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HHH-2176 DB2 setMaxResults problem in Hibernate 3.1.3

This commit is contained in:
Strong Liu 2011-06-07 17:52:48 +08:00
parent f78c79d676
commit 2077b5f43c
2 changed files with 95 additions and 70 deletions
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139
hibernate-core/src/main/java/org/hibernate/dialect/DB2Dialect.java
View File

@ -207,75 +207,74 @@ public class DB2Dialect extends Dialect {
public boolean supportsLimit() {
return true;
}
public boolean supportsVariableLimit() {
return false;
}
/*public String getLimitString(String sql, boolean hasOffset) {
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("<= ?");
// /**
// * 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_,");
//
// 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 )
.append(
"select * from ( select inner2_.*, rownumber() over(order by order of inner2_) as rownumber_ from ( "
)
.append( sql ) //nest the main query in an outer select
.append( " fetch first " )
.append( limit )
.append( " rows only ) as inner2_ ) as inner1_ where rownumber_ > " )
.append( offset )
.append( " order by rownumber_" );
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_,");
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();
}
}
/**
* DB2 does have a one-based offset, however this was actually already handled in the limit string building
@ -288,10 +287,10 @@ public class DB2Dialect extends Dialect {
public int convertToFirstRowValue(int zeroBasedFirstResult) {
return zeroBasedFirstResult;
}
private static boolean hasDistinct(String sql) {
return sql.toLowerCase().indexOf("select distinct")>=0;
}
//
// private static boolean hasDistinct(String sql) {
// return sql.toLowerCase().indexOf("select distinct")>=0;
// }
public String getForUpdateString() {
return " for read only with rs";

26
hibernate-core/src/test/java/org/hibernate/test/pagination/PaginationTest.java
View File

@ -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();