带有 WITH 子句的 SQL 值太多错误

【问题标题】：SQL with WITH clause too many values error带有 WITH 子句的 SQL 值太多错误
【发布时间】：2016-10-22 09:22:40
【问题描述】：

--此查询返回“值过多”错误。我不确定为什么？

   update myTable
            set var1= var2
            WHERE value1 IN (

             WITH X AS
            (
            select value1, value2, var1,var2, ROW_NUMBER()
            OVER
            (PARTITION BY value1 ORDER BY value1 desc) as rn
            from
              mytable WHERE var1 is null AND rownum>0 and rownum<=10 order by value1 asc
            )
            SELECT
            value1, value2, var2,var1
           FROM X WHERE rn=1  and var1 is null and rownum>0 and rownum<=10);

【问题讨论】：

标签： sql oracle11g sqlplus with-statement

【解决方案1】：

错误too many values 是因为查询具有value1 IN ()，其中在内部查询中选择了多个列。为避免这种情况，只需在内部查询中使用select value1。

update myTable
set var1 = var2
WHERE value1 IN
     (select value1 from 
       (select value1, value2, var1,var2, 
        ROW_NUMBER() OVER (PARTITION BY value1 ORDER BY value1 desc) as rn
        from mytable 
        WHERE var1 is null
        ) t 
      where rn <= 10
      )

【讨论】：

【解决方案2】：

我认为使用exists 可以更好地满足您的意图：

update myTable
    set var1 = var2
    where exists (select 1
                  from (select value1, value2, var1, var2, 
                               ROW_NUMBER() OVER (PARTITION BY value1 ORDER BY value1 desc) as rn
                       from mytable 
                       where var1 is null
                      ) x
                  where mytable.value1 in (x.value1, x.value2, x.var1, x.var2) and
                        rn <= 10
                 );

【讨论】：