HHH-2176 DB2 setMaxResults problem in Hibernate 3.1.3

hibernate-core/src/main/java/org/hibernate/dialect/DB2Dialect.java

@@ -207,73 +207,72 @@ public class DB2Dialect extends Dialect {
 	public boolean supportsLimit() {
 		return true;
 	}
-
+	public boolean supportsVariableLimit() {
-	/*public String getLimitString(String sql, boolean hasOffset) {
+		return false;
-		StringBuffer rownumber = new StringBuffer(50)
-			.append(" rownumber() over(");
-		int orderByIndex = sql.toLowerCase().indexOf("order by");
-		if (orderByIndex>0) rownumber.append( sql.substring(orderByIndex) );
-		rownumber.append(") as row_,");
-		StringBuffer pagingSelect = new StringBuffer( sql.length()+100 )
-			.append("select * from ( ")
-			.append(sql)
-			.insert( getAfterSelectInsertPoint(sql)+16, rownumber.toString() )
-			.append(" ) as temp_ where row_ ");
-		if (hasOffset) {
-			pagingSelect.append("between ?+1 and ?");
-		}
-		else {
-			pagingSelect.append("<= ?");
-		}
-		return pagingSelect.toString();
-	}*/
-
-	/**
-	 * Render the <tt>rownumber() over ( .... ) as rownumber_,</tt> 
-	 * bit, that goes in the select list
-	 */
-	private String getRowNumber(String sql) {
-		StringBuffer rownumber = new StringBuffer(50)
-			.append("rownumber() over(");
-
-		int orderByIndex = sql.toLowerCase().indexOf("order by");
-
-		if ( orderByIndex>0 && !hasDistinct(sql) ) {
-			rownumber.append( sql.substring(orderByIndex) );
 	}
 
-		rownumber.append(") as rownumber_,");
+//	/**
-
+//	 * Render the <tt>rownumber() over ( .... ) as rownumber_,</tt>
-		return rownumber.toString();
+//	 * bit, that goes in the select list
+//	 */
+//	private String getRowNumber(String sql) {
+//		StringBuffer rownumber = new StringBuffer(50)
+//			.append("rownumber() over(");
+//
+//		int orderByIndex = sql.toLowerCase().indexOf("order by");
+//
+//		if ( orderByIndex>0 && !hasDistinct(sql) ) {
+//			rownumber.append( sql.substring(orderByIndex) );
+//		}
+//
+//		rownumber.append(") as rownumber_,");
+//
+//		return rownumber.toString();
+//	}
+//
+//	public String getLimitString(String sql, boolean hasOffset) {
+//		int startOfSelect = sql.toLowerCase().indexOf("select");
+//
+//		StringBuffer pagingSelect = new StringBuffer( sql.length()+100 )
+//				.append( sql.substring(0, startOfSelect) )	// add the comment
+//				.append("select * from ( select ") 			// nest the main query in an outer select
+//				.append( getRowNumber(sql) ); 				// add the rownnumber bit into the outer query select list
+//
+//		if ( hasDistinct(sql) ) {
+//			pagingSelect.append(" row_.* from ( ")			// add another (inner) nested select
+//					.append( sql.substring(startOfSelect) ) // add the main query
+//					.append(" ) as row_"); 					// close off the inner nested select
+//		}
+//		else {
+//			pagingSelect.append( sql.substring( startOfSelect + 6 ) ); // add the main query
+//		}
+//
+//		pagingSelect.append(" ) as temp_ where rownumber_ ");
+//
+//		//add the restriction to the outer select
+//		if (hasOffset) {
+//			pagingSelect.append("between ?+1 and ?");
+//		}
+//		else {
+//			pagingSelect.append("<= ?");
+//		}
+//
+//		return pagingSelect.toString();
+//	}
+public String getLimitString(String sql, int offset, int limit) {
+	if ( offset == 0 ) {
+		return sql + " fetch first " + limit + " rows only";
 	}
-
+	StringBuilder pagingSelect = new StringBuilder( sql.length() + 200 )
-	public String getLimitString(String sql, boolean hasOffset) {
+			.append(
-		int startOfSelect = sql.toLowerCase().indexOf("select");
+					"select * from ( select inner2_.*, rownumber() over(order by order of inner2_) as rownumber_ from ( "
-
+			)
-		StringBuffer pagingSelect = new StringBuffer( sql.length()+100 )
+			.append( sql )  //nest the main query in an outer select
-				.append( sql.substring(0, startOfSelect) )	// add the comment
+			.append( " fetch first " )
-				.append("select * from ( select ") 			// nest the main query in an outer select
+			.append( limit )
-				.append( getRowNumber(sql) ); 				// add the rownnumber bit into the outer query select list
+			.append( " rows only ) as inner2_ ) as inner1_ where rownumber_ > " )
-
+			.append( offset )
-		if ( hasDistinct(sql) ) {
+			.append( " order by rownumber_" );
-			pagingSelect.append(" row_.* from ( ")			// add another (inner) nested select
-					.append( sql.substring(startOfSelect) ) // add the main query
-					.append(" ) as row_"); 					// close off the inner nested select
-		}
-		else {
-			pagingSelect.append( sql.substring( startOfSelect + 6 ) ); // add the main query
-		}
-
-		pagingSelect.append(" ) as temp_ where rownumber_ ");
-
-		//add the restriction to the outer select
-		if (hasOffset) {
-			pagingSelect.append("between ?+1 and ?");
-		}
-		else {
-			pagingSelect.append("<= ?");
-		}
-
 	return pagingSelect.toString();
 }
 
