为什么我的 ORDER BY create_time ASC 变成了 order by ASC
作者：LigaAI
- 2022 年 2 月 28 日
本文字数：11936 字
阅读完需：约 39 分钟
开发是一件“升级打怪”的事，在开发各个环境下，妖怪频出，战术不断升级。 程序员想要抛开迷雾，窥得真相，须得先参透个中招式，然后逐一解决。
本期文章的内容“就地取材”，来源自 LigaAI 工作中常见的开发问题，并通过「场景测试—分析区别—提出解决方案」的方法帮我们规避和尽早识别这种陷阱~话不多说，一起来康康吧！
遇到的问题：两条一毛一样的 sql，分页的 sql 执行没问题，不分页的 sql 执行就有问题？
01、 场景准备
>> 测试场景
CREATE TABLE `test_page_or_not` ( `id` bigint(20) NOT NULL COMMENT '主键编号', `name` varchar(255) COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '名称', `create_time` datetime(3) NOT NULL COMMENT '创建时间', `create_by` bigint(20) NOT NULL COMMENT '创建人', PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci COMMENT='测试分页与不分页';
INSERT INTO `test_page_or_not` (`id`, `name`, `create_time`, `create_by`) VALUES (1, 'name1', '2022-02-17 22:25:04.000', 0);INSERT INTO `test_page_or_not` (`id`, `name`, `create_time`, `create_by`) VALUES (2, 'name2', '2022-02-17 22:25:04.000', 0);INSERT INTO `test_page_or_not` (`id`, `name`, `create_time`, `create_by`) VALUES (3, 'name3', '2022-02-18 22:25:04.000', 0);INSERT INTO `test_page_or_not` (`id`, `name`, `create_time`, `create_by`) VALUES (4, 'name4', '2022-02-19 22:25:04.000', 0);
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一些 Java 类文件：
public class TestWithPageDTO extends PageDTO {
private static final long serialVersionUID = -970059691509424681L;
private String name;
private String orderBy;
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public String getOrderBy() { return orderBy; }
public void setOrderBy(String orderBy) { this.orderBy = orderBy; }
@Override public String toString() { return "TestWithPageDTO{" + "name='" + name + '\'' + ", orderBy='" + orderBy + '\'' + '}'; }}
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public class PageDTO extends BaseDTO {
private static final long serialVersionUID = 2572899663737669356L;
private Integer pageSize = 10;
private Integer pageNum = 1;
public Integer getPageSize() { return pageSize; }
public void setPageSize(Integer pageSize) { this.pageSize = pageSize; }
public Integer getPageNum() { return pageNum; }
public void setPageNum(Integer pageNum) { this.pageNum = pageNum; }
@Override public String toString() { return "PageDTO{" + "pageSize=" + pageSize + ", pageNum=" + pageNum + '}'; }}
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public class BaseDTO implements Serializable {
private static final long serialVersionUID = 9055050419546393543L;}
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public class TestWithoutPageDTO extends BaseDTO {
private static final long serialVersionUID = 7862152821778815456L;
private String name;
private String orderBy;
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public String getOrderBy() { return orderBy; }
public void setOrderBy(String orderBy) { this.orderBy = orderBy; }
@Override public String toString() { return "TestWithoutPageDTO{" + "name='" + name + '\'' + ", orderBy='" + orderBy + '\'' + '}'; }}
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>> 分页场景
先来看看分页场景的参数、代码和日志打印，从日志可以看出 SQL 的最后执行是没有问题的。请求参数：
{ "name": "name", "orderBy": "ASC"}
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sql 文件：
<!--分页查询数据--><select id="selectWithPage" parameterType="com.peng.java_study.api.dto.TestWithPageDTO" resultMap="BaseResultMap"> SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", #{name, jdbcType=VARCHAR}, "%") <if test="orderBy != null and orderBy != ''"> ORDER BY tpon.create_time ${orderBy} </if></select>
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日志：
2022-02-18 16:39:09.217 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage_COUNT : ==> Preparing: SELECT count(0) FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", ?, "%")2022-02-18 16:39:09.218 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage_COUNT : ==> Parameters: name(String)2022-02-18 16:39:09.234 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage_COUNT : <== Total: 12022-02-18 16:39:09.236 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage : ==> Preparing: SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", ?, "%") ORDER BY tpon.create_time ASC LIMIT ?2022-02-18 16:39:09.236 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage : ==> Parameters: name(String), 10(Integer)2022-02-18 16:39:09.238 DEBUG 18036 --- [nio-8080-exec-3] c.p.j.c.m.T.selectWithPage : <== Total: 4
