Author: tfischer
Date: Thu Aug 16 13:34:35 2012
New Revision: 1373827
URL: http://svn.apache.org/viewvc?rev=1373827&view=rev
Log:
TORQUE-218: Enhance Derby adapter to use limit/offset functionality
Thanks to T. Schmidt for the patch
Added:
db/torque/torque4/trunk/torque-site/src/site/xdoc/documentation/other/database-howtos/derby-howto.xml
Modified:
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/AbstractAdapter.java
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/DerbyAdapter.java
db/torque/torque4/trunk/torque-site/src/site/site.xml
db/torque/torque4/trunk/torque-test/src/test/java/org/apache/torque/DataTest.java
Modified:
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/AbstractAdapter.java
URL:
http://svn.apache.org/viewvc/db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/AbstractAdapter.java?rev=1373827&r1=1373826&r2=1373827&view=diff
==============================================================================
---
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/AbstractAdapter.java
(original)
+++
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/AbstractAdapter.java
Thu Aug 16 13:34:35 2012
@@ -154,8 +154,8 @@ public abstract class AbstractAdapter im
}
/**
- * This method is used to check whether the database natively
- * supports limiting the size of the resultset.
+ * Returns whether the database can natively limit the size of the
ResultSet
+ * of a query.
*
* @return true if the database natively supports limiting the
* size of the resultset.
@@ -166,9 +166,8 @@ public abstract class AbstractAdapter im
}
/**
- * This method is used to check whether the database natively
- * supports returning results starting at an offset position other
- * than 0.
+ * Returns whether the database natively supports returning results
+ * starting at an offset position other than 0.
*
* @return true if the database natively supports returning
* results starting at an offset position other than 0.
Modified:
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/DerbyAdapter.java
URL:
http://svn.apache.org/viewvc/db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/DerbyAdapter.java?rev=1373827&r1=1373826&r2=1373827&view=diff
==============================================================================
---
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/DerbyAdapter.java
(original)
+++
db/torque/torque4/trunk/torque-runtime/src/main/java/org/apache/torque/adapter/DerbyAdapter.java
Thu Aug 16 13:34:35 2012
@@ -25,12 +25,13 @@ import java.sql.Statement;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
+import org.apache.torque.sql.Query;
/**
* This is used to connect to an embedded Apache Derby Database using
* the supplied JDBC driver.
*
- * @author <a href="mailto:[email protected]";>Henning P. Schmiedehausen</a>
+ * @author <a href="mailto:[email protected]";>Henning P. Schmiedehausen</a>,
tins
* @version $Id$
*/
public class DerbyAdapter extends AbstractAdapter
@@ -183,4 +184,62 @@ public class DerbyAdapter extends Abstra
{
return true;
}
+
+ /**
+ * Returns whether the database can natively limit the size of the
ResultSet
+ * of a query.
+ * Limit is supported since Derby 10.5.1.1.
+ *
+ * @return true.
+ */
+ @Override
+ public boolean supportsNativeLimit()
+ {
+ return true;
+ }
+
+ /**
+ * Returns whether the database natively supports returning results
+ * starting at an offset position other than 0.
+ * Offset is supported since Derby 10.5.1.1.
+ *
+ * @return true.
+ */
+ @Override
+ public boolean supportsNativeOffset()
+ {
+ return true;
+ }
+
+ /**
+ * Build Derby-style query with limit or offset.
+ * The resulting query may look like this:
+ * <pre>
+ * select * from TABLENAME fetch next 3 rows only;
+ * select * from TABLENAME offset 3 rows fetch next 3 rows only;
+ * </pre>
+ *
+ * @param query The query to modify.
+ * @param offset the offset value.
+ * @param limit the limit value.
