diff --git a/src/com/hellogithub/dao/projectDao.java b/src/com/hellogithub/dao/projectDao.java
index 4a74a59..376e097 100644
--- a/src/com/hellogithub/dao/projectDao.java
+++ b/src/com/hellogithub/dao/projectDao.java
@@ -24,7 +24,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where periodicals = ? ORDER BY categoryId";
+            String sql = "select * from project where periodicals = ? and isValid = 1ORDER BY categoryId";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class), num);
             conn.close();
         } catch (SQLException e) {
@@ -42,7 +42,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project Order BY periodicals DESC limit 1";
+            String sql = "select * from project where isValid = 1 Order BY periodicals DESC limit 1";
             projectEntity = runner.query(conn, sql, new BeanHandler<>(projectEntity.class));
             conn.close();
         } catch (SQLException e) {
@@ -61,7 +61,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select count(*) as num from project";
+            String sql = "select count(*) as num from project where isValid = 1";
             p  = runner.query(conn, sql, new BeanHandler<>(projectEntity.class));
             count = p.getNum();
             conn.close();
@@ -81,7 +81,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where categoryId = ?";
+            String sql = "select * from project where categoryId = ? and isValid = 1";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class), num);
             conn.close();
         } catch (SQLException e) {
@@ -94,7 +94,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project;";
+            String sql = "select * from project where isValid = 1 ";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class));
             conn.close();
         } catch (SQLException e) {
@@ -107,7 +107,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where projectId in (select projectId from project_category where categoryId in(select categoryId from category where categoryName = ?))";
+            String sql = "select * from project where  isValid = 1 and projectId in (select projectId from project_category where categoryId in(select categoryId from category where categoryName = ?)) ";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class),name);
             conn.close();
         } catch (SQLException e) {
@@ -121,7 +121,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where projectId in (select projectId from project_category where categoryId in(select categoryId from category where categoryName = ?)) order by lookCount desc";
+            String sql = "select * from project where isValid = 1 and projectId in (select projectId from project_category where categoryId in(select categoryId from category where categoryName = ?)) order by lookCount desc";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class),name);
             conn.close();
         } catch (SQLException e) {
@@ -134,7 +134,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project order by lookCount desc";
+            String sql = "select * from project where isValid = 1 order by lookCount desc";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class));
             conn.close();
         } catch (SQLException e) {
@@ -148,7 +148,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "SELECT * FROM project WHERE projectName LIKE %?%";
+            String sql = "SELECT * FROM project WHERE isValid = 1 and projectName LIKE %?%";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class), str);
             conn.close();
         } catch (SQLException e) {
@@ -180,7 +180,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where projectId = ?";
+            String sql = "select * from project where isValid = 1 and projectId = ?";
             projectEntity = runner.query(conn, sql, new BeanHandler<>(projectEntity.class),id);
             conn.close();
         } catch (SQLException e) {
@@ -197,7 +197,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "UPDATE project SET lookcount = lookcount+1 WHERE projectId= ?";
+            String sql = "UPDATE project SET lookcount = lookcount+1 WHERE isValid = 1 and projectId= ? ";
             num = runner.update(conn, sql,id);
             conn.close();
         } catch (SQLException e) {
@@ -229,7 +229,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project Order By ProjectId DESC limit 1";
+            String sql = "select * from project where isValid = 1 Order By ProjectId DESC limit 1";
             projectEntity = runner.query(conn, sql,new BeanHandler<>(projectEntity.class));
             num = projectEntity.getProjectId();
             conn.close();
diff --git a/src/com/hellogithub/service/projectService.java b/src/com/hellogithub/service/projectService.java
index 60cb444..b5e204e 100644
--- a/src/com/hellogithub/service/projectService.java
+++ b/src/com/hellogithub/service/projectService.java
@@ -158,12 +158,13 @@ public class projectService {
     }
 
     public List<projectEntity> randomSelect(){
-        List<projectEntity> projectEntityList = null;
+        List<projectEntity> projectEntityList = new ArrayList<>();
         long t = System.currentTimeMillis();
         Random random = new Random(t);
+        List<projectEntity> projectEntityList1 = projectDao.retLatestProject();
         for(int i=0;i<5;i++)
         {
-            projectEntity projectEntity = projectDao.selectProById(String.valueOf(random.nextInt(projectDao.retMaxProId())));
+            projectEntity projectEntity =projectEntityList1.get(random.nextInt(projectEntityList1.size()));
             projectEntityList.add(projectEntity);
         }
         return projectEntityList;