使用多个 if 条件简化程序

Posted 2023-03-28

【中文标题】使用多个 if 条件简化程序

【英文标题】：Simplify procedure with multiple if condition

【发布时间】：2021-04-22 16:50:06

【问题描述】：

我是新手，有一个需要简化的程序。 它有多个 if 和 inserts，我想简化它。

BEGIN

IF oldProductType IS NOT NULL AND PRODUCTTYPE != oldProductType THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Product Type', oldProductType, PRODUCTTYPE, '');

UPDATE ab_project SET product_type = PRODUCTTYPE where project_id = PROJECTID;

END IF;

IF oldProgramManager IS NOT NULL AND PROGRAMMANAGER != oldProgramManager THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Program Manager', oldProgramManager, PROGRAMMANAGER, '');

          UPDATE ab_project SET program_manager = PROGRAMMANAGER where project_id = PROJECTID;

END IF;

IF oldProductManager IS NOT NULL AND PRODUCTMANAGER != oldProductManager THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Product Manager', oldProductManager, PRODUCTMANAGER, '');

          UPDATE ab_project SET product_manager = PRODUCTMANAGER where project_id = PROJECTID;

END IF;

IF oldProductName IS NOT NULL AND PRODUCTNAME != oldProductName THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Product Name', oldProductName, PRODUCTNAME, '');

            UPDATE ab_project SET product_name = PRODUCTNAME where project_id = PROJECTID;

END IF;

IF oldDescription IS NOT NULL AND PRODUCTDESCRIPTION != oldDescription THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Product Description', oldDescription, PRODUCTDESCRIPTION, '');

            UPDATE ab_project SET product_description = PRODUCTDESCRIPTION where project_id = PROJECTID;

END IF;

IF oldRequestType IS NOT NULL AND REQUESTTYPE != oldRequestType THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Request Type', oldRequestType, REQUESTTYPE, '');

           UPDATE ab_project SET request_type = REQUESTTYPE where project_id = PROJECTID;

END IF;

IF oldOtherProduct IS NOT NULL AND OTHERPRODUCT != oldOtherProduct THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Other Product', oldOtherProduct, OTHERPRODUCT, '');

          UPDATE ab_project SET Other_Product = OTHERPRODUCT where project_id = PROJECTID;

END IF;

IF oldBusinessRationale IS NOT NULL AND BUSINEs-s-rATIONALE != oldBusinessRationale THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Business Rationale', oldBusinessRationale, BUSINEs-s-rATIONALE, '');

            UPDATE ab_project SET business_rationale = BUSINEs-s-rATIONALE where project_id = PROJECTID;

END IF;

IF oldSoftwareDependency IS NOT NULL AND SOFTWAREDEPENDENCY != oldSoftwareDependency THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Software Dependency', oldSoftwareDependency, SOFTWAREDEPENDENCY, '');

           UPDATE ab_project SET software_dependency = SOFTWAREDEPENDENCY where project_id = PROJECTID;

END IF;

IF OldOtherDependency IS NOT NULL AND OTHERDEPENDENCY != OldOtherDependency THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Other Dependency', OldOtherDependency, OTHERDEPENDENCY, '');

              UPDATE ab_project SET other_dependency = OTHERDEPENDENCY where project_id = PROJECTID;

END IF;

IF OldReleaseCycleID IS NOT NULL AND RELEASECYCLEID != OldReleaseCycleID THEN

groupIdVal := prcChangeGroupIdSeq.NEXTVAL;

INSERT INTO CHANGE_GROUP VALUES(groupIdVal,projectid,user_id,SYSDATE);

 insert into change_log (id, groupId, type, field, oldvalue, newvalue, fieldtypeid) 
          values (prcChangeLogIdSeq.NEXTVAL, groupIdVal, 'project', 'Release Cycle ID', OldReleaseCycleID, RELEASECYCLEID, '');

             UPDATE ab_project SET release_cycle_id = RELEASECYCLEID where project_id = PROJECTID;

END IF;


commit;
exception
when others then
    raise_application_error(-20001,'An error was encountered - '||SQLCODE||' - Error - '||SQLERRM);
end;

【问题讨论】：

这里的“优化”是什么意思？通常，这指的是性能，这意味着您在这里遇到性能问题。如果是这种情况，您对代码进行了哪些分析？各种语句的查询计划是什么？如果没有表和索引定义，看起来一切都在进行单行插入和更新操作，这应该很快。假设多个 if 语句可以同时为真，您可以将单独的 ab_project 更新替换为单个更新，但这不应该是一个巨大的改进。

但也许你没有使用正常意义上的“优化”，你真的在​​问是否可以简化/重构过程？

是的，也许我没有使用正确的词。因为，我是新手，我想知道是否有更好的方法来编写这段代码

好的。那你能解释一下这个程序在做什么，为什么？例如，每个if 语句都对change_group 执行相同的插入操作。因此，如果 6 个 if 语句全部为真，那么您将在 change_group 中获得 6 个新行，除了序列生成的主键之外的相同数据。这似乎不太可能有用。我认为您需要一个 update 或 ab_project，而不是在每个 if 语句中都有一个 update，除非有某种原因您真的希望同一行可能被更新多次。

您的异常处理程序似乎没有做任何有用的事情，只是隐藏了有关实际发生错误的错误堆栈的信息。我会完全摆脱它，除非你能在你提出的异常中真正增加价值。

【参考方案1】：

CASE 可能就是你想要的