@@ -288,10 +287,10 @@ public class DB2Dialect extends Dialect {
 	public int convertToFirstRowValue(int zeroBasedFirstResult) {
 		return zeroBasedFirstResult;
 	}
-
+//
-	private static boolean hasDistinct(String sql) {
+//	private static boolean hasDistinct(String sql) {
-		return sql.toLowerCase().indexOf("select distinct")>=0;
+//		return sql.toLowerCase().indexOf("select distinct")>=0;
-	}
+//	}
 
 	public String getForUpdateString() {
 		return " for read only with rs";

hibernate-core/src/test/java/org/hibernate/test/pagination/PaginationTest.java

@@ -38,6 +38,7 @@ import org.hibernate.testing.RequiresDialectFeature;
 import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 /**
  * @author Gavin King
@@ -145,6 +146,30 @@ public class PaginationTest extends BaseCoreFunctionalTestCase {
 		assertEquals( 1, result.size() );
 		assertEquals( 99, ( ( DataPoint ) result.get( 0 ) ).getSequence() );
 
+		result = session.createQuery("select distinct description from DataPoint order by description")
+				.setFirstResult( 2 )
+				.setMaxResults( 3 )
+				.list();
+		assertEquals( 3, result.size() );
+		assertEquals( "Description: 2", result.get(0));
+		assertEquals( "Description: 3", result.get(1));
+		assertEquals( "Description: 4", result.get(2));
+
+		result = session.createSQLQuery( "select description, xval, yval from DataPoint order by xval, yval" )
+				.setFirstResult( 2 )
+				.setMaxResults( 5 )
+				.list();
+		assertEquals( 5, result.size() );
+		Object[] row = (Object[]) result.get(0);
+		assertTrue( row[0] instanceof String);
+
+		result = session.createSQLQuery( "select * from DataPoint order by xval, yval" )
+				.setFirstResult( 2 )
+				.setMaxResults( 5 )
+				.list();
+		assertEquals( 5, result.size() );
+
+
 		session.getTransaction().commit();
 		session.close();
 
@@ -175,6 +200,7 @@ public class PaginationTest extends BaseCoreFunctionalTestCase {
 			BigDecimal x = new BigDecimal( i * 0.1d ).setScale( 19, BigDecimal.ROUND_DOWN );
 			dataPoint.setX( x );
 			dataPoint.setY( new BigDecimal( Math.cos( x.doubleValue() ) ).setScale( 19, BigDecimal.ROUND_DOWN ) );
+			dataPoint.setDescription("Description: " + i%5);
 			session.save( dataPoint );
 		}
 		session.getTransaction().commit();