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>> 不分页场景
再来看看正常场景的参数、代码和日志打印：从日志可以看出 SQL 的执行报错了，因为 SQL 从 ORDER BY tpon.create_time ASC 变成了 order by ASC。请求参数：
{ "name": "name", "orderBy": "ASC"}
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sql 文件：
<!--不分页查询数据--><select id="selectWithoutPage" parameterType="com.peng.java_study.api.dto.TestWithoutPageDTO" resultMap="BaseResultMap"> SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", #{name, jdbcType=VARCHAR}, "%") <if test="orderBy != null and orderBy != ''"> ORDER BY tpon.create_time ${orderBy} </if></select>
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日志:
2022-02-18 16:52:24.684 DEBUG 18036 --- [nio-8080-exec-5] c.p.j.c.m.T.selectWithoutPage : ==> Preparing: SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", ?, "%") order by ASC2022-02-18 16:52:24.684 DEBUG 18036 --- [nio-8080-exec-5] c.p.j.c.m.T.selectWithoutPage : ==> Parameters: name(String)2022-02-18 16:52:24.687 ERROR 18036 --- [nio-8080-exec-5] c.p.java_study.rest.test.TestController : TestController.list(TestWithoutPageDTO) exception:
org.springframework.jdbc.BadSqlGrammarException: ### Error querying database. Cause: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ASC' at line 1### The error may exist in file [D:\file\project\1\java-study\java-study-provider\target\classes\mapper\TestPageOrNotMapper.xml]### The error may involve com.peng.java_study.core.mapper.TestPageOrNotMapper.selectWithoutPage-Inline### The error occurred while setting parameters### SQL: SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", ?, "%") order by ASC### Cause: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ASC' at line 1; bad SQL grammar []; nested exception is java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ASC' at line 1 at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:235) ~[spring-jdbc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72) ~[spring-jdbc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:91) ~[mybatis-spring-2.0.6.jar:2.0.6] at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:441) ~[mybatis-spring-2.0.6.jar:2.0.6] at com.sun.proxy.$Proxy92.selectList(Unknown Source) ~[na:na] at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:224) ~[mybatis-spring-2.0.6.jar:2.0.6] at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:147) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:80) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.binding.MapperProxy$PlainMethodInvoker.invoke(MapperProxy.java:152) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:85) ~[mybatis-3.5.6.jar:3.5.6] at com.sun.proxy.$Proxy93.selectWithoutPage(Unknown Source) ~[na:na] at com.peng.java_study.core.manager.impl.TestPageOrNotManagerImpl.selectWithoutPage(TestPageOrNotManagerImpl.java:36) ~[classes/:na] at com.peng.java_study.rest.test.TestController.list(TestController.java:150) ~[classes/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at com.peng.java_study.config.LanguageFilter.doFilter(LanguageFilter.java:39) ~[classes/:na] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.31.jar:9.0.31] at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]Caused by: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ASC' at line 1 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.ClientPreparedStatement.execute(ClientPreparedStatement.java:370) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.zaxxer.hikari.pool.ProxyPreparedStatement.execute(ProxyPreparedStatement.java:44) ~[HikariCP-3.4.2.jar:na] at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.execute(HikariProxyPreparedStatement.java) ~[HikariCP-3.4.2.jar:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:59) ~[mybatis-3.5.6.jar:3.5.6] at com.sun.proxy.