MyBatis实现if-else的示例代码

mybaits 中没有else要用chose when otherwise 代替。

语法格式：
<choose>
    <when test="">
        //...
    </when>
    <otherwise>
        //...
    </otherwise>
</choose>

    <sql id="pageQueryOrder">
        <choose>
            <when test="sortField != null and sortField != ''">
                order by #{sortField}
                <if test="positiveOrReverse != null and positiveOrReverse != ''">
                    #{positiveOrReverse}
                </if>
                limit #{offset}, #{pageSize}
            </when>
            <otherwise>
                order by create_time desc limit #{offset}, #{pageSize}
            </otherwise>
        </choose>
    </sql>

<select id="selectUsersByStatus" resultType="User">
    SELECT * FROM users
    <where>
        <choose>
            <when test="status == 'ACTIVE'">
                AND status = 'ACTIVE'
            </when>
            <when test="status == 'INACTIVE'">
                AND status = 'INACTIVE'
            </when>
            <otherwise>
                AND status IS NULL
            </otherwise>
        </choose>
    </where>
</select>

<select id="selectUsersByType" resultType="User">
    SELECT * FROM users
    <where>
        <if test="userType != null">
            AND (
                <if test="userType == 'ADMIN'">
                    type = 'ADMIN'
                </if>
                <if test="userType == 'USER'">
                    AND type = 'USER'
                </if>
            )
        </if>
    </where>
</select>