query-tool/lot-history', {
-                    params: { container_id: lot.container_id }
-                });
-                if (!result.error) {
-                    QueryToolState.lotHistories[lot.container_id] = result.data || [];
-                }
+            const params = { container_id: lot.container_id };
+            if (wcGroupsParam) {
+                params.workcenter_groups = wcGroupsParam;
+            }
+
+            const result = await MesApi.get('/api/query-tool/lot-history', { params });
+            if (!result.error) {
+                QueryToolState.lotHistories[lot.container_id] = result.data || [];
             }
         }));
 
@@ -2146,6 +2182,170 @@ async function showAdjacentLots(equipmentId, specName, targetTime) {
     }
 }
 
+// ============================================================
+// Workcenter Group Filter Functions
+// ============================================================
+
+async function loadWorkcenterGroups() {
+    try {
+        const result = await MesApi.get('/api/query-tool/workcenter-groups', {
+            silent: true
+        });
+        if (result.error) {
+            console.error('Failed to load workcenter groups:', result.error);
+            return;
+        }
+
+        QueryToolState.workcenterGroups = result.data || [];
+        console.log(`[QueryTool] Loaded ${QueryToolState.workcenterGroups.length} workcenter groups`);
+    } catch (error) {
+        console.error('Error loading workcenter groups:', error);
+    }
+}
+
+function renderWorkcenterGroupSelector() {
+    const container = document.getElementById('workcenterGroupSelector');
+    if (!container) return;
+
+    const groups = QueryToolState.workcenterGroups;
+    const selected = QueryToolState.selectedWorkcenterGroups;
+    const count = selected.size;
+
+    let html = `
+        <div class="wc-group-selector">
+            <button type="button" class="wc-group-btn" onclick="toggleWorkcenterGroupDropdown()">
+                <span id="wcGroupDisplay">${count === 0 ? '全部站點' : `${count} 個站點群組`}</span>
+                <span class="wc-group-badge" id="wcGroupBadge" style="display: ${count > 0 ? 'inline-block' : 'none'};">${count}</span>
+                <svg width="12" height="12" viewBox="0 0 12 12" fill="none" style="margin-left: auto;">
+                    <path d="M3 4.5L6 7.5L9 4.5" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/>
+                </svg>
+            </button>
+            <div class="wc-group-dropdown" id="wcGroupDropdown">
+                <div class="wc-group-header">
+                    <label style="cursor: pointer; display: flex; align-items: center; gap: 6px;">
+                        <input type="checkbox" id="wcGroupSelectAll" onchange="toggleAllWorkcenterGroups(this.checked)"
+                               ${selected.size === groups.length && groups.length > 0 ? 'checked' : ''}>
+                        全選
+                    </label>
+                    <span id="wcGroupSelectedCount">已選 ${count}</span>
+                </div>
+                <div class="wc-group-search">
+                    <input type="text" placeholder="搜尋站點群組..." oninput="filterWorkcenterGroups(this.value)">
+                </div>
+                <div class="wc-group-list" id="wcGroupList">
+    `;
+
+    groups.forEach(group => {
+        const isSelected = selected.has(group.name);
+        html += `
+            <div class="wc-group-item ${isSelected ? 'selected' : ''}" data-group="${group.name}">
+                <label onclick="event.stopPropagation();">
+                    <input type="checkbox" ${isSelected ? 'checked' : ''}
