一段SQL代码的压缩：从974行到96行，十倍压缩
涉及到数据库拆分，需要将相关表的JOIN SQL剥离。
剥离过程中，发现了这么个SQL XML。整个SQL 974 行，分为6个函数。读起来费劲无比。
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="VisitStatisticsDao">
<resultMap id="visitStatisticsResult" type="com.qunar.hotel.crm.dto.VisitStatisticsResult"/> <sql id="timeRange">
<![CDATA[
visit.visit_date >= #{dateFrom} ]]>
and
<![CDATA[ visit.visit_date <= #{dateTo} ]]>
</sql> <sql id="validState">
and
visit.valid = 1
</sql> <sql id="conditionOfSort">
<choose>
<when test="orderBy == 'byDoorVisited'">
and visit.visit_type = 2
</when>
<when test="orderBy == 'KPVisited'">
and visit.is_active = 0
</when>
<when test="orderBy == 'byDoorKPVisited'">
and visit.is_active = 0 and visit.visit_type =2
</when>
<when test="orderBy == 'revisited'">
and visit.revisit_valid = 1
</when>
</choose>
</sql> <sql id="statisticAttribute">
total_count.visit_count as totalVisited,
by_door_count.visit_count as byDoorVisited,
kp_count.visit_count as KPVisited,
by_door_kp_count.visit_count as byDoorKPVisited,
by_valid_revisit_count.visit_count as revisited
</sql> <sql id="order">
<choose>
<when test="orderBy == 'totalVisited'">
totalVisited
</when>
<when test="orderBy == 'byDoorVisited'">
byDoorVisited
</when>
<when test="orderBy == 'KPVisited'">
KPVisited
</when>
<when test="orderBy == 'byDoorKPVisited'">
byDoorKPVisited
</when>
<when test="orderBy == 'revisited'">
revisited
</when>
<otherwise>
totalVisited
</otherwise>
</choose>
<choose>
<when test="orderType == 'asc'">
asc
</when>
<otherwise>
desc
</otherwise>
</choose>
</sql> <sql id="parent">
(select
`id`,
`name`,
`tree_code`,
`org_type`
from qadmin_org org
where org_type = #{dimension}
and org.tree_code like concat((select tree_code from qadmin_org where id = #{groupId}), '%')
)
parent
</sql> <sql id="orgVisitRecord">
qadmin_org org
left join
qadmin_user user
on org.id = user.org_id
inner join
crm_visit_record visit
on user.user_id = visit.user_id
where
<include refid="timeRange"/>
<include refid="validState"/>
</sql> <sql id="bdTotalCount">
(select
count(visit.id) visit_count,
user.user_id user_id,
user.realname real_name
from
qadmin_org org
inner join
qadmin_user user on user.org_id = org.id
left join
(select id, user_id from
crm_visit_record visit
where
<include refid="timeRange"/>
<include refid="validState"/>
)
visit
on visit.user_id = user.user_id
where
org.tree_code like concat((select tree_code from qadmin_org where id=#{groupId}), '%')
group by
user.user_id
)
</sql> <sql id="bdByDoorCount">
(select
count(visit.id) visit_count,
user.user_id user_id,
user.realname real_name
from
qadmin_org org
inner join
qadmin_user user on user.org_id = org.id
left join
(select id, user_id from
crm_visit_record visit
where
<include refid="timeRange"/>
and
visit_type = 2
<include refid="validState"/>
)
visit on visit.user_id = user.user_id
where
org.tree_code like concat((select tree_code from qadmin_org where id=#{groupId}), '%')
group by
user.user_id
)
</sql> <sql id="bdKPCount">
(select
count(visit.id) visit_count,
user.user_id user_id,
user.realname real_name
from
qadmin_org org
inner join
qadmin_user user on user.org_id = org.id
left join
(select id, user_id from
crm_visit_record visit
where
<include refid="timeRange"/>
and
is_active = 0
<include refid="validState"/>
)
visit on visit.user_id = user.user_id
where
org.tree_code like concat((select tree_code from qadmin_org where id=#{groupId}), '%')
group by
user.user_id
)
</sql> <sql id="bdKPByDoorCount">
(select
count(visit.id) visit_count,
user.user_id user_id,
user.realname real_name
from
qadmin_org org
inner join
qadmin_user user on user.org_id = org.id
left join
(select id, user_id from
crm_visit_record visit
where
<include refid="timeRange"/>
and
is_active = 0
and
visit_type = 2
<include refid="validState"/>
)
visit on visit.user_id = user.user_id
where
org.tree_code like concat((select tree_code from qadmin_org where id=#{groupId}), '%')
group by
user.user_id
)
</sql> <sql id="RevisitValidCount">
(
select
count(visit.id) visit_count,
user.user_id user_id,
user.realname real_name
from
