Question

I am using MyBatis with MySql in my project.

I have:

myField ENUM(‘yes’,’no’)

and I want to map in to java boolean value:

I know I can modify all mybatis templates, e.g.:

<update id="update">
UPDATE
myTable
   <set>
        ...
       <if test="myField != null">myField = <choose>
           <when test="myField == true">'yes'</when>
           <otherwise>'no'</otherwise>
           </choose>,
        </if>
        ...
    </set>
 WHERE
    ...
 </update>

But can I do this in more convenient way?

Answer 1

It seems the best way to solve this is to implement my own boolean type handler:

public class YesNoBooleanTypeHandler extends BaseTypeHandler<Boolean> {

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, Boolean parameter,      JdbcType jdbcType)
            throws SQLException {
        ps.setString(i, convert(parameter));
    }

    @Override
    public Boolean getNullableResult(ResultSet rs, String columnName)
            throws SQLException {
        return convert(rs.getString(columnName));
    }

    @Override
    public Boolean getNullableResult(ResultSet rs, int columnIndex)
            throws SQLException {
        return convert(rs.getString(columnIndex));
    }

    @Override
    public Boolean getNullableResult(CallableStatement cs, int columnIndex)
            throws SQLException {
        return convert(cs.getString(columnIndex));
    }

    private String convert(Boolean b) {
        return b ? "yes" : "no";
    }

    private Boolean convert(String s) {
        return s.equals("yes");
    }

}

and then to use it in the mapper template:

<update id="update">
UPDATE
myTable
   <set>
        ...
       <if test="myField != null">myField = #{myField ,typeHandler=YesNoBooleanTypeHandler}</if>
        ...
    </set>
 WHERE
    ...
 </update>