Using enum parameters in myBatis dynamic SQL

Question

How to do dynamic SQL in myBatis 3.1.1 based on an enum constant parameter?

Answer 1

How to do dynamic SQL based on enum constants

public enum Test {
    A, B;
}

Mapper.java:
    int test(@Param("t") Test t);

Mapper.xml:
    <select id="test" resultType="int">
        select
        <choose>
            <when test='t.name().equals("A")'>65</when>
            <when test='t.name().equals("B")'>66</when>
            <otherwise>0</otherwise>
        </choose>
    </select>   

Notes

• The test expression must refer to strings using double quotes, not single quotes.
• You can't compare constants, only strings.

Answer 2

MyBatis allows == instead of equals for strings in if (or when) statements. So the following would also work (quotes don't matter):

public enum Test {
    A, B;
}

Mapper.java:

int test(@Param("t") Test t);

Mapper.xml:

<select id="test" resultType="int">
    select
    <choose>
        <when test="t.name() == 'A'">65</when>
        <when test="t.name() == 'B'">66</when>
        <otherwise>0</otherwise>
    </choose>
</select>