René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"cross join不能成功转换","articleBody":"当cross join关联多个表的时候，不能成功转换。\r\ntest case:\r\nSelect * from table_c as v  cross join table_b, table_c\r\n转换后：\r\nSelect * from table_c as v  cross join table_b, table_c\r\n\r\n\r\n查看源码发现：\r\n````\r\nprivate boolean hasJoin( TJoinList joins )\r\n\t{\r\n\t\tif ( joins == null )\r\n\t\t\treturn false;\r\n\t\tfor ( int i = 0; i \u003c joins.size( ); i++ )\r\n\t\t{\r\n\t\t\tif ( joins.getJoin( i ).getJoinItems( ) != null\r\n\t\t\t\t\t\u0026\u0026 joins.getJoin( i ).getJoinItems( ).size( ) \u003e 0 )\r\n\t\t\t\treturn true;\r\n\t\t}\r\n\t\treturn false;\r\n\t}\r\n````\r\n当cross join关联表的时候， joins.getJoin( i ).getJoinItems( )不为null，并且size大于0直接返回了true，导致没有进入cross join的转换方法中，但是cross join的getJoinItems( )实际上应该为null，因为joins.getJoin(i).getJoinItems().getJoinItem(j).toString()为null，cross join的hasJoin校验应该为false，缺少这一步判断，所以会导致直接不能转换，修改源码为：\r\n````\r\nprivate boolean hasJoin(TJoinList joins) {\r\n        if (joins == null)\r\n            return false;\r\n        for (int i = 0; i \u003c joins.size(); i++) {\r\n            TJoinItemList joinItems = joins.getJoin(i).getJoinItems();\r\n            if (null != joinItems \u0026\u0026 joinItems.size() \u003e 0) {\r\n                for (int j = 0; j \u003c joinItems.size(); j++) {\r\n                    if (null == joinItems.getJoinItem(j).toString()) {\r\n                        return false;\r\n                    }\r\n                }\r\n                return true;\r\n            }\r\n        }\r\n        return false;\r\n    }\r\n````\r\n即可。","author":{"url":"https://github.com/CembZy","@type":"Person","name":"CembZy"},"datePublished":"2020-06-29T07:17:45.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/7/gsp_demo_java/issues/7"}