JPA 获取某个表的所有字段名、判断某个表中某个字段是否存在、返回表中存在的字段名

缺乏、安全感 2022-11-07 13:16 0阅读 0赞

### 1 获取某个表的所有字段名 ###

/**
         * 获取某个表的所有字段名
         *
         * @return
         * @throws SQLException
         */
        public List<String> getAllColumnNames(String tableName) {
            List<String> list = new ArrayList<String>();
            SessionFactory sessionFactory = entityManagerFactory.unwrap(SessionFactory.class);
            Session session = sessionFactory.openSession();
            if (session != null) {
                list = session.doReturningWork(
                        connection -> {
                            List<String> resultList = new ArrayList<>();
                            ResultSet rs;
                            String username=connection.getMetaData().getUserName();
                            try {
                                rs = connection.getMetaData().getColumns(connection.getCatalog(), username, tableName, null);
                                while (rs.next()) {
                                    String column= rs.getObject(4).toString();
                                    resultList.add(column);
                                }
                            } catch (SQLException e) {
                                //不存在
                                return resultList;
                            }
                            rs.close();
                            return resultList;
                        }
                );
                session.close();
            }
            return list;
        }

### 2 判断某个表中某个字段是否存在 ###

/**
         * 判断某个表中某个字段是否存在
         *
         * @return
         */
        public boolean checkColumnNameExist(String tableName,String columnName) {
            List<String> columnNameList=getAllColumnNames();
            if(columnNameList==null||columnNameList.size()<=0){
                return false;
            }
            return columnNameList.contains(columnName)?true:false;
        }

### 3 返回表中存在的字段名 ###

/**
         * 返回表中存在的字段名
         *
         * @return
         */
        public List<String> getExistColumnNameList(List<String> columnNameList) {
            List<String> allColumnNameList=getAllColumnNames();
            if(allColumnNameList==null||allColumnNameList.size()<=0){
                return new ArrayList<>();
            }
            return allColumnNameList.stream().filter(x->columnNameList.contains(x)).collect(Collectors.toList());
        }