SQL 错误:ROW_NUMBER() OVER (PARTITION) [英] SQL error: ROW_NUMBER() OVER (PARTITION

问题描述

我的 SQL 代码有什么问题?

What is wrong with my SQL code?

我尝试在此答案

但我不断收到以下错误:

But I keep getting the following error:

("附近:语法错误:SELECT rn = ROW_NUMBER() OVER (

near "(": syntax error: SELECT rn = ROW_NUMBER() OVER (

这里是SQL代码:

SELECT 
    rn = ROW_NUMBER() OVER (PARTITION BY s.stop_id, s.stop_name 
                            ORDER BY s.stop_id, s.stop_name)
FROM stops s

我在某处读到它与 SQL 版本或 sqlite3 的使用有关 ??

I read somewhere that it has to do with SQL versions or the usage of sqlite3 ??

这里有一些关于这个问题的额外信息:

Here some additional information to the problem:

我有起始表:

table_beginning =
[some_text0 , some_text1 , some_text2 ,  some_text3   ]
[ bla_1     ,   monday   ,    red     , bla_something ]
[ bla_77    ,   tuesday  ,   green    , bla_other     ]
[ bla_99    ,   monday   ,    blue    , bla_anything  ]
[ bla_00    ,  wednesday ,    red     , bla_maybe     ]
[ bla_55    ,   monday   ,   violet   , bla_more      ]
[ bal_66    ,   monday   ,    red     , bla_kind      ]
[ bal_22    ,   monday   ,    red     , bla_stuff     ]

我想最终得到一个关于 col_2 和 col_3 没有重复的表(不关心 col_1 和 col_4 是什么！！)

I would like to end up with a table that has no doublicates concerning col_2 and col_3 (not caring whatever col_1 and col_4 are !!)

例如:

table_final1 =
[some_text0 , some_text1 , some_text2 ,  some_text3   ]
[ bla_1     ,   monday   ,    red     , bla_something ]
[ bla_77    ,   tuesday  ,   green    , bla_other     ]
[ bla_99    ,   monday   ,    blue    , bla_anything  ]
[ bla_00    ,  wednesday ,    red     , bla_maybe     ]
[ bla_55    ,   monday   ,   violet   , bla_more      ]

(--> 哪些行被踢出并不重要.因此，接受的最终表也可能如下所示:

(--> which ones of the rows that are kicked out does not matter. The accepted final table could therefore also look like:

table_final2 =
[some_text0 , some_text1 , some_text2 ,  some_text3   ]
[ bla_77    ,   tuesday  ,   green    , bla_other     ]
[ bla_99    ,   monday   ,    blue    , bla_anything  ]
[ bla_00    ,  wednesday ,    red     , bla_maybe     ]
[ bla_55    ,   monday   ,   violet   , bla_more      ]
[ bal_66    ,   monday   ,    red     , bla_kind      ]

或

table_final3 =
[some_text0 , some_text1 , some_text2 ,  some_text3   ]
[ bla_77    ,   tuesday  ,   green    , bla_other     ]
[ bla_99    ,   monday   ,    blue    , bla_anything  ]
[ bla_00    ,  wednesday ,    red     , bla_maybe     ]
[ bla_55    ,   monday   ,   violet   , bla_more      ]
[ bal_22    ,   monday   ,    red     , bla_stuff     ]

重要的是 col_2 和 col_3 从来没有相同的两个条目！

All that matters is that col_2 and col_3 have never the same two entries !

如你所见 some_text1 = monday AND some_text2 = red 现在只存在一次！！(从col_2和col_3的角度排除重复)

As you can see some_text1 = monday AND some_text2 = red exists now only once !! (eliminating doublicates from the point of view only looking at col_2 and col_3)

至于 col_1 和 col_4 中的内容 - 我根本不在乎里面有什么！我只关心 col_2 和 col_3 里面有什么(那里没有任何重复！)

As of content in col_1 and col_4 - I don't care at all what is in there ! I'm only concerned about what is inside col_2 and col_3 (not having any doublicates there !)

一种解决方案:

我想出了一种方法(但也许有更优雅的方法??)

I figured out a way (but maybe there is a more elegant one??)

CREATE TABLE table_intermediate AS
  SELECT DISTINCT col_2, col_3
FROM table_beginning;

--> 这将创建一个中间表--> 使用 DISTINCT 关键字这确实消除了重复-->(缺点，我完全丢失了 col_1 和 col_4 信息)

--> This creates an intermediate table --> with the DISTINCT keyword this does eliminate doublicates --> (disadvantage, I loose col_1 and col_4 information completely)

也许有一个解决方案可以让我保留有关 col_1 和 col_4 的信息???(同样，我不在乎 col_1 或 col_4 中的哪一个！)

Maybe there is a solution where I can keep information on col_1 and col_4 ??? (again, which of the col_1 or col_4 I do not care !)

推荐答案

在 SQLite 中，通常可以使用 rowid:

In SQLite, you can typically use rowid:

select s.*
from stops s
where s.rowid = (select min(s2.rowid)
                 from stops s2
                 where s2.stop_id = s.stop_id and s2.stop_name = s.stop_name
                );

我不确定这是否是您真正需要的.但这似乎是您想要用 row_number() 做的事情.如果这没有达到目的，请使用示例数据和所需结果提出另一个问题.

I'm not sure if this is what you really need. But this seems to be what you want to do with row_number(). If this doesn't hit the spot, then ask another question with sample data and desired results.

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