From 9909f9ce722dfca240b49357329e2fd937763128 Mon Sep 17 00:00:00 2001 From: Steve Ebersole Date: Wed, 28 Oct 2009 15:49:36 +0000 Subject: [PATCH] HHH-3972 - Adding FETCH FIRST and OFFSET support to DerbyDialect git-svn-id: https://svn.jboss.org/repos/hibernate/core/trunk@17867 1b8cb986-b30d-0410-93ca-fae66ebed9b2 --- .../org/hibernate/dialect/DerbyDialect.java | 99 ++++++++++++++++++- .../dialect/DerbyDialectTestCase.java | 93 +++++++++++++++++ 2 files changed, 190 insertions(+), 2 deletions(-) create mode 100644 core/src/test/java/org/hibernate/dialect/DerbyDialectTestCase.java diff --git a/core/src/main/java/org/hibernate/dialect/DerbyDialect.java b/core/src/main/java/org/hibernate/dialect/DerbyDialect.java index 62b8c57c1c..c09b69cfe1 100755 --- a/core/src/main/java/org/hibernate/dialect/DerbyDialect.java +++ b/core/src/main/java/org/hibernate/dialect/DerbyDialect.java @@ -27,6 +27,7 @@ package org.hibernate.dialect; import org.hibernate.Hibernate; import org.hibernate.QueryException; import org.hibernate.HibernateException; +import org.hibernate.util.ReflectHelper; import org.hibernate.engine.Mapping; import org.hibernate.engine.SessionFactoryImplementor; import org.hibernate.type.Type; @@ -39,6 +40,10 @@ import org.hibernate.sql.DerbyCaseFragment; import java.util.List; import java.util.ArrayList; +import java.lang.reflect.Method; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; /** * Hibernate Dialect for Cloudscape 10 - aka Derby. This implements both an @@ -49,13 +54,39 @@ import java.util.ArrayList; * @author Simon Johnston */ public class DerbyDialect extends DB2Dialect { + private static final Logger log = LoggerFactory.getLogger( DerbyDialect.class ); + + private int driverVersionMajor; + private int driverVersionMinor; public DerbyDialect() { super(); registerFunction( "concat", new DerbyConcatFunction() ); registerFunction( "trim", new DerbyTrimFunctionEmulation() ); + determineDriverVersion(); } + /*package*/ void determineDriverVersion() { + try { + // locate the derby sysinfo class and query its version info + final Class sysinfoClass = ReflectHelper.classForName( "org.apache.derby.tools.sysinfo", this.getClass() ); + final Method majorVersionGetter = sysinfoClass.getMethod( "getMajorVersion", ReflectHelper.NO_PARAM_SIGNATURE ); + final Method minorVersionGetter = sysinfoClass.getMethod( "getMinorVersion", ReflectHelper.NO_PARAM_SIGNATURE ); + driverVersionMajor = ( (Integer) majorVersionGetter.invoke( null, ReflectHelper.NO_PARAMS ) ).intValue(); + driverVersionMinor = ( (Integer) minorVersionGetter.invoke( null, ReflectHelper.NO_PARAMS ) ).intValue(); + } + catch ( Exception e ) { + log.warn( "Unable to load/access derby driver class sysinfo to check versions : " + e ); + driverVersionMajor = -1; + driverVersionMinor = -1; + } + } + + /*package*/ boolean isTenPointFiveReleaseOrNewer() { + return driverVersionMajor > 10 || ( driverVersionMajor == 10 && driverVersionMinor >= 5 ); + } + + /** * This is different in Cloudscape to DB2. */ @@ -83,11 +114,75 @@ public class DerbyDialect extends DB2Dialect { } public boolean supportsLimit() { - return false; + return isTenPointFiveReleaseOrNewer(); } public boolean supportsLimitOffset() { - return false; + return isTenPointFiveReleaseOrNewer(); + } + + /** + * {@inheritDoc} + *

+ * From Derby 10.5 Docs: + * 

+	 * Query
+	 * [ORDER BY clause]
+	 * [result offset clause]
+	 * [fetch first clause]
+	 * [FOR UPDATE clause]
+	 * [WITH {RR|RS|CS|UR}]
+	 *
+ */ + public String getLimitString(String query, final int offset, final int limit) { + StringBuffer sb = new StringBuffer(query.length() + 50); + + final String normalizedSelect = query.toLowerCase().trim(); + final int forUpdateIndex = normalizedSelect.lastIndexOf( "for update") ; + + if ( hasForUpdateClause( forUpdateIndex ) ) { + sb.append( query.substring( 0, forUpdateIndex-1 ) ); + } + else if ( hasWithClause( normalizedSelect ) ) { + sb.append( query.substring( 0, getWithIndex( query ) - 1 ) ); + } + else { + sb.append( query ); + } + + if ( offset == 0 ) { + sb.append( " fetch first " ); + } + else { + sb.append( " offset " ).append( offset ).append( " rows fetch next " ); + } + + sb.append( limit ).append( " rows only" ); + + if ( hasForUpdateClause( forUpdateIndex ) ) { + sb.append(' '); + sb.append( query.substring( forUpdateIndex ) ); + } + else if ( hasWithClause( normalizedSelect ) ) { + sb.append( ' ' ).append( query.substring( getWithIndex( query ) ) ); + } + return