diff --git a/app/controllers/shixuns_controller.rb b/app/controllers/shixuns_controller.rb
index 56fe8fc35..20ff348a6 100644
--- a/app/controllers/shixuns_controller.rb
+++ b/app/controllers/shixuns_controller.rb
@@ -45,10 +45,11 @@ class ShixunsController < ApplicationController
 		if params[:keyword].present?
 			keyword = params[:keyword].strip
 			@shixuns = @shixuns.joins(:user, challenges: :challenge_tags).
-					where("challenge_tags.name like '%#{keyword}%'
-                  or challenges.subject like '%#{keyword}%'
-                  or concat(lastname, firstname) like '%#{keyword}%'
-                  or shixuns.name like '%#{keyword.split(" ").join("%")}%'").distinct
+					where("challenge_tags.name like :keyword
+                  or challenges.subject like :keyword
+                  or concat(lastname, firstname) like :keyword
+                  or shixuns.name like :name",
+								keyword: "%#{keyword}%", name: "%#{keyword.split(" ").join("%")}%").distinct
 		end
 
 		## 筛选 状态
@@ -66,17 +67,17 @@ class ShixunsController < ApplicationController
 		bsort = params[:sort] || 'desc'
 		case params[:order_by] || 'publish_time'
 			when 'new'
-				@shixuns = @shixuns.order("shixuns.status = 2 desc, shixuns.created_at #{bsort}")
+				@shixuns = @shixuns.reorder("shixuns.status = 2 desc, shixuns.created_at #{bsort}")
 			when 'hot'
-				@shixuns = @shixuns.order("shixuns.status = 2 desc, myshixuns_count #{bsort}")
+				@shixuns = @shixuns.reorder("shixuns.status = 2 desc, shixuns.myshixuns_count #{bsort}")
       when 'mine'
-        @shixuns = @shixuns.order("shixuns.created_at #{bsort}")
+        @shixuns = @shixuns.reorder("shixuns.created_at #{bsort}")
       else
-				@shixuns = @shixuns.order("shixuns.status = 2 desc, publish_time #{bsort}")
+				@shixuns = @shixuns.reorder("shixuns.status = 2 desc, shixuns.publish_time #{bsort}")
 		end
 
-
-		@total_count = @shixuns.count
+		# 用id计数会快10MS左右。
+		@total_count = @shixuns.count("shixuns.id")
 
 		## 分页参数
 		page  = params[:page]  || 1