如何通过使用 shell 脚本选择所需的列来读取 CSV 文件？

Question

我有几个 CSV 文件需要合并到一个文件中。

幸运的是，所有文件都使用了主键。根据主键，我需要从选定列的多个文件中读取日期。

如何开始根据列名读入数据？

我认为下一个重要任务是如何读取多个文件，例如查询每个文件中存在的主键的访问表。

H1,Name, DOB,…. static information (columns from the csv 1 file)
SASH1,Auth#,State,Status,…. (columns from the csv 2 file)
SPLI,RequestedFromDate,Type,ServiceType,….. (columns from the csv 3 file)
CRLI,DateofReview,ReviewedBy,CriteriaMet,…. (columns from the csv 4 file)
ARLI,DateofReview,CriteriaMet,CriteriaSource,…. (columns from the csv 4 file)

output - 
H1,Name, DOB,….
SASH1,**OP0619**,NY,VOID ….. One-One - Main csv with primary key (first record)
SPLI,10/1/2019,DFG,Full,….. One-many records from file2 match primary key
SPLI,10/3/2019,DFG,Full,….. One-many records from file2 match primary key
SPLI,10/3/2019,DFG,Full,….. One-many records from file2 match primary key
CRLI,11/22/2019,Kim,Yes,….. One-many records from file3 match primary key
CRLI,11/23/2019,Jon,Yes,….. One-many records from file3 match primary key
.
.
H1,Name, DOB,…. 
SASH1,OP0586,NY,VOID ….. One-One Main csv with primary key (second record)
SPLI,1/1/2019,DE,Level2,….. One-many records from file2 match primary key
SPLI,1/3/2019,DFG,Full,….. One-many  records from file2 match primary key
SPLI,1/3/2019,DFG,Full,….. One-many  records from file2 match primary key
CRLI,5/22/2019,John,Yes,….. One-many records from file3 match primary key
CRLI,3/23/2019,Bill,Yes,….. One-many records from file3 match primary key

等等等等……

Answer 1

根据我对您的问题的理解，我已经达成了以下解决方案。

这是我的用例：-

声明了 3 个变量（稍后你可以用你的文件替换它们）并在下面的查询中执行相同的查询

var=abc,bcd,xyz,pqm
var2=qwe,asd,zxc,rty
var3=poi,lkj,mnb,ghj

echo "`echo $var|awk -F"," '{print $1}'`,`echo $var2|awk -F"," '{print $2}'`,`echo $var3|awk -F"," '{print $3}'`"

输出是：-

abc,asd,mnb