RaqForum 41 No.
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Split values of a field in a database table and transform it to new fields

 

Below is a table queried from BigQuery database. Its 4th field has comma-separated strings.

user_id

fst_name

lst_name

team_list

1111

DANNY

CRUISE

TEAM34,TEAM12,TEAM4

2222

CARLOS

SMITH

TEAM34,TEAM44,TEAM12

33333

SASHA

CONOR

TEAM5,TEAM34,TEAM44

Use Java to do this: Retain the first 3 fields, split values the 4th field, make the distinct values names of the fields from 4th to Nth, write 1 or 0 under each new field to record whether they are originally included in the current row or not, and save result as a new file. Below is the expected result:

user_id,fst_name,lst_name,TEAM34,TEAM12,TEAM4,TEAM44,TEAM5

1111,DANNY,CRUISE,1,1,1,0,0

2222,CARLOS,SMITH,1,1,0,1,0

33333,SASHA,CONOR,1,0,0,1,1

Write SPL code as follows:

A

1

=bigqry1.query("select user_id,fst_name,lst_name,team_list from data where p=1")

2

=A1.news(team_list.split@c();user_id,fst_name,lst_name,~)

3

=A2.pivot@s(#1,#2,#3; #4,if(#4,1,0))

4

=T("d:/result.csv":A3)

A1: Query the database through JDBC.

A2: Split up each value of the 4th field and generate a record for each distinct value; ~ is the current item.

A3: Perform row-to-column transposition – retain the first 3 columns, transform values of the 4th column to the new field names, and write 1 under each new field if they are included in the current row in the original table and 0 if they are not.

A4: Write result to a csv file.

Read How to Call a SPL Script in Java to find how to integrate SPL into a Java application.
Source:https://stackoverflow.com/questions/74645043/how-do-i-write-csv-file-with-dynamic-headers-in-apache-beam-java


 
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