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ibatis常用sql
(1) 输入参数为单个值
Xml代码

<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore"

parameterClass="long">

delete from

MemberAccessLog

where

accessTimestamp = #value#

</delete>
```
<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore" 
parameterClass="long"> 
delete from 
MemberAccessLog 
where 
accessTimestamp = #value# 
</delete> 
```
(2) 输入参数为一个对象
Xml代码

<insert id="com.fashionfree.stat.accesslog.MemberAccessLog.insert"

parameterClass="com.fashionfree.stat.accesslog.model.MemberAccessLog>

insert into MemberAccessLog

(

accessLogId, memberId, clientIP,

httpMethod, actionId, requestURL,

accessTimestamp, extend1, extend2,

extend3

)

values

(

#accessLogId#, #memberId#,

#clientIP#, #httpMethod#,

#actionId#, #requestURL#,

#accessTimestamp#, #extend1#,

#extend2#, #extend3#

)

</insert>
```
<insert id="com.fashionfree.stat.accesslog.MemberAccessLog.insert" 
parameterClass="com.fashionfree.stat.accesslog.model.MemberAccessLog> 
insert into MemberAccessLog 
( 
accessLogId, memberId, clientIP, 
httpMethod, actionId, requestURL, 
accessTimestamp, extend1, extend2, 
extend3 
) 
values 
( 
#accessLogId#, #memberId#, 
#clientIP#, #httpMethod#, 
#actionId#, #requestURL#, 
#accessTimestamp#, #extend1#, 
#extend2#, #extend3# 
) 
</insert> 
```
(3) 输入参数为一个java.util.HashMap
Xml代码

<select id="com.fashionfree.stat.accesslog.selectActionIdAndActionNumber"

parameterClass="hashMap"

resultMap="getActionIdAndActionNumber">

select

actionId, count(*) as count

from

MemberAccessLog

where

memberId = #memberId#

and accessTimestamp > #start#

and accessTimestamp <= #end#

group by actionId

</select>
```
<select id="com.fashionfree.stat.accesslog.selectActionIdAndActionNumber" 
parameterClass="hashMap" 
resultMap="getActionIdAndActionNumber"> 
select 
actionId, count(*) as count 
from 
MemberAccessLog 
where 
memberId = #memberId# 
and accessTimestamp &gt; #start# 
and accessTimestamp &lt;= #end# 
group by actionId 
</select>
```
(4) 输入参数中含有数组
Xml代码

<insert id="updateStatusBatch" parameterClass="hashMap">

update

Question

set

status = #status#

<dynamic prepend="where questionId in">

<isNotNull property="actionIds">

<iterate property="actionIds" open="(" close=")" conjunction=",">

#actionIds[]#

</iterate>

</isNotNull>

</dynamic>

</insert>
```
<insert id="updateStatusBatch" parameterClass="hashMap"> 
update 
Question 
set 
status = #status# 
<dynamic prepend="where questionId in"> 
<isNotNull property="actionIds"> 
<iterate property="actionIds" open="(" close=")" conjunction=","> 
#actionIds[]# 
</iterate> 
</isNotNull> 
</dynamic> 
</insert> 
```
   说明：actionIds为传入的数组的名字；
   使用dynamic标签避免数组为空时导致sql语句语法出错；
   使用isNotNull标签避免数组为null时ibatis解析出错

   (5)传递参数只含有一个数组
Xml代码

<select id="com.fashionfree.stat.accesslog.model.StatMemberAction.selectActionIdsOfModule"

resultClass="hashMap">

select

moduleId, actionId

from

StatMemberAction

<dynamic prepend="where moduleId in">

<iterate open="(" close=")" conjunction=",">

#[]#

</iterate>

</dynamic>

order by

moduleId

</select>
```
<select id="com.fashionfree.stat.accesslog.model.StatMemberAction.selectActionIdsOfModule" 
resultClass="hashMap"> 
select 
moduleId, actionId 
from 
StatMemberAction 
<dynamic prepend="where moduleId in"> 
<iterate open="(" close=")" conjunction=","> 
#[]# 
</iterate> 
</dynamic> 
order by 
moduleId 
</select> 
```
    说明：注意select的标签中没有parameterClass一项
       另：这里也可以把数组放进一个hashMap中，但增加额外开销，不建议使用

