Mapping data using a subquery
The sample Job described in this scenario maps the data from two input tables, PreferredSubject and CourseScore, to the output table, TotalScoreOfPreferredSubject, using a subquery.
For more technologies supported by Talend, see Talend components.
Prerequisite
Ensure that you have added an Oracle database connection in the section prior to creating the Job. For more information, see Centralizing database connections.
The Standard Job and the Prejob design
In this scenario, design the Standard Job such as the following:
Design the Prejob that includes the data in this scenario as follows:
The PreferredSubject table contains the student's
preferred subject data. To reproduce this scenario, you can load the following data to
the Oracle table from a CSV
file:
SeqID;StuName;Subject;Detail
1;Amanda;art;Amanda prefers art.
2;Ford;science;Ford prefers science.
3;Kate;art;Kate prefers art.The CourseScore table contains the student's
subject score data. To reproduce this scenario, you can load the following data to the
Oracle table from a CSV
file:
SeqID;StuName;Subject;Course;Score;Detail
1;Amanda;science;math;85;science score
2;Amanda;science;physics;75;science score
3;Amanda;science;chemistry;80;science score
4;Amanda;art;chinese;85;art score
5;Amanda;art;history;95;art score
6;Amanda;art;geography;80;art score
7;Ford;science;math;95;science score
8;Ford;science;physics;85;science score
9;Ford;science;chemistry;80;science score
10;Ford;art;chinese;75;art score
11;Ford;art;history;80;art score
12;Ford;art;geography;85;art score
13;Kate;science;math;65;science score
14;Kate;science;physics;75;science score
15;Kate;science;chemistry;80;science score
16;Kate;art;chinese;85;art score
17;Kate;art;history;80;art score
18;Kate;art;geography;95;art scoreBefore the Job execution, the output table
TotalScoreOfPreferredSubject does not contain any
data:
SeqID;StuName;PreferredSubject;TotalScoreDid this page help you?
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