qadmin_org org
inner join
qadmin_user user on user.org_id = org.id
left join
(select id, user_id from crm_visit_record visit
where
<include refid="timeRange"/>
<include refid="validState"/>
and
revisit_valid = 1
)
visit on visit.user_id = user.user_id
where
org.tree_code like concat((select tree_code from qadmin_org where id=#{groupId}), '%')
group by
user.user_id
)
</sql> <sql id="queryBDVisitedCountInMultiGroupTotal">
(
select
org.id as 'id',
org.user_id as 'user_id',
org.sub_realname as 'name',
visit.visit_count as 'visit_count'
from
(
select
sub.id as 'id',
sub.user_id as 'user_id',
sub.realname as 'sub_realname'
from
(select id, name, tree_code from qadmin_org)
parent
left join
(select
org.name,
org.tree_code,
user.id as 'id',
user.user_id as 'user_id',
user.realname
from
qadmin_org
org
inner join
qadmin_user user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
org
left join
(
select
count(visit.id) as 'visit_count',
user.user_id as 'user_id'
from
crm_visit_record visit
left join
qadmin_user user
on
visit.user_id = user.user_id
where
<include refid="timeRange"/>
<include refid="validState"/>
group by
user.user_id
)
visit
on org.user_id = visit.user_id
)
</sql> <sql id="queryBDVisitedCountInMultiGroupByDoor">
(
select
org.id as 'id',
org.user_id as 'user_id',
org.sub_realname as 'name',
visit.visit_count as 'visit_count'
from
(
select
sub.id as 'id',
sub.user_id as 'user_id',
sub.realname as 'sub_realname'
from
(select id, name, tree_code from qadmin_org)
parent
left join
(select
org.name,
org.tree_code,
user.id as 'id',
user.user_id as 'user_id',
user.realname
from
qadmin_org
org
inner join
qadmin_user user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
org
left join
(
select
count(visit.id) as 'visit_count',
user.user_id as 'user_id'
from
crm_visit_record visit
left join
qadmin_user user
on
visit.user_id = user.user_id
where
<include refid="timeRange"/>
and
visit.visit_type = 2
<include refid="validState"/>
group by
user.user_id
)
visit
on org.user_id = visit.user_id
)
</sql> <sql id="queryBDVisitedCountInMultiGroupByKPVisit">
(
select
org.id as 'id',
org.user_id as 'user_id',
org.sub_realname as 'name',
visit.visit_count as 'visit_count'
from
(
select
sub.id as 'id',
sub.user_id as 'user_id',
sub.realname as 'sub_realname'
from
(select id, name, tree_code from qadmin_org)
parent
left join
(
select
org.name,
org.tree_code,
user.id as 'id',
user.user_id as 'user_id',
user.realname
from
qadmin_org
org
inner join
qadmin_user
user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
org
left join
(
select
count(visit.id) as 'visit_count',
user.user_id as 'user_id'
from
crm_visit_record visit
left join
qadmin_user user
on
visit.user_id = user.user_id
where
<include refid="timeRange"/>
and
visit.is_active = 0
<include refid="validState"/>
group by
user.user_id
)
visit
on org.user_id = visit.user_id
)
</sql> <sql id="queryBDVisitedCountInMultiGroupByKPDoorVisit">
(
select
org.id as 'id',
org.user_id as 'user_id',
org.sub_realname as 'name',
visit.visit_count as 'visit_count'
from
(
select
sub.id as 'id',
sub.user_id as 'user_id',
sub.realname as 'sub_realname'
from
(select id, name, tree_code from qadmin_org)
parent
left join
(
select
org.name,
org.tree_code,
user.id as 'id',
user.user_id as 'user_id',
user.realname
from
qadmin_org
org
inner join
qadmin_user
user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
org
left join
(
select
count(visit.id) as 'visit_count',
user.user_id as 'user_id'
from
crm_visit_record visit
left join
qadmin_user user
on
visit.user_id = user.user_id
where
<include refid="timeRange"/>
and
visit.is_active = 0
and
visit.visit_type = 2
<include refid="validState"/>
group by
user.user_id
)
visit
on org.user_id = visit.user_id
)
</sql> <sql id="queryBDVisitedCountInMultiGroupByValidRevisit">
(
select
org.id as 'id',
org.user_id as 'user_id',
org.sub_realname as 'name',
visit.visit_count as 'visit_count'
from
(
select
sub.id as 'id',
sub.user_id as 'user_id',
sub.realname as 'sub_realname'
from
(select id, name, tree_code from qadmin_org)
parent
left join
