错误的写法：

<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">

    SELECT

    a.*,

    FROM

    tb_user a

    WHERE =

    <if test="ids != null and ids.size()!=0">

        AND a.id IN

        <foreach collection="ids" item="id" index="index"

                 open="(" close=")" separator=",">

            #{id}

        </foreach>

    </if>

    <if test="statusList != null and statusList.size()!=0">

        AND a.status IN

        <foreach collection="statusList" item="status" index="index"

                 open="(" close=")" separator=",">

            #{status}

        </foreach>

    </if>

    ORDER BY a.create_time desc

    LIMIT (#{pageNo}-)*#{pageSize},#{pageSize};  // 错误

</select>

在MyBatis中LIMIT之后的语句不允许的变量不允许进行算数运算，会报错。

正确的写法一：

<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">

    SELECT

    a.*,

    FROM

    tb_user a

    WHERE =

    <if test="ids != null and ids.size()!=0">

        AND a.id IN

        <foreach collection="ids" item="id" index="index"

                 open="(" close=")" separator=",">

            #{id}

        </foreach>

    </if>

    <if test="statusList != null and statusList.size()!=0">

        AND a.status IN

        <foreach collection="statusList" item="status" index="index"

                 open="(" close=")" separator=",">

            #{status}

        </foreach>

    </if>

    ORDER BY a.create_time desc

    LIMIT ${(pageNo-)*pageSize},${pageSize}; （正确）

</select>

正确的写法二：（推荐）

<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">

    SELECT

    a.*,

    FROM

    tb_user a

    WHERE =

    <if test="ids != null and ids.size()!=0">

        AND a.id IN

        <foreach collection="ids" item="id" index="index"

                 open="(" close=")" separator=",">

            #{id}

        </foreach>

    </if>

    <if test="statusList != null and statusList.size()!=0">

        AND a.status IN

        <foreach collection="statusList" item="status" index="index"

                 open="(" close=")" separator=",">

            #{status}

        </foreach>

    </if>

    ORDER BY a.create_time desc

    LIMIT #{offSet},#{limit}; （推荐，代码层可控）

</select>

分析：方法二的写法，需要再请求参数中额外设置两个get函数，如下：

@Data

public class QueryParameterVO {

    private List<String> ids;

    private List<Integer> statusList;

    // 前端传入的页码

    private int pageNo;  // 从1开始

    // 每页的条数

    private int pageSize;

    // 数据库的偏移

    private int offSet;

    // 数据库的大小限制

    private int limit;

    // 这里重写offSet和limit的get方法

    public int getOffSet() {

        return (pageNo-)*pageSize;

    }

    public int getLimit() {

        return pageSize;

    }

}

错误的写法：
<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">    SELECT    a.*,    FROM    tb_user a    WHERE 1=1    <if test="ids != null and ids.size()!=0">        AND a.id IN        <foreach collection="ids" item="id" index="index"                 open="(" close=")" separator=",">            #{id}        </foreach>    </if>    <if test="statusList != null and statusList.size()!=0">        AND a.status IN        <foreach collection="statusList" item="status" index="index"                 open="(" close=")" separator=",">            #{status}        </foreach>    </if>    ORDER BY a.create_time desc    LIMIT (#{pageNo}-1)*#{pageSize},#{pageSize};  // 错误</select>在MyBatis中LIMIT之后的语句不允许的变量不允许进行算数运算，会报错。正确的写法一：<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">    SELECT    a.*,    FROM    tb_user a    WHERE 1=1    <if test="ids != null and ids.size()!=0">        AND a.id IN        <foreach collection="ids" item="id" index="index"                 open="(" close=")" separator=",">            #{id}        </foreach>    </if>    <if test="statusList != null and statusList.size()!=0">        AND a.status IN        <foreach collection="statusList" item="status" index="index"                 open="(" close=")" separator=",">            #{status}        </foreach>    </if>    ORDER BY a.create_time desc    LIMIT ${(pageNo-1)*pageSize},${pageSize}; （正确）</select>正确的写法二：（推荐）<select id="queryMyApplicationRecord" parameterType="MyApplicationRequest" resultMap="myApplicationMap">    SELECT    a.*,    FROM    tb_user a    WHERE 1=1    <if test="ids != null and ids.size()!=0">        AND a.id IN        <foreach collection="ids" item="id" index="index"                 open="(" close=")" separator=",">            #{id}        </foreach>    </if>    <if test="statusList != null and statusList.size()!=0">        AND a.status IN        <foreach collection="statusList" item="status" index="index"                 open="(" close=")" separator=",">            #{status}        </foreach>    </if>    ORDER BY a.create_time desc    LIMIT #{offSet},#{limit}; （推荐，代码层可控）</select>分析：方法二的写法，需要再请求参数中额外设置两个get函数，如下：@Datapublic class QueryParameterVO {     private List<String> ids;     private List<Integer> statusList;     // 前端传入的页码    private int pageNo;  // 从1开始     // 每页的条数    private int pageSize;     // 数据库的偏移    private int offSet;     // 数据库的大小限制    private int limit;     // 这里重写offSet和limit的get方法    public int getOffSet() {        return (pageNo-1)*pageSize;    }     public int getLimit() {        return pageSize;    }}
--------------------- 作者：timchen525 来源：CSDN 原文：https://blog.csdn.net/timchen525/article/details/79647666 版权声明：本文为博主原创文章，转载请附上博文链接！