堆栈内存溢出
  简体   繁体   English

SQL 循环遍历具有名称的列以查找最大日期

[英]SQL loop through columns with name to find max date

 原文  2020-07-16 07:55:42  3   1    sql/ oracle

问题描述

I'm looking for the SQL to loop through 20 columns with dates, to find the max.我正在寻找 SQL 循环遍历 20 列的日期，以找到最大值。

My code is kind of bad now:我的代码现在有点糟糕：

,case 
    when ANNEX_20_DATE is not null and ANNEX_20_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_20_DATE
    when ANNEX_19_DATE is not null and ANNEX_19_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_19_DATE
    when ANNEX_18_DATE is not null and ANNEX_18_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_18_DATE
    when ANNEX_17_DATE is not null and ANNEX_17_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_17_DATE
    when ANNEX_16_DATE is not null and ANNEX_16_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_16_DATE
    when ANNEX_15_DATE is not null and ANNEX_15_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_15_DATE
    when ANNEX_14_DATE is not null and ANNEX_14_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_14_DATE
    when ANNEX_13_DATE is not null and ANNEX_13_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_13_DATE
    when ANNEX_12_DATE is not null and ANNEX_12_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_12_DATE
    when ANNEX_11_DATE is not null and ANNEX_11_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_11_DATE
    when ANNEX_10_DATE is not null and ANNEX_10_DATE<>to_date ('19000101', 'yyyy-mm-dd')            then ANNEX_10_DATE
    when ANNEX_9_DATE is not null and ANNEX_9_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_9_DATE
    when ANNEX_8_DATE is not null and ANNEX_8_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_8_DATE
    when ANNEX_7_DATE is not null and ANNEX_7_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_7_DATE
    when ANNEX_6_DATE is not null and ANNEX_6_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_6_DATE
    when ANNEX_5_DATE is not null and ANNEX_5_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_5_DATE
    when ANNEX_4_DATE is not null and ANNEX_4_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_4_DATE
    when ANNEX_3_DATE is not null and ANNEX_3_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_3_DATE
    when ANNEX_2_DATE is not null and ANNEX_2_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_2_DATE
    when ANNEX_1_DATE is not null and ANNEX_1_DATE<>to_date ('19000101', 'yyyy-mm-dd')              then ANNEX_1_DATE
    
    ELSE 'N/A'

it's oracle database, i konow that max date is in filed annex_20它是 oracle 数据库，我知道最大日期在附件 20 中

1 个解决方案

解决方案1
 2 已采纳  2020-07-16 12:34:51

First of all, you don't need ANNEX_XX_DATE is not null since ANNEX_XX_DATE<>... can't be true if ANNEX_XX_DATE is null, so you can make it easier without it:首先，你不需要ANNEX_XX_DATE is not null因为ANNEX_XX_DATE<>...如果 ANNEX_XX_DATE 是 null 就不可能是真的，所以没有它你可以让它更容易：

,case 
    when ANNEX_20_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_20_DATE
    when ANNEX_19_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_19_DATE
    when ANNEX_18_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_18_DATE
    when ANNEX_17_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_17_DATE
    when ANNEX_16_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_16_DATE
    when ANNEX_15_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_15_DATE
    when ANNEX_14_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_14_DATE
    when ANNEX_13_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_13_DATE
    when ANNEX_12_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_12_DATE
    when ANNEX_11_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_11_DATE
    when ANNEX_10_DATE<>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_10_DATE
    when ANNEX_9_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_9_DATE
    when ANNEX_8_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_8_DATE
    when ANNEX_7_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_7_DATE
    when ANNEX_6_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_6_DATE
    when ANNEX_5_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_5_DATE
    when ANNEX_4_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_4_DATE
    when ANNEX_3_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_3_DATE
    when ANNEX_2_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_2_DATE
    when ANNEX_1_DATE <>to_date ('19000101', 'yyyy-mm-dd') then ANNEX_1_DATE
    
    ELSE 'N/A'

Also I would probably replace it with coalesce(nullif(...)...) to make it easier and shorter:另外我可能会用 coalesce(nullif(...)...) 替换它，以使其更容易和更短：

coalesce(
   nullif(ANNEX_20_DATE, date'1900-01-01'),
   nullif(ANNEX_19_DATE, date'1900-01-01'),
   nullif(ANNEX_18_DATE, date'1900-01-01'),
   nullif(ANNEX_17_DATE, date'1900-01-01'),
   nullif(ANNEX_16_DATE, date'1900-01-01'),
   nullif(ANNEX_15_DATE, date'1900-01-01'),
   nullif(ANNEX_14_DATE, date'1900-01-01'),
   nullif(ANNEX_13_DATE, date'1900-01-01'),
   nullif(ANNEX_12_DATE, date'1900-01-01'),
   nullif(ANNEX_11_DATE, date'1900-01-01'),
   nullif(ANNEX_10_DATE, date'1900-01-01'),
   nullif(ANNEX_9_DATE , date'1900-01-01'),
   nullif(ANNEX_8_DATE , date'1900-01-01'),
   nullif(ANNEX_7_DATE , date'1900-01-01'),
   nullif(ANNEX_6_DATE , date'1900-01-01'),
   nullif(ANNEX_5_DATE , date'1900-01-01'),
   nullif(ANNEX_4_DATE , date'1900-01-01'),
   nullif(ANNEX_3_DATE , date'1900-01-01'),
   nullif(ANNEX_2_DATE , date'1900-01-01'),
   nullif(ANNEX_1_DATE , date'1900-01-01')
)

暂无
暂无

声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

相关问题 如何用SQL遍历一个表以寻找最接近的最大日期？ - How to loop through a table with SQL looking for closest max date? SQL 遍历表和列以查找哪些列不是空的 - SQL Loop through tables and columns to find which columns are NOT empty 循环遍历列SQL - Loop through columns SQL SQL查询找到最大日期 - SQL Query to find MAX Date SQL GROUP BY 查找最大日期 - SQL GROUP BY find max date SQL查找具有最大日期的项目 - SQL find items with max date 选择max（date）和表名作为列 - select the max(date) and table name as columns 动态循环 SQL 列 - Loop through SQL columns Dynamically SQL选择日期不为空的最大列数 - SQL Select Max of Columns Where Date is Not Null 查找所有列的最小最大值，而不在SQL中列出每个列名称 - Find min max over all columns without listing down each column name in SQL
相关标签
 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM