自定义sql分页的步骤
- Dao层定义查询接口,第一个参数必须为分页的参数Ipage,后面可带其他参数作为传入参数
- 定义自定义查询sql
网上很多博客里面写的多表sql分页查询没带参数,这里给一个带参数的列子
JAVA和xml文件如下:
myPageList为使用mybatisPlus写的,pageList和pageListCount为原始写法
可以看出myPageList跟pageListsql语句一模一样,只是第一个参数必须为Ipage
public interface WfPurchaseFrameDao extends SuperDao<WfPurchaseFrame> { List<WfPurchaseFrame> pageList(@Param("param") WfPurchaseFrameParam param); IPage<WfPurchaseFrame> myPageList(IPage<WfPurchaseFrame> page ,@Param("param") WfPurchaseFrameParam param); long pageListCount(@Param("param") WfPurchaseFrameParam param); }
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-////DTD Mapper 3.0//EN" "/dtd/">
<mapper namespace="">
<select parameterType=""
resultType="">
select t.*,inst.proc_inst_id processInstanceId
from t_wf_purchase_frame t
left join t_flow_inst inst on inst.business_id = t.apply_id
where t.`status` = '0'
and inst.proc_inst_status ='1'
<if test=" != null and != ''">
and t.apply_person like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_code like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_name like concat('%',#{},'%')
</if>
limit #{},#{}
</select>
<select parameterType="" resultType="">
select t.*,inst.proc_inst_id processInstanceId
from t_wf_purchase_frame t
left join t_flow_inst inst on inst.business_id = t.apply_id
where t.`status` = '0'
and inst.proc_inst_status ='1'
<if test=" != null and != ''">
and t.apply_person like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_code like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_name like concat('%',#{},'%')
</if>
</select>
<select parameterType=""
resultType="long">
select count(1)
from t_wf_purchase_frame t
left join t_flow_inst inst on inst.business_id = t.apply_id
where t.`status` = '0'
and inst.proc_inst_status ='1'
<if test=" != null and != ''">
and t.apply_person like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_code like concat('%',#{},'%')
</if>
<if test=" != null and != ''">
and t.project_name like concat('%',#{},'%')
</if>
</select>
</mapper>
调用 controller层 【省略Service部分】:这里只需要在调用时传递一个Page(long current, long size)即可
@PostMapping(value = "/pageList")
public BaseResponse<BaseResponseList<WfPurchaseFrame>> pageList(@RequestBody WfPurchaseFrameParam param){
BaseResponse<BaseResponseList<WfPurchaseFrame>>baseResponse=new BaseResponse<>();
Long page=
(())?:(());
Long limit=
(())?:(());
Page<WfPurchaseFrame> resultPage=new Page<>(page,limit);
// 这里不能使用QueryWrapper 来传递自定义参数
QueryWrapper<WfPurchaseFrame> queryWrapper=(param);
IPage<WfPurchaseFrame> resultList= (resultPage,param);
BaseResponseList<WfPurchaseFrame> baseResponseList=new BaseResponseList<>();
(());
(());
(baseResponseList);
return baseResponse;
}
上面代码中说了不能使用wrapper查询条件构造器,原因为什么呢
${} 解析时会自动在前面带上where关键字,并且条件构建时不会带上表别名