+                           onchange="toggleWorkcenterGroup('${group.name}', this.checked)">
+                    ${group.name}
+                </label>
+            </div>
+        `;
+    });
+
+    html += `
+                </div>
+                <div class="wc-group-footer">
+                    <button type="button" class="btn btn-sm btn-secondary" onclick="clearWorkcenterGroups()">清除</button>
+                    <button type="button" class="btn btn-sm btn-primary" onclick="closeWorkcenterGroupDropdown()">確定</button>
+                </div>
+            </div>
+        </div>
+    `;
+
+    container.innerHTML = html;
+}
+
+function toggleWorkcenterGroup(groupName, checked) {
+    if (checked) {
+        QueryToolState.selectedWorkcenterGroups.add(groupName);
+    } else {
+        QueryToolState.selectedWorkcenterGroups.delete(groupName);
+    }
+    updateWorkcenterGroupUI();
+}
+
+function toggleAllWorkcenterGroups(checked) {
+    if (checked) {
+        QueryToolState.workcenterGroups.forEach(g => {
+            QueryToolState.selectedWorkcenterGroups.add(g.name);
+        });
+    } else {
+        QueryToolState.selectedWorkcenterGroups.clear();
+    }
+    renderWorkcenterGroupSelector();
+}
+
+function clearWorkcenterGroups() {
+    QueryToolState.selectedWorkcenterGroups.clear();
+    renderWorkcenterGroupSelector();
+}
+
+function updateWorkcenterGroupUI() {
+    const count = QueryToolState.selectedWorkcenterGroups.size;
+    const display = document.getElementById('wcGroupDisplay');
+    const badge = document.getElementById('wcGroupBadge');
+    const countEl = document.getElementById('wcGroupSelectedCount');
+    const selectAll = document.getElementById('wcGroupSelectAll');
+
+    // Update item visual state
+    document.querySelectorAll('.wc-group-item').forEach(item => {
+        const groupName = item.dataset.group;
+        const isSelected = QueryToolState.selectedWorkcenterGroups.has(groupName);
+        item.classList.toggle('selected', isSelected);
+        const checkbox = item.querySelector('input[type="checkbox"]');
+        if (checkbox) checkbox.checked = isSelected;
+    });
+
+    // Update display text and badge
+    if (display) {
+        display.textContent = count === 0 ? '全部站點' : `${count} 個站點群組`;
+    }
+    if (badge) {
+        badge.textContent = count;
+        badge.style.display = count > 0 ? 'inline-block' : 'none';
+    }
+    if (countEl) {
+        countEl.textContent = `已選 ${count}`;
+    }
+    if (selectAll) {
+        selectAll.checked = count === QueryToolState.workcenterGroups.length && count > 0;
+    }
+}
+
+function toggleWorkcenterGroupDropdown() {
+    const dropdown = document.getElementById('wcGroupDropdown');
+    if (dropdown) dropdown.classList.toggle('show');
+}
+
+function closeWorkcenterGroupDropdown() {
+    const dropdown = document.getElementById('wcGroupDropdown');
+    if (dropdown) dropdown.classList.remove('show');
+}
+
+function filterWorkcenterGroups(searchText) {
+    const items = document.querySelectorAll('.wc-group-item');
+    const search = searchText.toLowerCase();
+
+    items.forEach(item => {
+        const groupName = item.dataset.group.toLowerCase();
+        item.style.display = groupName.includes(search) ? 'flex' : 'none';
+    });
+}
+
+function showWorkcenterGroupSelector() {
+    const container = document.getElementById('workcenterGroupSelectorContainer');
+    if (container && QueryToolState.workcenterGroups.length > 0) {
+        container.style.display = 'block';
+        renderWorkcenterGroupSelector();
+    }
+}
+
 // ============================================================
 // Equipment Query Functions
 // ============================================================

