[ http://issues.apache.org/jira/browse/DERBY-2014?page=comments#action_12445862 ] Yip Ng commented on DERBY-2014: -------------------------------
Thanks Manish and Bernt for reviewing the patch. Bernt: Good question. If I am not mistaken, the isEquivalent() method is used to compare the select column against the group by with expression. Note that it is comparing the structural form of the two expressions for equivalence at bind phase and not comparing the actual row values at runtime to produce a result. Thus, I believe in this context, it is valid. Manish: I'll see if I can find some time to convert the testcases in the patch to JUnit testcases. Thanks for the suggestion. > NullPointerException with NULLIF in GROUP BY clause > --------------------------------------------------- > > Key: DERBY-2014 > URL: http://issues.apache.org/jira/browse/DERBY-2014 > Project: Derby > Issue Type: Bug > Components: SQL > Affects Versions: 10.2.1.6, 10.3.0.0 > Environment: Any > Reporter: Yip Ng > Assigned To: Yip Ng > Attachments: derby2014-trunk-diff01.txt, derby2014-trunk-stat01.txt > > > A NPE occurs when NULLIF is used in the GROUP BY clause. > ij> create table t1 (c1 int); > 0 rows inserted/updated/deleted > ij> insert into t1 values 1,2,2,3; > 4 rows inserted/updated/deleted > ij> select nullif(c1,c1) from t1 group by nullif(c1,c1); > ERROR XJ001: Java exception: ': java.lang.NullPointerException'. > Stacktrace: > java.lang.NullPointerException > at > org.apache.derby.impl.sql.compile.ConstantNode.isEquivalent(ConstantNode.java:285) > at > org.apache.derby.impl.sql.compile.CastNode.isEquivalent(CastNode.java:1044) > at > org.apache.derby.impl.sql.compile.ConditionalNode.isEquivalent(ConditionalNode.java:518) > at > org.apache.derby.impl.sql.compile.GroupByList.findGroupingColumn(GroupByList.java:244) > at > org.apache.derby.impl.sql.compile.VerifyAggregateExpressionsVisitor.skipChildren(VerifyAggregateExpressionsVisitor.java:146) > at > org.apache.derby.impl.sql.compile.ConditionalNode.accept(ConditionalNode.java:484) > at > org.apache.derby.impl.sql.compile.ResultColumn.accept(ResultColumn.java:1515) > at > org.apache.derby.impl.sql.compile.QueryTreeNodeVector.accept(QueryTreeNodeVector.java:159) > at > org.apache.derby.impl.sql.compile.SelectNode.bindExpressions(SelectNode.java:619) > at > org.apache.derby.impl.sql.compile.FromSubquery.bindExpressions(FromSubquery.java:262) > at > org.apache.derby.impl.sql.compile.FromList.bindExpressions(FromList.java:337) > at > org.apache.derby.impl.sql.compile.SelectNode.bindExpressions(SelectNode.java:500) > at > org.apache.derby.impl.sql.compile.DMLStatementNode.bindExpressions(DMLStatementNode.java:249) > at > org.apache.derby.impl.sql.compile.DMLStatementNode.bind(DMLStatementNode.java:162) > at > org.apache.derby.impl.sql.compile.CursorNode.bind(CursorNode.java:253) > at > org.apache.derby.impl.sql.GenericStatement.prepMinion(GenericStatement.java:345) > at > org.apache.derby.impl.sql.GenericStatement.prepare(GenericStatement.java:119) > at > org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(GenericLanguageConnectionContext.java:745) > at > org.apache.derby.impl.jdbc.EmbedStatement.execute(EmbedStatement.java:568) > at > org.apache.derby.impl.jdbc.EmbedStatement.execute(EmbedStatement.java:517) > at org.apache.derby.impl.tools.ij.ij.executeImmediate(ij.java:321) > at org.apache.derby.impl.tools.ij.utilMain.doCatch(utilMain.java:517) > at > org.apache.derby.impl.tools.ij.utilMain.runScriptGuts(utilMain.java:370) > at org.apache.derby.impl.tools.ij.utilMain.go(utilMain.java:268) > at org.apache.derby.impl.tools.ij.Main.go(Main.java:204) > at org.apache.derby.impl.tools.ij.Main.mainCore(Main.java:170) > at org.apache.derby.impl.tools.ij.Main14.main(Main14.java:56) > at org.apache.derby.tools.ij.main(ij.java:71) > sysinfo: > ------------------ Java Information ------------------ > Java Version: 1.4.2_12 > Java Vendor: Sun Microsystems Inc. > Java home: C:\jdk142\jre > Java classpath: classes;. > OS name: Windows XP > OS architecture: x86 > OS version: 5.1 > Java user name: yip > Java user home: C:\Documents and Settings\Administrator > Java user dir: C:\derby\trunk > java.specification.name: Java Platform API Specification > java.specification.version: 1.4 > --------- Derby Information -------- > JRE - JDBC: J2SE 1.4.2 - JDBC 3.0 > [C:\derby\trunk\classes] 10.3.0.0 alpha - (1) > ------------------------------------------------------ > ----------------- Locale Information ----------------- > Current Locale : [English/United States [en_US]] > Found support for locale: [de_DE] > version: 10.3.0.0 alpha - (1) > Found support for locale: [es] > version: 10.3.0.0 alpha - (1) > Found support for locale: [fr] > version: 10.3.0.0 alpha - (1) > Found support for locale: [it] > version: 10.3.0.0 alpha - (1) > Found support for locale: [ja_JP] > version: 10.3.0.0 alpha - (1) > Found support for locale: [ko_KR] > version: 10.3.0.0 alpha - (1) > Found support for locale: [pt_BR] > version: 10.3.0.0 alpha - (1) > Found support for locale: [zh_CN] > version: 10.3.0.0 alpha - (1) > Found support for locale: [zh_TW] > version: 10.3.0.0 alpha - (1) > ------------------------------------------------------ -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