(
select
org.name,
org.tree_code,
user.id as 'id',
user.user_id as 'user_id',
user.realname
from
qadmin_org
org
inner join
qadmin_user
user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
org
left join
(
select
count(visit.id) as 'visit_count',
user.user_id as 'user_id'
from
crm_visit_record visit
left join
qadmin_user user
on
visit.user_id = user.user_id
where
<include refid="timeRange"/>
and
visit.revisit_valid = 1
<include refid="validState"/>
group by
user.user_id
)
visit
on org.user_id = visit.user_id
)
</sql> <select id="querySortedBDVisitStatistics" parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition" resultType="string">
select user_id from
(
select
visit.user_id as 'user_id',
visit.visit_count as 'visit_count'
from
(
select
sub.user_id as 'user_id'
from
(select id, tree_code from qadmin_org)
parent
left join
(
select
org.tree_code as 'tree_code',
user.user_id as 'user_id'
from
qadmin_org
org
inner join
qadmin_user user
on user.org_id = org.id
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
)
user
left join
(
select
count(visit.id) as 'visit_count',
user_id
from crm_visit_record visit
where
<include refid="timeRange"/>
<include refid="validState"/>
<include refid="conditionOfSort"/>
group by user_id
)
visit
on user.user_id = visit.user_id
order by visit_count
<choose>
<when test="orderType == 'asc'">
asc
</when>
<otherwise>
desc
</otherwise>
</choose>
)temp </select> <select id="queryBDVisitedCount" resultMap="visitStatisticsResult"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition"
fetchSize="100" resultSetType="FORWARD_ONLY">
select
total_count.user_id as groupId,
total_count.real_name as name,
<include refid="statisticAttribute"/>
from <include refid="bdTotalCount"/>
total_count
left join
<include refid="bdByDoorCount"/>
by_door_count
on total_count.user_id = by_door_count.user_id
left join
<include refid="bdKPCount"/>
kp_count
on total_count.user_id = kp_count.user_id
left join
<include refid="bdKPByDoorCount"/>
by_door_kp_count
on total_count.user_id = by_door_kp_count.user_id
left join
<include refid="RevisitValidCount"/>
by_valid_revisit_count
on total_count.user_id = by_valid_revisit_count.user_id
order by
<include refid="order"/>
</select> <select id="queryOrgVisitedCount" resultMap="visitStatisticsResult"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition"
fetchSize="100" resultSetType="FORWARD_ONLY">
select
total_count.parent_id as 'groupId',
total_count.parent_name as 'name',
<include refid="statisticAttribute"/>
from
(
select
parent.id as 'parent_id',
parent.name as 'parent_name',
count(sub.visit_id) as 'visit_count'
from
<include refid="parent"/>
left join
(select
org.tree_code as 'tree_code',
visit.id as 'visit_id'
from
<include refid="orgVisitRecord"/>
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
group by parent.id)
total_count
left join
(
select
parent.id as 'parent_id',
parent.name as 'parent_name',
count(sub.visit_id) as 'visit_count'
from
<include refid="parent"/>
left join
(select
org.tree_code as 'tree_code',
visit.id as 'visit_id'
from
<include refid="orgVisitRecord"/>
and visit.visit_type = 2
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
group by parent.id)
by_door_count
on total_count.parent_id = by_door_count.parent_id
left join
(
select
parent.id as 'parent_id',
parent.name as 'parent_name',
count(sub.visit_id) as 'visit_count'
from
<include refid="parent"/>
left join
(select
org.tree_code as 'tree_code',
visit.id as 'visit_id'
from
<include refid="orgVisitRecord"/>
and visit.is_active = 0
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
group by parent.id)
kp_count
on total_count.parent_id = kp_count.parent_id
left join
(
select
parent.id as 'parent_id',
parent.name as 'parent_name',
count(sub.visit_id) as 'visit_count'
from
<include refid="parent"/>
left join
(select
org.tree_code as 'tree_code',
visit.id as 'visit_id'
from
<include refid="orgVisitRecord"/>
and visit.is_active = 0
and visit.visit_type = 2
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
group by parent.id)
