Using rownum greater than or equal to or less than or equal to the result of paging is incorrect in Oracle

[dreapur]

在Oracle下使用Shardingjdbc的分页时遇到一个问题，比如我的SQL是：SELECT * FROM (SELECT A1., ROWNUM RN1 FROM (SELECT * FROM t_order ORDER BY user_id DESC) A1 WHERE ROWNUM <= 10) B WHERE B.RN1 >= 1，正常情况下应该返回10条数据，但是Shardingjdbc返回了9条数据，漏掉了本来的第一条数据。我看了一下在每个分片的执行语句：SELECT * FROM (SELECT A1., ROWNUM RN1 FROM (SELECT * FROM t_order_0 ORDER BY user_id DESC) A1 WHERE ROWNUM <= 10) B WHERE B.RN1 >= 0，这里RowNum变成从0开始的，是Shardingjdbc默认RowNum从0开始吗，这里Shardingjdbc的处理逻辑是怎样的呢，还是说这里存在Bug？

[terrymanu]

sql改写会改为0，但归并时会按1归并。这个不是bug。
关于为什么取的数据不对，到有可能是bug。请提供可重现的代码以便我们定位

[dreapur]

@terrymanu 使用的是官网提供的"sharding-jdbc-raw-jdbc-java-example"这个工程，作了简单的修改：
1.DataSourceUtils改成连接Oracle数据库
2.t_order表使用标准分片策略，算法就是例子提供的算法，PreciseShardingAlgorithm泛型改为Integer，“order_id”作分片字段
String shardingColumn = "order_id"; String algorithmClassNameForModulo = "io.shardingjdbc.example.jdbc.java.algorithm.ModuloShardingTableAlgorithm"; StandardShardingStrategyConfiguration sSSC = new StandardShardingStrategyConfiguration(shardingColumn, algorithmClassNameForModulo); orderTableRuleConfig.setTableShardingStrategyConfig(sSSC);
3.建表语句和插入语句
CREATE TABLE t_order (order_id NUMBER(2) NOT NULL, user_id NUMBER(2) NOT NULL, status VARCHAR2(50))
for (int i = 1; i < 40; i++) { String sql = "INSERT INTO t_order (order_id, user_id,status) VALUES (" + i + ", " + (i + 1) + ",'INIT')"; execute(dataSource,sql); }
4.查询语句
SELECT * FROM (SELECT A1.*, ROWNUM RN1 FROM (SELECT * FROM t_order ORDER BY user_id DESC) A1 WHERE ROWNUM <= 10) B WHERE B.RN1 >= 1
预期结果有10条数据，实际结果只有9条，缺少了"order_id:39,user_id:40"这条记录
order_id:38, user_id:39,
order_id:37, user_id:38,
order_id:36, user_id:37,
order_id:35, user_id:36,
order_id:34, user_id:35,
order_id:33, user_id:34,
order_id:32, user_id:33,
order_id:31, user_id:32,
order_id:30, user_id:31,

[terrymanu]

fixed at 2.0.1