   (6)让ibatis把参数直接解析成字符串
Xml代码

<select id="com.fashionfree.stat.accesslog.selectSumDistinctCountOfAccessMemberNum"

parameterClass="hashMap" resultClass="int">

select

count(distinct memberId)

from

MemberAccessLog

where

accessTimestamp >= #start#

and accessTimestamp < #end#

and actionId in $actionIdString$

</select>
```
<select id="com.fashionfree.stat.accesslog.selectSumDistinctCountOfAccessMemberNum" 
parameterClass="hashMap" resultClass="int"> 
select 
count(distinct memberId) 
from 
MemberAccessLog 
where 
accessTimestamp &gt;= #start# 
and accessTimestamp &lt; #end# 
and actionId in $actionIdString$ 
</select>
```
    说明：使用这种方法存在sql注入的风险，不推荐使用

   (7)分页查询 (pagedQuery)
Java代码

<select id="com.fashionfree.stat.accesslog.selectMemberAccessLogBy"

parameterClass="hashMap" resultMap="MemberAccessLogMap">

<include refid="selectAllSql"/>

<include refid="whereSql"/>

<include refid="pageSql"/>

</select>

<select id="com.fashionfree.stat.accesslog.selectMemberAccessLogBy.Count"

parameterClass="hashMap" resultClass="int">

<include refid="countSql"/>

<include refid="whereSql"/>

</select>

<sql id="selectAllSql">

select

accessLogId, memberId, clientIP,

httpMethod, actionId, requestURL,

accessTimestamp, extend1, extend2,

extend3

from

MemberAccessLog

</sql>

<sql id="whereSql">

accessTimestamp <= #accessTimestamp#

</sql>

<sql id="countSql">

select

count(*)

from

MemberAccessLog

</sql>

<sql id="pageSql">

<dynamic>

<isNotNull property="startIndex">

<isNotNull property="pageSize">

limit #startIndex# , #pageSize#

</isNotNull>

</isNotNull>

</dynamic>

</sql>
```
<select id="com.fashionfree.stat.accesslog.selectMemberAccessLogBy" 
parameterClass="hashMap" resultMap="MemberAccessLogMap"> 
<include refid="selectAllSql"/> 
<include refid="whereSql"/> 
<include refid="pageSql"/> 
</select> 
<select id="com.fashionfree.stat.accesslog.selectMemberAccessLogBy.Count" 
parameterClass="hashMap" resultClass="int"> 
<include refid="countSql"/> 
<include refid="whereSql"/> 
</select> 
<sql id="selectAllSql"> 
select 
accessLogId, memberId, clientIP, 
httpMethod, actionId, requestURL, 
accessTimestamp, extend1, extend2, 
extend3 
from 
MemberAccessLog 
</sql> 
<sql id="whereSql"> 
accessTimestamp &lt;= #accessTimestamp# 
</sql> 
<sql id="countSql"> 
select 
count(*) 
from 
MemberAccessLog 
</sql> 
<sql id="pageSql"> 
<dynamic> 
<isNotNull property="startIndex"> 
<isNotNull property="pageSize"> 
limit #startIndex# , #pageSize# 
</isNotNull> 
</isNotNull> 
</dynamic> 
</sql> 
```
   说明：本例中，代码应为：
   HashMap hashMap = new HashMap();
   hashMap.put(“accessTimestamp”, someValue);
   pagedQuery(“com.fashionfree.stat.accesslog.selectMemberAccessLogBy”, hashMap);
   pagedQuery方法首先去查找名为com.fashionfree.stat.accesslog.selectMemberAccessLogBy.Count 的mapped statement来进行sql查询，从而得到com.fashionfree.stat.accesslog.selectMemberAccessLogBy查询的记录个数，
再进行所需的paged sql查询(com.fashionfree.stat.accesslog.selectMemberAccessLogBy)，具体过程参见utils类中的相关代码

(8)sql语句中含有大于号>、小于号<

    1. 将大于号、小于号写为： > < 如：
Xml代码

<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore" parameterClass="long">

delete from

MemberAccessLog

where

accessTimestamp <= #value#

</delete>
```
<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore" parameterClass="long"> 
delete from 
MemberAccessLog 
where 
accessTimestamp &lt;= #value# 
</delete> 
```
2. 将特殊字符放在xml的CDATA区内：
Xml代码

<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore" parameterClass="long">

<![CDATA[

delete from

MemberAccessLog

where

accessTimestamp <= #value#

]]>

</delete>
```
<delete id="com.fashionfree.stat.accesslog.deleteMemberAccessLogsBefore" parameterClass="long"> 
<![CDATA[ 
delete from 
MemberAccessLog 
where 
accessTimestamp <= #value# 
]]> 
</delete> 
```
推荐使用第一种方式，写为< 和 > (XML不对CDATA里的内容进行解析，因此如果CDATA中含有dynamic标签，将不起作用)