kp_by_door_count
on total_count.parent_id = kp_by_door_count.parent_id
left join
(
select
parent.id as 'parent_id',
parent.name as 'parent_name',
count(sub.visit_id) as 'visit_count'
from
<include refid="parent"/>
left join
(
select
org.tree_code as 'tree_code',
visit.id as 'visit_id'
from
<include refid="orgVisitRecord"/>
and visit.revisit_valid = 1
)
sub
on sub.tree_code like concat(parent.tree_code, '%')
group by parent.id
)
by_valid_revisit_count
on total_count.parent_id = by_valid_revisit_count.parent_id
order by
<include refid="order"/>
</select> <select id="querySingleBDVisitedCount" resultMap="visitStatisticsResult"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition">
select
total_count.user_id as groupId,
total_count.name as name,
<include refid="statisticAttribute"/>
from
(
select
count(visit.id) as visit_count,
user.user_id as user_id,
user.realname as name
from
qadmin_user user
left join
crm_visit_record visit
on user.user_id = visit.user_id
where
user.user_id = #{groupId}
and
<include refid="timeRange"/>
<include refid="validState"/>
)
total_count
left join
(
select
count(visit.id) as visit_count,
user.user_id as user_id,
user.realname as name
from
qadmin_user user
left join
crm_visit_record visit
on user.user_id = visit.user_id
where
user.user_id = #{groupId}
and
<include refid="timeRange"/>
<include refid="validState"/>
and
visit.visit_type = 2
)
by_door_count
on total_count.user_id = by_door_count.user_id
left join
(
select
count(visit.id) as visit_count,
user.user_id as user_id,
user.realname as name
from
qadmin_user user
left join
crm_visit_record visit
on user.user_id = visit.user_id
where
user.user_id = #{groupId}
and
<include refid="timeRange"/>
<include refid="validState"/>
and
visit.is_active = 0
)
kp_count
on total_count.user_id = kp_count.user_id
left join
(
select
count(visit.id) as visit_count,
user.user_id as user_id,
user.realname as name
from
qadmin_user user
left join
crm_visit_record visit
on user.user_id = visit.user_id
where
user.user_id = #{groupId}
and
<include refid="timeRange"/>
<include refid="validState"/>
and
visit.is_active = 0
and
visit.visit_type = 2
)
by_door_kp_count
on total_count.user_id = by_door_kp_count.user_id
left join
(
select
count(visit.id) as visit_count,
user.user_id as user_id,
user.realname as name
from
qadmin_user user
left join
crm_visit_record visit
on user.user_id = visit.user_id
where
user.user_id = #{groupId}
and
<include refid="timeRange"/>
<include refid="validState"/>
and
visit.revisit_valid = 1 )
by_valid_revisit_count
on total_count.user_id = by_valid_revisit_count.user_id </select> <select id="queryBDVisitedCountInMultiGroup" resultMap="visitStatisticsResult"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition"
fetchSize="100" resultSetType="FORWARD_ONLY">
select
total_count.user_id as 'groupId',
total_count.name as 'name',
<include refid="statisticAttribute"/>
from
<include refid="queryBDVisitedCountInMultiGroupTotal"/>
total_count
left join
<include refid="queryBDVisitedCountInMultiGroupByDoor"/>
by_door_count
on
total_count.user_id = by_door_count.user_id
left join
<include refid="queryBDVisitedCountInMultiGroupByKPVisit"/>
kp_count
on total_count.user_id = kp_count.user_id
left join
<include refid="queryBDVisitedCountInMultiGroupByKPDoorVisit"/>
by_door_kp_count
on total_count.user_id = by_door_kp_count.user_id
left join
<include refid="queryBDVisitedCountInMultiGroupByValidRevisit"/>
by_valid_revisit_count
on total_count.user_id = by_valid_revisit_count.user_id
group by total_count.user_id
order by
<include refid="order"/>
</select> <select id="queryBDVisitedRecordSize" resultType="int"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition">
select count(distinct sub.user_id) from
(select id, tree_code from qadmin_org)
parent
left join
(select
org.tree_code as 'tree_code',
`user`.id as 'user_id'
from
qadmin_org org left join
qadmin_user `user`
on `user`.org_id = org.id)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id = #{groupId};
