MyBatis inserts one to many relationship - insert

Question

I have my very simple one (Question) to many (Options) relationship, Option has the FK (questionId) to Question, now I'm going to insert a Question object with a list of Options inside within one XML configuration.
Question:
public Class Question{
...
private Integer questionId;
private List<Option> options;
....
}
Option:
public Class Option{
...
private Integer optionId;
private String context;
private Integer questionId; //FK
....
}
The configuration:
...
<insert id="insertQuestion" parameterType="com.pojos.Question" useGeneratedKeys="true">
INSERT into question (...) VALUES (...);
<selectKey keyColumn="questionId" keyProperty="questionId" resultType="int">
SELECT MAX(questionId) FROM question;
</selectKey>
INSERT INTO option (context, questionId)
VALUES
<foreach collection="options" item="option" open="(" separator="),(" close=")">
#{option.context}, #{questionId}
</foreach>
</insert>
...
As you can see, I'd like to use the just auto-generated questionId as the FK info for the options, however it doesn't work through, how can I make it work? or I cannot put them into a single scope?

Answer 1

In java 8 you could use default interface methods.
First you need to separate the operation with something like this:
Main table:
INSERT into question (...) VALUES (...);
<selectKey keyColumn="questionId" keyProperty="questionId" resultType="int">
SELECT MAX(questionId) FROM question;
</selectKey>
One to many relationship
INSERT INTO option (context, questionId)
VALUES
<foreach collection="options" item="option" open="(" separator="),(" close=")">
#{option.context}, #{questionId}
</foreach>
Then in your interface you will have at least three methods: insertQuestion, insertQuestionOptions and the default method (you could call it insertQuestionWithOptions for example) which uses both methods to insert it.
public interface QuestionDao {
int insertQuestion(Question question);
int insertOptions(List<Option> options);
default int insertQuestionsWithOptions(Question question) {
insertQuestion(question);
insertOptions(question.getOptions());
}
}
So, now you can use the method insertQuestionsWithOptions(Question question) which will insert question and options one to many relationship.