(9)include和sql标签
将常用的sql语句整理在一起，便于共用：
Xml代码

<sql id="selectBasicSql">

select

samplingTimestamp,onlineNum,year,

month,week,day,hour

from

OnlineMemberNum

</sql>

<sql id="whereSqlBefore">

where samplingTimestamp <= #samplingTimestamp#

</sql>

<select id="com.fashionfree.accesslog.selectOnlineMemberNumsBeforeSamplingTimestamp" parameterClass="hashmap" resultClass="OnlineMemberNum">

<include refid="selectBasicSql" />

<include refid="whereSqlBefore" />

</select>
```
<sql id="selectBasicSql"> 
select 
samplingTimestamp,onlineNum,year, 
month,week,day,hour 
from 
OnlineMemberNum 
</sql> 
<sql id="whereSqlBefore"> 
where samplingTimestamp &lt;= #samplingTimestamp# 
</sql> 
<select id="com.fashionfree.accesslog.selectOnlineMemberNumsBeforeSamplingTimestamp" parameterClass="hashmap" resultClass="OnlineMemberNum"> 
<include refid="selectBasicSql" /> 
<include refid="whereSqlBefore" /> 
</select> 
```
注意：sql标签只能用于被引用，不能当作mapped statement。如上例中有名为selectBasicSql的sql元素，试图使用其作为sql语句执行是错误的:
sqlMapClient.queryForList(“selectBasicSql”); ×

(10)随机选取记录
Xml代码

<sql id=”randomSql”>

ORDER BY rand() LIMIT #number#

</sql>
```
<sql id=”randomSql”> 
ORDER BY rand() LIMIT #number# 
</sql> 
```
从数据库中随机选取number条记录（只适用于MySQL）

(11)将SQL GROUP BY分组中的字段拼接
Xml代码

<sql id=”selectGroupBy>

SELECT

a.answererCategoryId, a.answererId, a.answererName,

a.questionCategoryId, a.score, a.answeredNum,

a.correctNum, a.answerSeconds, a.createdTimestamp,

a.lastQuestionApprovedTimestamp, a.lastModified, GROUP_CONCAT(q.categoryName) as categoryName

FROM

AnswererCategory a, QuestionCategory q

WHERE a.questionCategoryId = q.questionCategoryId

GROUP BY a.answererId

ORDER BY a.answererCategoryId

</sql>
```
<sql id=”selectGroupBy> 
SELECT 
a.answererCategoryId, a.answererId, a.answererName, 
a.questionCategoryId, a.score, a.answeredNum, 
a.correctNum, a.answerSeconds, a.createdTimestamp, 
a.lastQuestionApprovedTimestamp, a.lastModified, GROUP_CONCAT(q.categoryName) as categoryName 
FROM 
AnswererCategory a, QuestionCategory q 
WHERE a.questionCategoryId = q.questionCategoryId 
GROUP BY a.answererId 
ORDER BY a.answererCategoryId 
</sql>
```
注：SQL中使用了MySQL的GROUP_CONCAT函数

(12) 按照IN里面的顺序进行排序

①MySQL:
Xml代码

<sql id=”groupByInArea”>

select

moduleId, moduleName,

status, lastModifierId, lastModifiedName,

lastModified

from

StatModule

where

moduleId in (3, 5, 1)

order by

instr(',3,5,1,' , ','+ltrim(moduleId)+',')

</sql>
```
<sql id=”groupByInArea”> 
select 
moduleId, moduleName, 
status, lastModifierId, lastModifiedName, 
lastModified 
from 
StatModule 
where 
moduleId in (3, 5, 1) 
order by 
instr(',3,5,1,' , ','+ltrim(moduleId)+',') 
</sql> 
```
②SQLSERVER:
Xml代码

<sql id=”groupByInArea”>

select

moduleId, moduleName,

status, lastModifierId, lastModifiedName,

lastModified

from

StatModule

where

moduleId in (3, 5, 1)

order by

charindex(','+ltrim(moduleId)+',' , ',3,5,1,')

</sql>
```
<sql id=”groupByInArea”> 
select 
moduleId, moduleName, 
status, lastModifierId, lastModifiedName, 
lastModified 
from 
StatModule 
where 
moduleId in (3, 5, 1) 
order by 
charindex(','+ltrim(moduleId)+',' , ',3,5,1,') 
</sql>
```
    说明：查询结果将按照moduleId在in列表中的顺序(3, 5, 1)来返回
    MySQL : instr(str, substr)
    SQLSERVER: charindex(substr, str)
    返回字符串str 中子字符串的第一个出现位置
    ltrim(str)
    返回字符串str, 其引导(左面的)空格字符被删除

