Question

表A拉回表B中的行。如果表B的col2是＆＃39; XYZ＆＃39;那么我只想要包含XYZ的行用于该id。

Table A   Table B
id bid    bid  col2  
1  2      2    ABC
1  3      3    ABC
2  4      4    ABC
2  5      5    XYZ

输出总共有3行，id为1行，id为2行。

这是我到目前为止所尝试的

select * from table a, table b
where a.col1 = b.col1
and if 'ABC' in (select b1.col2 from table b1 where b1.col1 = b.col1)  then b.col2 = 'ABC' end
and if 'XYZ' in (select b1.col2 from table b1 where b1.col1 = b.col1)  then b.col2 = 'XYZ' end

我也试过

and case when (select count(b1.col) from table b1 where b1.col = b.col1 and b1.col = 'XYZ') >0 then b.col1 = 'XYZ' end

确切代码

select *
from scores a, queues b 
where res_id = '112321'
and b.que_id = a.que_id
and case when (select count(qasgn_cd) from queues where que_id = b.que_id and QASGN_CD = 'BTQFR') >0 then b.que_id = '1' else FALSE end

给出错误ORA-00905：缺少关键字

Answer 1

使用CASE子句中的WHERE语句尝试以下内容：

select *
from scores a, queues b 
where res_id = '112321'
and b.que_id = a.que_id
and case when (select count(qasgn_cd)
               from queues 
               where que_id = b.que_id 
               and QASGN_CD = 'BTQFR') > 0 
    then TRUE
    else FALSE
    end

Answer 2

假设您的表格如下：

create table "Table A" (   
   id  number, 
   bid number
);

insert into "Table A" values (1,  2);
insert into "Table A" values (1,  3);
insert into "Table A" values (2,  4);    
insert into "Table A" values (2,  5);    


create table "Table B" (   
   bid  number, 
   col2 varchar2(50)
);

insert into "Table B" values (2,    'ABC');
insert into "Table B" values (3,    'ABC');
insert into "Table B" values (4,    'ABC');
insert into "Table B" values (5,    'XYZ');

您可以按ID对数据进行分区，并区分包含“XYZ”的分区和不包含“XYZ”的分区。在外部选择中，您只需过滤结果。

select * 
  from (select a.*,
               b.col2,
               count(case when b.COL2 = 'XYZ' then 1 else null end) over (partition by a.ID) as cnt
          from "Table A" a
          join "Table B" b on b.BID = a.BID) t
 where (t.cnt = 0)
    or (t.cnt = 1 and t.col2 = 'XYZ');

你也可以在where子句中使用“case when ......”，但在这种情况下它不是必需的。

select * 
  from (select a.*,
               b.col2,
               count(case when b.COL2 = 'XYZ' then 1 else null end) over (partition by a.ID) as cnt
          from "Table A" a
          join "Table B" b on b.BID = a.BID) t
 where case 
          when (t.cnt = 0) 
            or (t.cnt = 1 and t.col2 = 'XYZ') then 1 
          else NULL 
       end = 1;

如何在oracle sql中创建条件where子句

2 个答案: