使用 hsql db 时查询得到 "invalid order by" 而 Mysql 没有（结果只能是一列）

Question

虽然此查询在 MySQL 数据库中运行正常：

SELECT DISTINCT user_id  
FROM table_name 
WHERE user_name IN (:userNameList) 
  AND user_type IN ('client','vip')   
ORDER BY user_login_time DESC
LIMIT 10  OFFSET 0

当我尝试通过 HSQL 运行相同的查询时，出现此错误：

nested exception is java.sql.SQLSyntaxErrorException: invalid ORDER BY expression in statement [SELECT DISTINCT user_id FROM table_name WHERE user_name IN (:userNameList) AND user_type IN ('client','vip') ORDER BY user_login_time desc LIMIT 10 OFFSET 0]

Answer 1

这个问题的解决方案需要我更改查询：在 HSQL 中我们必须 select 按列排序。没有它，我们会收到此错误。

SELECT DISTINCT user_id, user_login_time  
FROM table_name 
WHERE user_name IN (:userNameList) 
  AND user_type IN ('client','vip')   
ORDER BY user_login_time DESC
LIMIT 10  OFFSET 0

但是这个解决方案 return 是两列而不是一列。

通过使用 JDBCTAmplate，我找到了一种方法 return 只有一列

String query = "SELECT DISTINCT user_id , user_login_time  FROM table_name WHERE user_name IN (:userNameList) AND user_type IN ('client','vip') ORDER BY user_login_time DESC LIMIT 10  OFFSET 0";
    
List<String> userIds = new ArrayList<String>();
List<String> userIdList = List.of("12345667", "123443235");
Map<String, Object> sqlParameterSource = new HashMap<>();
sqlParameterSource.put("userNameList", userIdList);
                
userIds = namedParamJDBCTemplate.query(query, new MapSqlParameterSource(sqlParameterSource), new ResultSetExtractor<List>() {
                 
                    @Override
                    public List extractData(ResultSet resultSet) throws SQLException, DataAccessException {
                        List<String> listRes = new ArrayList<String>();
                        while (resultSet.next()) {
                            listRes.add(resultSet.getString(USER_ID));
                        }
                        return listRes;
                    }
                });

这个解决方案允许我通过 HSQL 运行查询，结果仍然只得到一列。

Answer 2

像这样的查询 returns 只有 user_id 列

SELECT user_id FROM 
  ( SELECT DISTINCT user_id, user_login_time  
    FROM table_name 
    WHERE user_name IN (:userNameList) 
    AND user_type IN ('client','vip')   
    ORDER BY user_login_time DESC
    LIMIT 10  OFFSET 0 )

如果一个用户多次登录，MySQL查询returns一行用户，其中一次登录时间用于下单，可能不是该用户最后一次登录时间.

最好使用GROUP BY来确保结果一致：

SELECT user_id 
FROM table_name 
WHERE user_name IN (:userNameList) 
  AND user_type IN ('client','vip')   
GROUP BY user_id
ORDER BY MAX(user_login_time) DESC
LIMIT 10  OFFSET 0

使用 hsql db 时查询得到 "invalid order by" 而 Mysql 没有（结果只能是一列）

Query gets "invalid order by" when using hsql db while Mysql does not ( result must be one column only)

mysql

sql

hsqldb

jdbctemplate