perf: reduce worker order list query load

apps/backend/src/repositories/worker-platform-repo.test.ts

@@ -110,6 +110,12 @@ test('后台接单工单支持按接单分类筛选', () => {
   assert.deepEqual(query.params, [7])
 })
 
+test('空白搜索词不生成全表 LIKE 条件', () => {
+  const query = buildWorkOrderWhere({ keyword: '   ' })
+  assert.doesNotMatch(query.whereClause, /LIKE LOWER/)
+  assert.deepEqual(query.params, [])
+})
+
 test('大厅候选按分类上限取队首后再受全局上限限制', () => {
   const query = buildWorkOrderWhere({
     hallCandidateLimit: 20,

apps/backend/src/repositories/worker-platform/work-order-query-repo.ts

@@ -58,6 +58,13 @@ export const WORK_ORDER_SELECT = `
   ) share_summary ON TRUE
 `
 
+// Keep the page and total in one filtered query. This avoids running the same
+// joins and share aggregation twice for every list request.
+const LIST_WORK_ORDER_SELECT = WORK_ORDER_SELECT.replace(
+  '  SELECT\n',
+  '  SELECT\n    COUNT(*) OVER()::int AS total_count,\n',
+)
+
 type WorkerOrderOverviewRow = {
   status: string
   order_count: number
@@ -268,15 +275,6 @@ export async function listWorkOrders({
     createdFrom,
     createdTo,
   })
-  const totalResult = await query<{ total: number }>(
-    `
-      SELECT COUNT(*)::int AS total
-      FROM work_orders wo
-      ${joins}
-      ${whereClause}
-    `,
-    params,
-  )
   const offset = (page - 1) * pageSize
   const orderBy =
     sort === 'worker_claimed_at_desc' && workerSharingId
@@ -292,14 +290,30 @@ export async function listWorkOrders({
   const effectiveOrderBy = pinnedFirst ? `wo.pinned_at DESC NULLS LAST, ${orderBy}` : orderBy
   params.push(pageSize, offset)
   const itemsResult = await query<WorkOrderRow>(
-    `${WORK_ORDER_SELECT}
+    `${LIST_WORK_ORDER_SELECT}
      ${joins}
      ${whereClause}
      ORDER BY ${effectiveOrderBy}
      LIMIT $${params.length - 1} OFFSET $${params.length}`,
     params,
   )
-  return { items: itemsResult.rows, total: Number(totalResult.rows[0]?.total || 0) }
+  // A page beyond the end has no row from which to read the window count.
+  // Keep that uncommon pagination edge case correct without restoring a
+  // second query for normal requests.
+  let total = Number(
+    (itemsResult.rows[0] as WorkOrderRow & { total_count?: number })?.total_count || 0,
+  )
+  if (itemsResult.rows.length === 0 && page > 1) {
+    const totalResult = await query<{ total: number }>(
+      `SELECT COUNT(*)::int AS total FROM work_orders wo ${joins} ${whereClause}`,
+      params.slice(0, -2),
+    )
+    total = Number(totalResult.rows[0]?.total || 0)
+  }
+  return {
+    items: itemsResult.rows,
+    total,
+  }
 }
 
 /** 按筛选条件汇总工单，统计范围不受当前分页影响。 */