+ */
+ @Override
+ public void generateLimits(Query query, long offset, int limit)
+ {
+ StringBuilder postLimit = new StringBuilder();
+
+ if (offset > 0)
+ {
+ postLimit.append(" OFFSET ").append(offset).append(" ROWS");
+ }
+
+ if (limit >= 0)
+ {
+ postLimit.append(" FETCH NEXT ").append(limit).append(" ROWS
ONLY");
+ }
+
+ query.setPostLimit(postLimit.toString());
+ query.setLimit(null);
+ query.setOffset(null);
+ }
}
Modified: db/torque/torque4/trunk/torque-site/src/site/site.xml
URL:
http://svn.apache.org/viewvc/db/torque/torque4/trunk/torque-site/src/site/site.xml?rev=1373827&r1=1373826&r2=1373827&view=diff
==============================================================================
--- db/torque/torque4/trunk/torque-site/src/site/site.xml (original)
+++ db/torque/torque4/trunk/torque-site/src/site/site.xml Thu Aug 16 13:34:35
2012
@@ -195,6 +195,7 @@
<menu name="Other Documentation">
<item name="Supported Databases"
href="/documentation/other/supported-databases.html"/>
<item name="Database Howtos"
href="/documentation/other/database-howtos/index.html" collapse="true">
+ <item name="Derby"
href="/documentation/other/database-howtos/derby-howto.html"/>
<item name="HSQLDB"
href="/documentation/other/database-howtos/hsqldb-howto.html"/>
<item name="MS SQL Server"
href="/documentation/other/database-howtos/mssql-howto.html"/>
<item name="MySQL"
href="/documentation/other/database-howtos/mysql-howto.html"/>
Added:
db/torque/torque4/trunk/torque-site/src/site/xdoc/documentation/other/database-howtos/derby-howto.xml
URL:
http://svn.apache.org/viewvc/db/torque/torque4/trunk/torque-site/src/site/xdoc/documentation/other/database-howtos/derby-howto.xml?rev=1373827&view=auto
==============================================================================
---
db/torque/torque4/trunk/torque-site/src/site/xdoc/documentation/other/database-howtos/derby-howto.xml
(added)
+++
db/torque/torque4/trunk/torque-site/src/site/xdoc/documentation/other/database-howtos/derby-howto.xml
Thu Aug 16 13:34:35 2012
@@ -0,0 +1,43 @@
+<?xml version="1.0"?>
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements. See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership. The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing,
+ software distributed under the License is distributed on an
+ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ KIND, either express or implied. See the License for the
+ specific language governing permissions and limitations
+ under the License.
+-->
+<document>
+
+ <properties>
+ <title>Derby Howto</title>
+ </properties>
+
+ <body>
+
+ <section name="Introduction">
+ This document contains hints for using Torque with HSQLDB.
+ </section>
+
+ <section name="Supported versions">
+
+ <p>
+ Derby 10.5.1.1 introduced support for limit and offset.
+ This is used in within Torque, so limit and offset does not
+ work for Derby < 10.5.1.1
+ </p>
+
+ </section>
+
+ </body>
+</document>
Modified:
db/torque/torque4/trunk/torque-test/src/test/java/org/apache/torque/DataTest.java
URL:
http://svn.apache.org/viewvc/db/torque/torque4/trunk/torque-test/src/test/java/org/apache/torque/DataTest.java?rev=1373827&r1=1373826&r2=1373827&view=diff
==============================================================================
---
db/torque/torque4/trunk/torque-test/src/test/java/org/apache/torque/DataTest.java
(original)
+++
db/torque/torque4/trunk/torque-test/src/test/java/org/apache/torque/DataTest.java
Thu Aug 16 13:34:35 2012
@@ -31,6 +31,7 @@ import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.torque.adapter.Adapter;
+import org.apache.torque.adapter.DerbyAdapter;
import org.apache.torque.adapter.MssqlAdapter;
import org.apache.torque.adapter.MysqlAdapter;
import org.apache.torque.criteria.Criteria;
@@ -184,13 +185,24 @@ public class DataTest extends BaseDataba
}
catch (TorqueException e)
{
- if (Torque.getDB(Torque.getDefaultDB()).supportsNativeLimit())
+ if (defaultAdapter.supportsNativeLimit())
{
- throw e;
+ if (!(defaultAdapter instanceof DerbyAdapter))
+ {
+ throw e;
+ }
+ else
+ {
+ log.error("testLimitOffset(): "
+ + "A limit of 0 is not supported for Derby");
+ }
+ }
+ else
+ {
+ log.error("testLimitOffset(): "
+ + "A limit of 0 is not supported for Databases "
+ + "without native limit support");
}
- log.error("testLimitOffset(): "
- + "A limit of 0 is not supported for Databases "
- + "without native limit support");
}
// check that Offset also works without limit
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