Java Mybatis：选择注释中的“小于”问题
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Mybatis : "less than" issue in Select annotations
提问by Om.
I am using java7, spring 3 and mybatis
我正在使用 java7、spring 3 和 mybatis
Pom.xml
xml文件
<org.mybatis-version>3.2.8</org.mybatis-version>
<org.mybatis-spring-version>1.2.2</org.mybatis-spring-version>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>${org.mybatis-version}</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>${org.mybatis-spring-version}</version>
</dependency>
While using annotation based Select i came across with strange issue where below mentioned code was throwing exception due to use of < (Less then) while > (greater then) works as expected.
在使用基于注释的 Select 时，我遇到了一个奇怪的问题，下面提到的代码由于使用 < (Less then) 而抛出异常 > (greater then) 按预期工作。
<script>
SELECT * FROM STUDENT
WHERE DEPARTMENT_ID = #{depId}
<if test='joiningDate != null'> AND STUDENT_ID <= #{joiningDate} </if>
</script>
After googling for a while i find out this issue reported below.
谷歌搜索一段时间后，我发现这个问题报告如下。
https://code.google.com/p/mybatis/issues/detail?id=787
https://code.google.com/p/mybatis/issues/detail?id=787
Above issue can be fixed by replacing < (less then) with <as shown below.
可以通过将 < (less then) 替换<为如下所示来解决上述问题。
<script>
SELECT * FROM STUDENT
WHERE DEPARTMENT_ID = #{depId}
<if test='joiningDate != null'> AND STUDENT_ID <= #{joiningDate} </if>
</script>
I have also came across of suggestion for using using CDATA or ^ in respected scenarios which i haven't given try yet.
我还遇到了在我尚未尝试的受人尊敬的场景中使用 CDATA 或 ^ 的建议。
Question:
题：
- My question is shouldn't this issue be fixed by Mybatis team (at-least xml specific conversion for frequently used query tags) or this behaviour is as expected since we are using
<script>tag ?? - Is there any alternate solution which i have missed out ?
- 我的问题是这个问题不应该由 Mybatis 团队解决（至少对常用查询标签进行 xml 特定转换），或者这种行为是否符合预期，因为我们正在使用
<script>标签？ - 有没有我错过的替代解决方案？
采纳答案by Landys
To be fair, it's not the issue in MyBatis, but the behaviour of XML parsing.
公平地说，这不是 中的问题MyBatis，而是 XML 解析的行为。
If you don't want characters such as <and &to be parsed, you can use the term CDATAto prevent the XML parser to parse such text. Please refer to http://www.w3schools.com/xml/xml_cdata.aspfor detail. Or you may escape it with <as comments.
如果您不想解析诸如<和 之类的字符&，则可以使用该术语CDATA来阻止 XML 解析器解析此类文本。详情请参考http://www.w3schools.com/xml/xml_cdata.asp。或者你可以用<注释来逃避它。
I.E.
IE
<script>
SELECT * FROM STUDENT
WHERE DEPARTMENT_ID = #{depId}
<if test='joiningDate != null'>
<![CDATA[
AND STUDENT_ID <= #{joiningDate}
]]>
</if>
</script>
回答by Abrahan Gonzalez
you too can use that.
你也可以使用它。
<= less or equal SELECT * FROM STUDENT WHERE DEPARTMENT_ID = #{depId}
<= 小于或等于 SELECT * FROM STUDENT WHERE DEPARTMENT_ID = #{depId}
= greater that
= 大于
<script>
SELECT * FROM STUDENT
WHERE DEPARTMENT_ID = #{depId}
<if test='joiningDate != null'>
<![CDATA[
AND STUDENT_ID >= #{joiningDate}
]]>
</if>
</script>