src/mes_dashboard/templates/query_tool.html

@@ -196,6 +196,136 @@
             z-index: 1;
         }
 
+        /* Workcenter Group Selector */
+        .wc-group-selector {
+            position: relative;
+        }
+
+        .wc-group-btn {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            padding: 8px 12px;
+            border: 1px solid #ddd;
+            border-radius: 6px;
+            background: white;
+            cursor: pointer;
+            font-size: 14px;
+            min-width: 160px;
+            transition: border-color 0.2s;
+        }
+
+        .wc-group-btn:hover {
+            border-color: #4e54c8;
+        }
+
+        .wc-group-badge {
+            background: #4e54c8;
+            color: white;
+            padding: 2px 8px;
+            border-radius: 10px;
+            font-size: 12px;
+            font-weight: 600;
+        }
+
+        .wc-group-dropdown {
+            position: absolute;
+            top: 100%;
+            left: 0;
+            min-width: 280px;
+            max-height: 400px;
+            background: white;
+            border: 1px solid #ddd;
+            border-radius: 6px;
+            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
+            z-index: 1000;
+            display: none;
+            margin-top: 4px;
+        }
+
+        .wc-group-dropdown.show {
+            display: block;
+        }
+
+        .wc-group-header {
+            padding: 10px 12px;
+            border-bottom: 1px solid #e0e0e0;
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+            font-size: 13px;
+            background: #fafafa;
+        }
+
+        .wc-group-search {
+            padding: 8px 12px;
+            border-bottom: 1px solid #f0f0f0;
+        }
+
+        .wc-group-search input {
+            width: 100%;
+            padding: 6px 10px;
+            border: 1px solid #ddd;
+            border-radius: 4px;
+            font-size: 13px;
+        }
+
+        .wc-group-search input:focus {
+            outline: none;
+            border-color: #4e54c8;
+        }
+
+        .wc-group-list {
+            max-height: 280px;
+            overflow-y: auto;
+        }
+
+        .wc-group-item {
+            display: flex;
+            align-items: center;
+            padding: 8px 12px;
+            cursor: pointer;
+            font-size: 13px;
+            border-bottom: 1px solid #f5f5f5;
+            transition: background 0.15s;
+        }
+
+        .wc-group-item:hover {
+            background: #f5f7ff;
+        }
+
+        .wc-group-item.selected {
+            background: #e8f4e8;
+        }
+
+        .wc-group-item label {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            cursor: pointer;
+            width: 100%;
+        }
+
+        .wc-group-item input[type="checkbox"] {
+            width: 16px;
+            height: 16px;
+            accent-color: #4e54c8;
+        }
+
+        .wc-group-footer {
+            padding: 10px 12px;
+            border-top: 1px solid #e0e0e0;
+            display: flex;
+            justify-content: flex-end;
+            gap: 8px;
+            background: #fafafa;
+        }
+
+        .wc-group-footer .btn-sm {
+            padding: 6px 12px;
+            font-size: 12px;
+        }
+
         /* LOT info bar */
         .lot-info-bar {
             display: flex;
@@ -991,6 +1121,14 @@
                         <!-- LOT options will be populated here -->
                     </div>
                 </div>
+
+                <!-- Workcenter Group Filter (appears after query) -->
+                <div class="filter-item" id="workcenterGroupSelectorContainer" style="display: none;">
+                    <label>站點篩選</label>
+                    <div id="workcenterGroupSelector">
+                        <!-- Rendered by JS -->
+                    </div>
+                </div>
             </div>
 