(13) resultMap
    resultMap负责将SQL查询结果集的列值映射成Java Bean的属性值。
Xml代码

<resultMap class="java.util.HashMap" id="getActionIdAndActionNumber">

<result column="actionId" property="actionId" jdbcType="BIGINT" javaType="long"/>

<result column="count" property="count" jdbcType="INT" javaType="int"/>

</resultMap>
```
<resultMap class="java.util.HashMap" id="getActionIdAndActionNumber"> 
<result column="actionId" property="actionId" jdbcType="BIGINT" javaType="long"/> 
<result column="count" property="count" jdbcType="INT" javaType="int"/> 
</resultMap> 
```
使用resultMap称为显式结果映射，与之对应的是resultClass(内联结果映射)，使用resultClass的最大好处便是简单、方便，不需显示指定结果，由iBATIS根据反射来确定自行决定。而resultMap则可以通过指定jdbcType和javaType，提供更严格的配置认证。

(14) typeAlias
Xml代码

<typeAlias alias="MemberOnlineDuration" type="com.fashionfree.stat.accesslog.model.MemberOnlineDuration" />

<typeAlias>允许你定义别名，避免重复输入过长的名字。
```
<typeAlias alias="MemberOnlineDuration" type="com.fashionfree.stat.accesslog.model.MemberOnlineDuration" /> 
<typeAlias>允许你定义别名，避免重复输入过长的名字。
```
(15) remap
Xml代码

<select id="testForRemap" parameterClass="hashMap" resultClass="hashMap" remapResults="true">

select

userId

<isEqual property="tag" compareValue="1">

, userName

</isEqual>

<isEqual property="tag" compareValue="2">

, userPassword

</isEqual>

from

UserInfo

</select>
```
<select id="testForRemap" parameterClass="hashMap" resultClass="hashMap" remapResults="true"> 
select 
userId 
<isEqual property="tag" compareValue="1"> 
, userName 
</isEqual> 
<isEqual property="tag" compareValue="2"> 
, userPassword 
</isEqual> 
from 
UserInfo 
</select> 
```
此例中，根据参数tag值的不同，会获得不同的结果集，如果没有remapResults="true"属性，iBatis会将第一次查询时的结果集缓存，下次再执行时（必须还是该进程中）不会再执行结果集映射，而是会使用缓存的结果集。
因此，如果上面的例子中remapResult为默认的false属性，而有一段程序这样书写：
Java代码

HashMap<String, Integer> hashMap = new HashMap<String, Integer>();

hashMap.put("tag", 1);

sqlClient.queryForList("testForRemap", hashMap);

hashMap.put("tag", 2);

sqlClient.queryForList("testForRemap", hashMap);
```
HashMap<String, Integer> hashMap = new HashMap<String, Integer>(); 
hashMap.put("tag", 1); 
sqlClient.queryForList("testForRemap", hashMap); 
hashMap.put("tag", 2); 
sqlClient.queryForList("testForRemap", hashMap); 
```
则程序会在执行最后一句的query查询时报错，原因就是iBATIS使用了第一次查询时的结果集，而前后两次的结果集是不同的:(userId, userName)和(userId, userPassword)，所以导致出错。如果使用了remapResults="true"这一属性，iBATIS会在每次执行查询时都执行结果集映射，从而避免错误的发生（此时会有较大的开销）。

(16) dynamic标签的prepend

dynamic标签的prepend属性作为前缀添加到结果内容前面，当标签的结果内容为空时，prepend属性将不起作用。
当dynamic标签中存在prepend属性时，将会把其嵌套子标签的第一个prepend属性忽略。例如：
Xml代码

<sql id="whereSql">

<dynamic prepend="where ">

<isNotNull property="userId" prepend="BOGUS">

userId = #userId#

</isNotNull>

<isNotEmpty property="userName" prepend="and ">

userName = #userName#

</isNotEmpty>

</dynamic>

</sql>
```
<sql id="whereSql"> 
<dynamic prepend="where "> 
<isNotNull property="userId" prepend="BOGUS"> 
userId = #userId# 
</isNotNull> 
<isNotEmpty property="userName" prepend="and "> 
userName = #userName# 
</isNotEmpty> 
</dynamic> 
</sql>
```
此例中，dynamic标签中含有两个子标签<isNotNull>和<isNotEmpty>。根据前面叙述的原则，如果<isNotNull>标签中没有prepend="BOGUS" 这一假的属性来让dynamic去掉的话，<isNotEmpty>标签中的and就会被忽略，会造成sql语法错误。
注意：当dynamic标签没有prepend属性时，不会自动忽略其子标签的第一个prepend属性。
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原文地址：https://www.cnblogs.com/sayou/p/4763237.html