MySQL的别名为select语句失败，列未找到(MySQL select statement wi

开发环境参考：

Fedora FC18
Tomcat Server 7.0.39 (localhost config)
Eclipse Juno Release 2
Mysql-connecor-java Ver. 5.1.26 (jar)
Mysql-server Ver. 5.5.32 (jar)

下面的SELECT语句失败，“列‘深度’未找到”：

"select node.subEntityID, node.lft, node.rgt, (count(parent.subEntityID) - 1) as depth
 from ENTITY as node, ENTITY as parent
 where node.lft between parent.lft and parent.rgt
 group by node.subEntityID order by node.lft";

这个SELECT语句成功使用命令级别的MySQL作为

use dbName;
select node.subEntityID, node.lft, node.rgt, (count(parent.subEntityID) - 1) as depth
  from ENTITY as node, ENTITY as parent
  where node.lft between parent.lft and parent.rgt
  group by node.subEntityID order by node.lft;

使用MySQL工作台的SQL查询时版本的select语句也成功。 5.2.4.7。

相关的Java代码片段下面给出：

rs = stmt.executeQuery(typeEntityList);
// The depth alias does not print out in this for loop
for (int i=1; i<rs.getMetaData().getColumnCount()+1; i++) {
    System.out.println(rs.getMetaData().getColumnName(i));
    System.out.println(rs.getMetaData().getColumnLabel(i));
}
while (rs.next()) {
    // "depth" fails at the following statement
    System.out.println("depth: " + rs.getInt("depth"));
    String s = rs.getString("lft") + "  "
        + rs.getString("subEntityID") + "  "
        + rs.getString("rgt");
    System.out.println(s);
    entityList.add(s);
}

另外，我在谷歌搜索的是MySQL的别名行为在最新版本的改变中。一个建议的修复是追加"?useOldAliasMetadataBehavior=true"到MySQL连接字符串恢复到原来的行为，但这并没有解决这个问题。

这里的堆栈跟踪：

值java.sql.SQLException：列“深度”没有找到。在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:1078）在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:989）在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:975 ）在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:920）在com.mysql.jdbc.ResultSetImpl.findColumn（ResultSetImpl.java:1167）在com.mysql.jdbc.ResultSetImpl.getString（ResultSetImpl.java： 5733）在EntityAssessmentEntityActions.EntityAssessmentEntityListAction.detailedEntityList（EntityAssessmentEntityListAction.java:184）在EntityAssessmentEntityActions.EntityAssessmentEntityListAction.execute（EntityAssessmentEntityListAction.java:69）在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）在sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl的.java：57）在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:606）在com.opensymphony.xwork2.DefaultActionInvocation.invokeAction（DefaultActi onInvocation.java:450）在com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly（DefaultActionInvocation.java:289）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:252）在org.apache.struts2.interceptor.debugging .DebuggingInterceptor.intercept（DebuggingInterceptor.java:256）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept（DefaultWorkflowInterceptor.java:176）在融为一体。 opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept（MethodFilterInterceptor.java:98）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept（ValidationInterceptor.java： 265）在org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept（AnnotationValidationInterceptor.java:68）在com.opensymphony.xwork2.interceptor。 MethodFilterInterceptor.intercept（MethodFilterInterceptor.java:98）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept（ConversionErrorInterceptor.java:138）在com.opensymphony .xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept（ParametersInterceptor.java:249）在com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept（MethodFilterInterceptor.java:98 ）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept（ParametersInterceptor.java:249）在com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept（ MethodFilterInterceptor.java:98）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.int erceptor.StaticParametersInterceptor.intercept（StaticParametersInterceptor.java:191）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在org.apache.struts2.interceptor.MultiselectInterceptor.intercept（MultiselectInterceptor.java:73）在COM .opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在org.apache.struts2.interceptor.CheckboxInterceptor.intercept（CheckboxInterceptor.java:91）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246 ）在org.apache.struts2.interceptor.FileUploadInterceptor.intercept（FileUploadInterceptor.java:252）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept（ ModelDrivenInterceptor.java:100）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ScopedModelDrivenInte rceptor.intercept（ScopedModelDrivenInterceptor.java:141）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept（ChainingInterceptor.java:145）在com.opensymphony .xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept（PrepareInterceptor.java:171）在com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept（MethodFilterInterceptor.java:98 ）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept（I18nInterceptor.java:176）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation。的java：246）在org.apache.struts2.interceptor.ServletConfigInterceptor.intercept（ServletConfigInterceptor.java:164）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvoc ation.java:246）在com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept（AliasInterceptor.java:193）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在com.opensymphony.xwork2.interceptor .ExceptionMappingInterceptor.intercept（ExceptionMappingInterceptor.java:187）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:246）在org.apache.struts2.impl.StrutsActionProxy.execute（StrutsActionProxy.java:54）在有机apache.struts2.dispatcher.Dispatcher.serviceAction（Dispatcher.java:546）在org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction（ExecuteOperations.java:77）在org.apache.struts2.dispatcher.ng.filter。 StrutsPrepareAndExecuteFilter.doFilter（StrutsPrepareAndExecuteFilter.java:91）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:243）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在组织.apache.catalina。 core.StandardWrapperValve.invoke（StandardWrapperValve.java:222）在org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:123）在org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:472）在org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:171）在org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:99）在org.apache.catalina.valves.AccessLogValve.invoke （AccessLogValve.java:947）在org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:118）在org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:408）在org.apache。 coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1009）在org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:589）在org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run（ JIoEndpoint.java:312）在java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:11 45）在java.util.concurrent.ThreadPoolExecutor中的$ Worker.run（ThreadPoolExecutor.java:615）在java.lang.Thread.run（Thread.java:724）

Answer 1:

那么StackOverflow的会员，我发现这个问题，但现在我从拉我的头发所有这些秃小时。

基于Eclipse的Juno，有Java源代码的选择为“Organnize进口”。“所以，当我有一个未定义的变量，我用这个方便的选项来清理进口。Eclipse的朱诺进口mysql的连接器，” java.sql中。连接”，而不是‘com.mysql.jdbc.connection’连接器。我改变了Java源代码的进口，现在我好与这个servlet前进，但没有经过我出去找一些柔沛或落健还是？......罗伊W.

Answer 2:

我遇到类似的问题在我的项目（我使用Eclipse月神）。

我克服它的方式，是将MysqlDataSource设置为setUseOldAliasMetadataBehavior（真）;