• 動態查詢

xml中程式碼
<select id="Selective" parameterType="com.***.***.entity.Doctor"
            resultMap="BaseResultMap">
        select
        *
        from doctor
        <where>
            <if test="id != null">
                AND id = #{id,jdbcType=VARCHAR}
            </if>
            <if test="name != null">
                AND name = #{name,jdbcType=CHAR}
            </if>
        </where>
</select>

id為對映類中方法名稱,where內條件根據需求增減.
 

•  分頁查詢

首先實體類繼承一個基類.

​實體類中建立基類BaseEntity
public BaseEntity() {
        HttpServletRequest request = ((ServletRequestAttributes) 
                           RequestContextHolder.currentRequestAttributes()).getRequest();
        String pageSizeStr = request.getParameter("pageSize");
        String pageNoStr = request.getParameter("pageNo");

        if (StringUtils.isNotBlank(pageSizeStr)) {
            int size = Integer.parseInt(pageSizeStr);
            this.pageSize = size > 0 ? size : PAGE_SIZE;

        } else {
            this.pageSize = PAGE_SIZE;
        }

        if (StringUtils.isNotBlank(pageNoStr)) {
            int number = Integer.parseInt(pageNoStr);
            this.pageNo = number > 0 ? number - 1 : PAGE_NO;
        } else {
            this.pageNo = PAGE_NO;
        }

        this.beginNo = pageNo * pageSize;
    }

}

需要分頁查詢的使其實體類繼承BaseEntity,實體類就會含有pageNo(頁碼),pageSize(每頁條數),beginNo(查詢起始條數)屬性.
 

           controller層傳入的引數需要含有pageNo,pageSize屬性.

xml中程式碼

<select id="selectLimit"  parameterType="com.***.***.entity.Doctor" 
    resultMap="BaseResultMap">
    select *
    from doctor
        <where>
            **************
        </where>
        limit #{beginNo},#{pageSize}
</select>

​