             <!-- Equipment Query Filter Bar (hidden by default) -->

tests/test_query_tool_routes.py

@@ -536,3 +536,105 @@ class TestEquipmentListEndpoint:
         assert response.status_code == 500
         data = json.loads(response.data)
         assert 'error' in data
+
+
+class TestWorkcenterGroupsEndpoint:
+    """Tests for /api/query-tool/workcenter-groups endpoint."""
+
+    @patch('mes_dashboard.services.filter_cache.get_workcenter_groups')
+    def test_returns_groups_list(self, mock_get_groups, client):
+        """Should return workcenter groups list."""
+        mock_get_groups.return_value = [
+            {'name': 'DB', 'sequence': 1},
+            {'name': 'WB', 'sequence': 2},
+        ]
+
+        response = client.get('/api/query-tool/workcenter-groups')
+
+        assert response.status_code == 200
+        data = json.loads(response.data)
+        assert 'data' in data
+        assert len(data['data']) == 2
+        assert data['total'] == 2
+
+    @patch('mes_dashboard.services.filter_cache.get_workcenter_groups')
+    def test_handles_cache_failure(self, mock_get_groups, client):
+        """Should return 500 when cache fails."""
+        mock_get_groups.return_value = None
+
+        response = client.get('/api/query-tool/workcenter-groups')
+
+        assert response.status_code == 500
+        data = json.loads(response.data)
+        assert 'error' in data
+
+    @patch('mes_dashboard.services.filter_cache.get_workcenter_groups')
+    def test_handles_exception(self, mock_get_groups, client):
+        """Should handle exception gracefully."""
+        mock_get_groups.side_effect = Exception('Cache error')
+
+        response = client.get('/api/query-tool/workcenter-groups')
+
+        assert response.status_code == 500
+        data = json.loads(response.data)
+        assert 'error' in data
+
+
+class TestLotHistoryWithWorkcenterFilter:
+    """Tests for /api/query-tool/lot-history with workcenter filter."""
+
+    @patch('mes_dashboard.routes.query_tool_routes.get_lot_history')
+    def test_accepts_workcenter_groups_param(self, mock_query, client):
+        """Should pass workcenter_groups parameter to service."""
+        mock_query.return_value = {
+            'data': [],
+            'total': 0,
+            'filtered_by_groups': ['DB', 'WB']
+        }
+
+        response = client.get(
+            '/api/query-tool/lot-history?'
+            'container_id=abc123&workcenter_groups=DB,WB'
+        )
+
+        assert response.status_code == 200
+        # Verify the service was called with workcenter_groups
+        call_args = mock_query.call_args
+        assert call_args[1].get('workcenter_groups') == ['DB', 'WB']
+
+    @patch('mes_dashboard.routes.query_tool_routes.get_lot_history')
+    def test_empty_workcenter_groups_ignored(self, mock_query, client):
+        """Should ignore empty workcenter_groups parameter."""
+        mock_query.return_value = {
+            'data': [],
+            'total': 0,
+            'filtered_by_groups': []
+        }
+
+        response = client.get(
+            '/api/query-tool/lot-history?'
+            'container_id=abc123&workcenter_groups='
+        )
+
+        assert response.status_code == 200
+        # Verify workcenter_groups is None (not empty list)
+        call_args = mock_query.call_args
+        assert call_args[1].get('workcenter_groups') is None
+
+    @patch('mes_dashboard.routes.query_tool_routes.get_lot_history')
+    def test_returns_filtered_by_groups_in_response(self, mock_query, client):
+        """Should include filtered_by_groups in response."""
+        mock_query.return_value = {
+            'data': [{'CONTAINERID': 'abc123'}],
+            'total': 1,
+            'filtered_by_groups': ['DB']
+        }
+
+        response = client.get(
+            '/api/query-tool/lot-history?'
+            'container_id=abc123&workcenter_groups=DB'
+        )
+
+        assert response.status_code == 200
+        data = json.loads(response.data)
+        assert data.get('filtered_by_groups') == ['DB']