</select> <select id="queryOrgVisitedRecordSize" resultType="int"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition">
select count(sub.id) from
(select
name,
id,
org_type,
tree_code
from qadmin_org where id = #{groupId})
parent
left join
(select
name,
id,
org_type,
tree_code
from qadmin_org where org_type = #{dimension})
sub
on sub.tree_code like concat(parent.tree_code, '%');
</select> <select id="queryBDVisitedInMultiGroupRecordSize" resultType="int"
parameterType="com.qunar.hotel.crm.model.condition.VisitStatisticsCondition">
select
count(sub.id)
from
(select id, name, tree_code from qadmin_org)
parent
left join
(select
org.name,
org.tree_code,
user.id,
user.realname
from
qadmin_org org inner join
qadmin_user user
on user.org_id = org.id)
sub
on sub.tree_code like concat(parent.tree_code, '%')
where
parent.id in
<foreach collection="groupIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
</select> </mapper>
花费了半天的分析后，重构代码，SQL压缩为96行
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qunar.scm.visit.dao.VisitStatisticsDao">
<resultMap id="visitStatisticsResult" type="com.qunar.scm.visit.model.vo.VisitStatisticsResult"/> <sql id="order">
<choose>
<when test="orderBy == 'totalVisited'">
totalVisited
</when>
<when test="orderBy == 'byDoorVisited'">
byDoorVisited
</when>
<when test="orderBy == 'KPVisited'">
KPVisited
</when>
<when test="orderBy == 'byDoorKPVisited'">
byDoorKPVisited
</when>
<when test="orderBy == 'revisited'">
revisited
</when>
<otherwise>
totalVisited
</otherwise>
</choose>
<choose>
<when test="orderType == 'asc'">
asc
</when>
<otherwise>
desc
</otherwise>
</choose>
</sql> <sql id="where">
<where>
visit.visit_date >= #{dateFrom} and #{dateTo} >= visit.visit_date
and visit.valid = 1
<if test="userId != null and userId != '' ">
and user_id = #{userId}
</if>
<if test="orgTreeCodes != null and orgTreeCodes.size >0 ">
AND
<foreach collection="orgTreeCodes" item="treeCode" open="(" close=")" separator="or">
org_tree_code like '${treeCode}%'
</foreach>
</if>
</where>
</sql> <sql id="column">
user_id as 'groupId',
count(1) as totalVisited,
sum(case when visit.visit_type =2 then 1 else 0 end) as byDoorVisited,
sum(case when visit.is_active = 0 then 1 else 0 end) as KPVisited,
sum(case when visit.is_active = 0 and visit.visit_type =2 then 1 else 0 end) as byDoorKPVisited,
sum(case when visit.revisit_valid = 1 then 1 else 0 end) as revisited,
sum(case when (visit.visit_purpose_type = '1' or visit.visit_purpose_type='1#2') then 1 else 0 end) as visitforSignCount,
sum(case when (visit.visit_purpose_type = '2' or visit.visit_purpose_type='1#2') then 1 else 0 end) as visitforMantainceCount
</sql> <select id="queryBDVisitedCountInMultiGroupWithRowHandler" resultMap="visitStatisticsResult"
parameterType="com.qunar.scm.visit.model.condition.VisitStatisticsCondition"
fetchSize="100" resultSetType="FORWARD_ONLY">
select
<include refid="column"/>
from crm_visit_record visit
<include refid="where"/>
group by user_id
order by
<include refid="order"/>
</select> <select id="queryBDVisitedCountInMultiGroup" resultMap="visitStatisticsResult"
parameterType="com.qunar.scm.visit.model.condition.VisitStatisticsCondition">
select
<include refid="column"/>
from crm_visit_record visit
<include refid="where"/>
group by user_id
order by
<include refid="order"/>
</select> <select id="queryBDVisitedInMultiGroupRecordSize" resultType="int"
parameterType="com.qunar.scm.visit.model.condition.VisitStatisticsCondition">
select
count(distinct user_id)
from crm_visit_record visit
<include refid="where"/>
</select> </mapper>
简要分析：
整个SQL分类：
1 6个函数，count 3个，select list 3个，where条件分别为查单独一个人，查一个组织。6个函数完全可以压缩为2个函数。
2 原SQL原理
先生成多个统计指标的temp表，然后使用uid进行left join
select count(1) from A where W1
left join
select count(1) from A where W2
left join
select count(1) from A where W3
order by XXXXX
换一种思路 使用CASE WHEN代替即可
select
SUM(case when W1 then 1 else 0 end),
SUM(case when W2 then 1 else 0 end),
SUM(case when W3 then 1 else 0 end)
FROM A
ORDER BY XXXX
挫代码处处有，也许一开始是不挫的，随着一代代不加思考叠加，最终就成了没法维护的代码。所以，对于Coding，无论何时，保持一个谨慎的态度。
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