Oracle：比较两个不同表中没有主键的字符串列以查找匹配/不匹配的字符串

Question

我有两个表，我们想比较这些表中的两个字符串列。这些表中没有与 where 子句匹配的主键。表格如下： 比较应该忽略：

1. 忽略字符串中任何位置的空格 2) 忽略区分大小写

输出需求：

Answer 1

您可以在连接条件中将full outer join 与upper 和replace 函数一起使用，如下所示：

Select t1.str, t2.str,
       Case when t1.str is not null and t2.str is not null then 'exist in both table'
             when t1.str is not null then 'missing in table2'
             Else 'missing in table1'
       End as differences
From table1 t1 full join table2 t2
  On upper(replace(t1.str,' ','') = upper(replace(t2.str,' ','')

Answer 2

同样地；第 1 - 16 行的样本数据。您可能需要的查询从第 17 行开始。

SQL> with
  2  tab1 (col) as
  3    (select 'mg/kl'     from dual union all
  4     select 'k/mg'      from dual union all
  5     select 'l/g/kg'    from dual union all
  6     select 'umol_Ulp'  from dual union all
  7     select '10*12_/KG' from dual union all
  8     select 'a/L/G'     from dual
  9    ),
 10  tab2 (col) as
 11    (select '10*12_/kg' from dual union all
 12     select '1/L/G'     from dual union all
 13     select 'PG/7@R'    from dual union all
 14     select 'KG/CM/L'   from dual union all
 15     select 'l/g/kg'    from dual
 16    )
 17  select a.col, b.col,
 18    case when lower(a.col) = lower(b.col) then
 19              'exists in both tables ' ||
 20              case when a.col = b.col then 'and exact match'
 21                   else 'but different'
 22              end
 23         when a.col is null then 'missing in table 1'
 24         when b.col is null then 'missing in table 2'
 25    end differences
 26  from tab1 a full outer join tab2 b on lower(a.col) = lower(b.col);

COL       COL       DIFFERENCES
--------- --------- -------------------------------------
mg/kl               missing in table 2
k/mg                missing in table 2
l/g/kg    l/g/kg    exists in both tables and exact match
umol_Ulp            missing in table 2
10*12_/KG 10*12_/kg exists in both tables but different
a/L/G               missing in table 2
          KG/CM/L   missing in table 1
          PG/7@R    missing in table 1
          1/L/G     missing in table 1

9 rows selected.

SQL>

Answer 3

尝试以下 SQL 一次，看看是否有效。否则，您能否分享那些它说“在表 2 中缺失”的值，即使它在两个表中都存在？

Select t1.str, t2.str,
       Case when nvl(t1.str,'X') != 'X' and nvl(t2.str,'X') != 'X' then 'exist in both table'
             when nvl(t1.str,'X') != 'X' then 'missing in table2'
             Else 'missing in table1'
       End as differences
From table1 t1 full join table2 t2
  On upper(trim(t1.str)) = upper(trim(t2.str))