tests/test_query_tool_service.py

@@ -292,3 +292,129 @@ class TestServiceConstants:
     def test_max_equipments_is_reasonable(self):
         """Max equipments should be sensible."""
         assert 5 <= MAX_EQUIPMENTS <= 50
+
+
+class TestGetWorkcenterForGroups:
+    """Tests for _get_workcenters_for_groups helper function."""
+
+    def test_calls_filter_cache(self):
+        """Should call filter_cache.get_workcenters_for_groups."""
+        from unittest.mock import patch
+
+        with patch('mes_dashboard.services.filter_cache.get_workcenters_for_groups') as mock_get:
+            from mes_dashboard.services.query_tool_service import _get_workcenters_for_groups
+            mock_get.return_value = ['DB_1', 'DB_2']
+
+            result = _get_workcenters_for_groups(['DB'])
+
+            mock_get.assert_called_once_with(['DB'])
+            assert result == ['DB_1', 'DB_2']
+
+    def test_returns_empty_list_for_unknown_group(self):
+        """Should return empty list for unknown group."""
+        from unittest.mock import patch
+
+        with patch('mes_dashboard.services.filter_cache.get_workcenters_for_groups') as mock_get:
+            from mes_dashboard.services.query_tool_service import _get_workcenters_for_groups
+            mock_get.return_value = []
+
+            result = _get_workcenters_for_groups(['UNKNOWN'])
+
+            assert result == []
+
+
+class TestGetLotHistoryWithWorkcenterFilter:
+    """Tests for get_lot_history with workcenter_groups filter."""
+
+    def test_no_filter_returns_all(self):
+        """When no workcenter_groups, should not add filter to SQL."""
+        from unittest.mock import patch, MagicMock
+        import pandas as pd
+
+        with patch('mes_dashboard.services.query_tool_service.read_sql_df') as mock_read:
+            with patch('mes_dashboard.services.query_tool_service.SQLLoader') as mock_loader:
+                from mes_dashboard.services.query_tool_service import get_lot_history
+
+                mock_loader.load.return_value = 'SELECT * FROM t WHERE c = :container_id {{ WORKCENTER_FILTER }}'
+                mock_read.return_value = pd.DataFrame({
+                    'CONTAINERID': ['abc123'],
+                    'WORKCENTERNAME': ['DB_1'],
+                })
+
+                result = get_lot_history('abc123', workcenter_groups=None)
+
+                assert 'error' not in result
+                assert result['filtered_by_groups'] == []
+                # Verify SQL does not contain WORKCENTERNAME IN
+                sql_called = mock_read.call_args[0][0]
+                assert 'WORKCENTERNAME IN' not in sql_called
+                assert '{{ WORKCENTER_FILTER }}' not in sql_called
+
+    def test_with_filter_adds_condition(self):
+        """When workcenter_groups provided, should filter by workcenters."""
+        from unittest.mock import patch
+        import pandas as pd
+
+        with patch('mes_dashboard.services.query_tool_service.read_sql_df') as mock_read:
+            with patch('mes_dashboard.services.query_tool_service.SQLLoader') as mock_loader:
+                with patch('mes_dashboard.services.filter_cache.get_workcenters_for_groups') as mock_get_wc:
+                    from mes_dashboard.services.query_tool_service import get_lot_history
+
+                    mock_loader.load.return_value = 'SELECT * FROM t WHERE c = :container_id {{ WORKCENTER_FILTER }}'
+                    mock_get_wc.return_value = ['DB_1', 'DB_2']
+                    mock_read.return_value = pd.DataFrame({
+                        'CONTAINERID': ['abc123'],
+                        'WORKCENTERNAME': ['DB_1'],
+                    })
+
+                    result = get_lot_history('abc123', workcenter_groups=['DB'])
+
+                    mock_get_wc.assert_called_once_with(['DB'])
+                    assert result['filtered_by_groups'] == ['DB']
+                    # Verify SQL contains filter
+                    sql_called = mock_read.call_args[0][0]
+                    assert 'WORKCENTERNAME' in sql_called
+
+    def test_empty_groups_list_no_filter(self):
+        """Empty groups list should return all (no filter)."""
+        from unittest.mock import patch
+        import pandas as pd
+
+        with patch('mes_dashboard.services.query_tool_service.read_sql_df') as mock_read:
+            with patch('mes_dashboard.services.query_tool_service.SQLLoader') as mock_loader:
+                from mes_dashboard.services.query_tool_service import get_lot_history
+
+                mock_loader.load.return_value = 'SELECT * FROM t WHERE c = :container_id {{ WORKCENTER_FILTER }}'
+                mock_read.return_value = pd.DataFrame({
+                    'CONTAINERID': ['abc123'],
+                    'WORKCENTERNAME': ['DB_1'],
+                })
+
+                result = get_lot_history('abc123', workcenter_groups=[])
+
+                assert result['filtered_by_groups'] == []
+                # Verify SQL does not contain WORKCENTERNAME IN
+                sql_called = mock_read.call_args[0][0]
+                assert 'WORKCENTERNAME IN' not in sql_called
+
+    def test_filter_with_empty_workcenters_result(self):
+        """When group has no workcenters, should not add filter."""
+        from unittest.mock import patch
+        import pandas as pd
+
+        with patch('mes_dashboard.services.query_tool_service.read_sql_df') as mock_read:
+            with patch('mes_dashboard.services.query_tool_service.SQLLoader') as mock_loader:
+                with patch('mes_dashboard.services.filter_cache.get_workcenters_for_groups') as mock_get_wc:
+                    from mes_dashboard.services.query_tool_service import get_lot_history
+
+                    mock_loader.load.return_value = 'SELECT * FROM t WHERE c = :container_id {{ WORKCENTER_FILTER }}'
+                    mock_get_wc.return_value = []  # No workcenters for this group
+                    mock_read.return_value = pd.DataFrame({
+                        'CONTAINERID': ['abc123'],
+                        'WORKCENTERNAME': ['DB_1'],
+                    })
+
+                    result = get_lot_history('abc123', workcenter_groups=['UNKNOWN'])
+
+                    # Should still succeed, just no filter applied
+                    assert 'error' not in result