sql select查询动态添加列,标识列

时间:2019-10-29
本文章向大家介绍sql select查询动态添加列,标识列，主要包括sql select查询动态添加列,标识列使用实例、应用技巧、基本知识点总结和需要注意事项，具有一定的参考价值，需要的朋友可以参考一下。

1. 使用单引号, 默认值(标识列)

  select 
      'good' as "ELable",
    "DGHashId" as "EHashId",
    "DHashId" as "DHashId",
    "PHashId" as "PHashId",
    "DSNames" as "EContent",    
    "DGDiagnosisTime" as "EDateTime",
    "DGStatus" as "EStatus",
    "DGUpdateTime" as "ECreateTime"
    from "Diagnosis" where
        "DHashId" ='4444444444444444'
        and "PHashId" = 'c61b362b1c9dcd09'
        and "DGStatus" = 1

效果图如下:

 1. 使用ROW_NUMBER() ;(优点,主要用排序功能)

 select 
      row_number() over(order by "DHashId") as "ELable",
    "DGHashId" as "EHashId",
    "DHashId" as "DHashId",
    "PHashId" as "PHashId",
    "DSNames" as "EContent",    
    "DGDiagnosisTime" as "EDateTime",
    "DGStatus" as "EStatus",
    "DGUpdateTime" as "ECreateTime"
    from "Diagnosis" where
        "DHashId" ='4444444444444444'
        and "PHashId" = 'c61b362b1c9dcd09'
        and "DGStatus" = 1

效果如下图:

原文地址：https://www.cnblogs.com/han-guang-xue/p/11759450.html

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