新規にテーブルを作成した後、テーブルに項目を付け忘れたので、
追加したのですが、[作成]ボタンを押したあとに、エラーになってしまいました。

エラー後は、閲覧もできない（同じエラー画面になる）状態となります。
＃Tomcatを再起動すると使えるようになりますが、変更は反映されていないようです。

解決策がありましたらご教授いただけませんでしょうか？

■環境
・Tomcat5
・JDK1.4.2_12
・WindowsXP Pro

■作成したテーブル
テーブル名：テスト
───┬────┬────┬──────
表示名│タイプ │必須 │オプション
───┼────┼────┼──────
文字 │文字列 │ │通常の文字列
日付 │日付 │ │1 年前 から 1 年後 まで

■追加したい項目
───┬────┬────┬──────
表示名│タイプ │必須 │オプション
───┼────┼────┼──────
数値 │数値 │ │

■エラー画面

Tuigwaa 上でアプリケーションエラーが発生しました。
Tuigwaa 上でアプリケーションエラーが発生しました。 しばらくたってからアクセスして下さい.....
–

■スタックトレース(Tomcatのログ）
—
2006-08-29 18:20:24 StandardContext[/tuigwaa]Application Error Detected and Forwarded
org.seasar.framework.exception.SSQLException: [ESSR0072]SQLで例外(SQL=[alter table testsite.tgw_entity_ add column tgw_attr_1 date], ErrorCode=-58, SQLState=s0021)が発生しました
at org.seasar.extension.dbcp.impl.ConnectionWrapperImpl$PreparedStatementWrapper.wrapException(ConnectionWrapperImpl.java:555)
at org.seasar.extension.dbcp.impl.ConnectionWrapperImpl$PreparedStatementWrapper.wrapException(ConnectionWrapperImpl.java:550)
at org.seasar.extension.dbcp.impl.ConnectionWrapperImpl$PreparedStatementWrapper.executeUpdate(ConnectionWrapperImpl.java:574)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl.executeSQL(DynaDatabaseServiceImpl.java:181)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl.alterTable(DynaDatabaseServiceImpl.java:147)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac.alterTable$$invokeSuperMethod$$(DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac.java)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac$$MethodInvocation$$alterTable0.proceed(MethodInvocationClassGenerator.java)
at org.seasar.extension.tx.RequiredInterceptor.invoke(RequiredInterceptor.java:40)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac$$MethodInvocation$$alterTable0.proceed(MethodInvocationClassGenerator.java)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac.alterTable(DynaDatabaseServiceImpl$$EnhancedByS2AOP$$12943ac.java)
at org.seasar.tuigwaa.model.ModelServiceImpl.alterEntity(ModelServiceImpl.java:185)
at org.seasar.tuigwaa.controller.EntityAction.doSave(EntityAction.java:127)
at org.seasar.tuigwaa.util.ajax.AbstractRowSetAction.saveRowSet(AbstractRowSetAction.java:62)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
at org.apache.struts.actions.MappingDispatchAction.execute(MappingDispatchAction.java:169)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.seasar.struts.processor.S2TilesRequestProcessor.processActionPerform(S2TilesRequestProcessor.java:122)
at org.seasar.struts.processor.AcceptorImpl.process(AcceptorImpl.java:126)
at org.seasar.struts.processor.S2TilesRequestProcessor.process(S2TilesRequestProcessor.java:61)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.seasar.tuigwaa.util.filter.TgwFilter.doFilter(TgwFilter.java:67)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.seasar.tuigwaa.util.filter.EncodingFilter.doFilter(EncodingFilter.java:65)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.seasar.tuigwaa.util.filter.ForwardFilter.doFilter(ForwardFilter.java:83)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.seasar.struts.filter.S2StrutsFilter.doFilter(S2StrutsFilter.java:45)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.seasar.framework.container.filter.S2ContainerFilter.doFilter(S2ContainerFilter.java:60)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.sql.SQLException: Column constraints are not acceptable in statement [alter table testsite.tgw_entity_ add column tgw_attr_1 date]
at org.hsqldb.jdbc.Util.throwError(Unknown Source)
at org.hsqldb.jdbc.jdbcPreparedStatement.executeUpdate(Unknown Source)
at org.seasar.extension.dbcp.impl.ConnectionWrapperImpl$PreparedStatementWrapper.executeUpdate(ConnectionWrapperImpl.java:572)
... 66 more