$Proxy132.execute(Unknown Source) ~[na:na] at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:64) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) ~[mybatis-3.5.6.jar:3.5.6] at com.github.pagehelper.util.ExecutorUtil.pageQuery(ExecutorUtil.java:177) ~[pagehelper-5.1.11.jar:na] at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:104) ~[pagehelper-5.1.11.jar:na] at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61) ~[mybatis-3.5.6.jar:3.5.6] at com.sun.proxy.$Proxy130.query(Unknown Source) ~[na:na] at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147) ~[mybatis-3.5.6.jar:3.5.6] at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140) ~[mybatis-3.5.6.jar:3.5.6] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:427) ~[mybatis-spring-2.0.6.jar:2.0.6] ... 62 common frames omitted
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02、分析
两个 sql 的语句和入参是一毛一样的，唯一的区别在于一个使用了分页，另一个没有使用分页。因此我们来仔细分析下报错日志，查找 sql 被修改的原因。
>> 分析具体的代码调用链
在日志的 99 行，我们发现有一个 PageHelper 的调用栈。
at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:104) ~[pagehelper-5.1.11.jar:na]
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进入该行代码，发现它进入了分页查询。问题来了：
明明我们使用的对象是 TestWithoutPageDTO.class，调用的 sql 也是 selectWithoutPage，为啥还是会进入分页查询呢？让我们来一探究竟：
下图的 1 号红色圈可以帮助我们判断当前 sql 是否需要进行分页。根据图数据显示，本应该走 else 的分支（不分页，3 号绿色圈）的，但最后进了 if 分支（分页，2 号红色圈）。
继续使用 skip 方法查看。按照该代码的逻辑，4 号红色圈的 page 应为 null 才不会分页；既然分页了，那就说明 page 不为 null 。
利用 getPage 方法，在经过调试后我们发现，代码进入了 5 号红色圈位置。这表明，要么，参数对象已实现了 IPage 接口，要么，supportMethodsArguments 参数为 true。
根据上面 sql 参数，我们得知参数是 TestWithoutPageDTO.class 的实例，它的类继承图如下。该类并没有继承或实现 IPage 接口，因此肯定是 supportMethodsArguments 参数为 true 。
进入 PageHelper 官网，查看 supportMethodsArguments 参数介绍：根据参数对象中的属性自动识别是否需要分页。
再查看当前项目的配置，发现当前项目确实配置了该参数，既然它确实可以简化一些操作，那这个属性还不能改动。
supportMethodsArguments：支持通过 Mapper 接口参数来传递分页参数，默认值false，分页插件会从查询方法的参数值中，自动根据上面 params 配置的字段中取值，查找到合适的值时就会自动分页。使用方法可以参考测试代码中的 com.github.pagehelper.test.basic 包下的 ArgumentsMapTest 和 ArgumentsObjTest。复制代码
pagehelper: helperDialect: mysql reasonable: true supportMethodsArguments: true params: count=countSql 复制代码
继续进入 5 号红色圈内部的 getPageFromObject 方法，重点看一下 13 号黄色圈，这个圈使用反射的方式去获取参数对象的 orderBy 属性。
很快，问题找到了：
笔者为了排序在实体中增加了 orderBy 属性，因此 hasOrderBy 为 true；进入 9 号红色圈的代码块后，创建了分页的对象，导致 PageHelper 插件把该 sql 语句作为分页查询来对待，自然也就把 ORDER BY create_time ASC 语句偷梁换柱了。
找出问题所在，接下来就是解决了。
03、解决
>> 方案一：
将 supportMethodsArguments 属性改为 false ，但这个改动很有可能会对现有的 sql 查询语句造成一定的影响，因此不推荐。
pagehelper: helperDialect: mysql reasonable: true supportMethodsArguments: false params: count=countSql 复制代码
>> 方案二：
将实体类中的 orderBy 改为另一个变量名，比如 orderByCreateTime ，这样就可以避免 PageHelper 认错分页参数了。
public class TestWithoutPageDTO extends BaseDTO {
private static final long serialVersionUID = 7862152821778815456L;
private String name;
private String orderByCreateTime;
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public String getOrderByCreateTime() { return orderByCreateTime; }
public void setOrderByCreateTime(String orderByCreateTime) { this.orderByCreateTime = orderByCreateTime; }
@Override public String toString() { return "TestWithoutPageDTO{" + "name='" + name + '\'' + ", orderByCreateTime='" + orderByCreateTime + '\'' + '}'; }}
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<!--不分页查询数据--><select id="selectWithoutPage" parameterType="com.peng.java_study.api.dto.TestWithoutPageDTO" resultMap="BaseResultMap"> SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", #{name, jdbcType=VARCHAR}, "%") <if test="orderByCreateTime != null and orderByCreateTime != ''"> ORDER BY tpon.create_time ${orderByCreateTime} </if></select>
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修改后的日志，无异常产生：
2022-02-18 21:00:58.928 DEBUG 9768 --- [nio-8080-exec-1] c.p.j.c.m.T.selectWithoutPage : ==> Preparing: SELECT * FROM test_page_or_not tpon WHERE tpon.name LIKE CONCAT("%", ?, "%") ORDER BY tpon.create_time ASC2022-02-18 21:00:58.944 DEBUG 9768 --- [nio-8080-exec-1] c.p.j.c.m.T.selectWithoutPage : ==> Parameters: name(String)2022-02-18 21:00:58.960 DEBUG 9768 --- [nio-8080-exec-1] c.p.j.c.m.T.selectWithoutPage
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本文作者：rookie0peng
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