sb.toString(); + } + + private boolean hasForUpdateClause(int forUpdateIndex) { + return forUpdateIndex >= 0; + } + + private boolean hasWithClause(String normalizedSelect){ + return normalizedSelect.startsWith( "with ", normalizedSelect.length()-7 ); + } + + private int getWithIndex(String querySelect) { + int i = querySelect.lastIndexOf( "with " ); + if ( i < 0 ) { + i = querySelect.lastIndexOf( "WITH " ); + } + return i; } public String getQuerySequencesString() { diff --git a/core/src/test/java/org/hibernate/dialect/DerbyDialectTestCase.java b/core/src/test/java/org/hibernate/dialect/DerbyDialectTestCase.java new file mode 100644 index 0000000000..b42119e0c1 --- /dev/null +++ b/core/src/test/java/org/hibernate/dialect/DerbyDialectTestCase.java @@ -0,0 +1,93 @@ +/* + * Hibernate, Relational Persistence for Idiomatic Java + * + * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by + * third-party contributors as indicated by either @author tags or express + * copyright attribution statements applied by the authors. All + * third-party contributions are distributed under license by Red Hat Inc. + * + * This copyrighted material is made available to anyone wishing to use, modify, + * copy, or redistribute it subject to the terms and conditions of the GNU + * Lesser General Public License, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License + * for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this distribution; if not, write to: + * Free Software Foundation, Inc. + * 51 Franklin Street, Fifth Floor + * Boston, MA 02110-1301 USA + */ +package org.hibernate.dialect; + +import junit.framework.TestCase; + +/** + * Testing of patched support for Derby limit and ofset queries; see HHH-3972 + * + * @author Evan Leonard + */ +public class DerbyDialectTestCase extends TestCase { + + private static class LocalDerbyDialect extends DerbyDialect { + protected boolean isTenPointFiveReleaseOrNewer() { + return true; // for test sake :) + } + } + + public void testInsertLimitClause() { + final int limit = 50; + final String input = "select * from tablename t where t.cat = 5"; + final String expected = "select * from tablename t where t.cat = 5 fetch first " + limit + " rows only"; + + final String actual = new LocalDerbyDialect().getLimitString( input, 0, limit ); + assertEquals( expected, actual ); + } + + public void testInsertLimitWithOffsetClause() { + final int limit = 50; + final int offset = 200; + final String input = "select * from tablename t where t.cat = 5"; + final String expected = "select * from tablename t where t.cat = 5 offset " + offset + " rows fetch next " + limit + " rows only"; + + final String actual = new LocalDerbyDialect().getLimitString( input, offset, limit ); + assertEquals( expected, actual ); + } + + + public void testInsertLimitWithForUpdateClause() { + final int limit = 50; + final int offset = 200; + final String input = "select c11 as col1, c12 as col2, c13 as col13 from t1 for update of c11, c13"; + final String expected = "select c11 as col1, c12 as col2, c13 as col13 from t1 offset " + offset + + " rows fetch next " + limit + " rows only for update of c11, c13"; + + final String actual = new LocalDerbyDialect().getLimitString( input, offset, limit ); + assertEquals( expected, actual ); + } + + public void testInsertLimitWithWithClause() { + final int limit = 50; + final int offset = 200; + final String input = "select c11 as col1, c12 as col2, c13 as col13 from t1 where flight_id between 'AA1111' and 'AA1112' with rr"; + final String expected = "select c11 as col1, c12 as col2, c13 as col13 from t1 where flight_id between 'AA1111' and 'AA1112' offset " + offset + + " rows fetch next " + limit + " rows only with rr"; + + final String actual = new LocalDerbyDialect().getLimitString( input, offset, limit ); + assertEquals( expected, actual ); + } + + public void testInsertLimitWithForUpdateAndWithClauses() { + final int limit = 50; + final int offset = 200; + final String input = "select c11 as col1, c12 as col2, c13 as col13 from t1 where flight_id between 'AA1111' and 'AA1112' for update of c11,c13 with rr"; + final String expected = "select c11 as col1, c12 as col2, c13 as col13 from t1 where flight_id between 'AA1111' and 'AA1112' offset " + offset + + " rows fetch next " + limit + " rows only for update of c11,c13 with rr"; + + final String actual = new LocalDerbyDialect().getLimitString( input, offset, limit ); + assertEquals( expected, actual ); + } +}