如何在单个插入语句中执行多个插入到..select 查询？

Question

我有多个 insert into..select 语句，如下所示。如果您看到，在所有三个语句中只有一个列值（Req_Attrname）在变化。其他一切都相同，包括where 条件。

插入语句 1)

insert into details(repo_phyid,repo_type,repo_attrname,repo_Attrvalue
                    ,Req_phyid,Req_type,Req_Attrname,Req_attrvalue) 
select demo.phyid,'Complementary Item','Product Management Responsible',demo.attr_value,
                   tnr.phyid,'Complementary Item','**Product Manager**',demo.attr_value
       From repo_Tnr Tnr,repo_Tnr_Attribute demo 
       Where Tnr.Phyid=demo.Phyid 
             And demo.Attr_Name='Product Management Responsible'
             and tnr.type='Complementary Item'

插入语句 2)

insert into details(repo_phyid,repo_type,repo_attrname,repo_Attrvalue,
                     Req_phyid,Req_type,Req_Attrname,Req_attrvalue) 
select demo.phyid,'Complementary Item','Product Management Responsible',demo.attr_value,
                   tnr.phyid,'Complementary Item','**Quality Manager**',demo.attr_value
       From repo_Tnr Tnr,repo_Tnr_Attribute demo 
       Where Tnr.Phyid=demo.Phyid 
             And demo.Attr_Name='Product Management Responsible'
             and tnr.type='Complementary Item'

插入语句 3)

insert into details(repo_phyid,repo_type,repo_attrname,repo_Attrvalue
                    ,Req_phyid,Req_type,Req_Attrname,Req_attrvalue) 
select demo.phyid,'Complementary Item','Product Management Responsible',demo.attr_value
                    ,tnr.phyid,'Complementary Item',**'Depty Engineer**',demo.attr_value
        From repo_Tnr Tnr,repo_Tnr_Attribute demo 
        Where Tnr.Phyid=demo.Phyid 
              And demo.Attr_Name='Product Management Responsible'
              and tnr.type='Complementary Item'

我在这里尝试的是，如果选择返回我 20 行，首先我必须插入 20 行 Product Manager 作为 Req_attrname 的值，然后我必须插入相同的 20 行但 Quality Manager 并再次与Deputy Engineer 。为此，我使用了 3 个插入语句。像这样我有 15 到 20 个插入语句。有没有办法可以在单个插入语句中做到这一点？它将帮助我减少代码并增加可读性。请提供替代解决方案。

Answer 1

由于Req_Attrname 都是常量，您可以在原始查询中从dual 和cross join 查询所有这些结果，这样您就可以从查询中获得与每个Req_Attrname 匹配的每一行：

INSERT INTO details (repo_phyid,
                     repo_type,
                     repo_attrname,
                     repo_attrvalue,
                     req_phyid,
                     req_type,
                     req_attrname,
                     req_attrvalue) 
SELECT     demo.phyid,
           'Complementary Item',
           'Product Management Responsible',
           demo.attr_value,
           tnr.phyid,
           'Complementary Item',
           req_attrname,
           demo.attr_value
FROM       repo_tnr tnr
JOIN       repo_tnr_tttribute demo ON tnr.phyid = demo.phyid
CROSS JOIN (SELECT '**Product Manager**' AS req_attrname FROM dual
            UNION ALL
            SELECT '**Quality Manager**' AS req_attrname FROM dual
            UNION ALL
            SELECT '**Depty Engineer**'  AS req_attrname FROM dual) t
WHERE      demo.attr_name = 'Product Management Responsible' AND
           tnr.type = 'Complementary Item'