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BATCH-760: added a JdbcPagingQueryProvider abstraction and an SQL:2003 windowing functions implementation

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trisberg
2008-08-22 19:51:56 +00:00
parent fac1c2b22b
commit ecc19e96ff
3 changed files with 188 additions and 0 deletions
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70
spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/support/JdbcPagingQueryProvider.java Normal file
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/*
* Copyright 2006-2008 the original author or authors.
*
* Licensed 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.
*/
package org.springframework.batch.item.database.support;
/**
* Interface defining the functionality to be provided for generating paging queries for use with JDBC.
*
* Any usage must provide the select clause, from clause and optionally a where clause. In addition a
* single column sort key must be defined. This sort key will be used to provide the paging functinality.
* It is recommended that there should be an index for the sort key to provide better performance.
*
* @author Thomas Risberg
* @since 2.0
*/
public interface JdbcPagingQueryProvider {
/**
* Generate the query that will provide the first page, limited by the page size.
*
* @param pageSize number of rows to read for each page
* @param selectClause the columns that are part of the selct clause
* @param fromClause the table(s) that are part of the from clause
* @param whereClause the conditions that are part of the where clause
* @param sortKey the single column used for sorting
* @return the generated query
*/
String generateFirstPageQuery(int pageSize, String selectClause, String fromClause, String whereClause, String sortKey);
/**
* Generate the query that will provide the first page, limited by the page size.
*
* @param pageSize number of rows to read for each page
* @param selectClause the columns that are part of the selct clause
* @param fromClause the table(s) that are part of the from clause
* @param whereClause the conditions that are part of the where clause
* @param sortKey the single column used for sorting
* @return the generated query
*/
String generateRemainingPagesQuery(int pageSize, String selectClause, String fromClause, String whereClause, String sortKey);
/**
*
* Generate the query that will provide the jump to item query. The itemIndex provided could be in the middle of
* the page and together with the page size it will be used to calculate the last index of the preceding page
* to be able to retrieve the sort key for this row.
*
* @param itemIndex the index for the next item to be read
* @param pageSize number of rows to read for each page
* @param selectClause the columns that are part of the selct clause
* @param fromClause the table(s) that are part of the from clause
* @param whereClause the conditions that are part of the where clause
* @param sortKey the single column used for sorting
* @return the generated query
*/
String generateJumpToItemQuery(int itemIndex, int pageSize, String selectClause, String fromClause, String whereClause, String sortKey);
}

64
spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/support/SqlWindowingPagingQueryProvider.java Normal file
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/*
* Copyright 2006-2008 the original author or authors.
*
* Licensed 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.
*/
package org.springframework.batch.item.database.support;
/**
* Generic Paging Query Provider using standard SQL:2003 windowing functions. These features are supported by
* DB2, Oracle, SQL Server 2005, Sybase and Apache Derby version 10.4.1.3
*
* @author Thomas Risberg
* @since 2.0
*/
public class SqlWindowingPagingQueryProvider implements JdbcPagingQueryProvider {
public String generateFirstPageQuery(int pageSize, String selectClause, String fromClause, String whereClause, String sortKey) {
StringBuilder sql = new StringBuilder();
sql.append("SELECT * FROM ( ");
sql.append("SELECT ").append(selectClause).append(", ");
sql.append("ROW_NUMBER() OVER (ORDER BY ").append(sortKey).append(" ASC) AS ROW_NUMBER");
sql.append(" FROM ").append(fromClause).append(whereClause == null ? "" : " WHERE " + whereClause);
sql.append(") WHERE ROW_NUMBER <= ").append(pageSize);
return sql.toString();
}
public String generateRemainingPagesQuery(int pageSize, String selectClause, String fromClause, String whereClause, String sortKey) {
StringBuilder sql = new StringBuilder();
sql.append("SELECT * FROM ( ");
sql.append("SELECT ").append(selectClause).append(", ");
sql.append("ROW_NUMBER() OVER (ORDER BY ").append(sortKey).append(" ASC) AS ROW_NUMBER");
sql.append(" FROM ").append(fromClause).append(" WHERE ").append(sortKey).append(" > ?");
sql.append(whereClause == null ? "" : " AND " + whereClause);
sql.append(") WHERE ROW_NUMBER <= ").append(pageSize);
return sql.toString();
}
public String generateJumpToItemQuery(int itemIndex, int pageSize, String selectClause, String fromClause, String whereClause, String sortKey) {
int page = itemIndex / pageSize;
int lastRowNum = (page * pageSize);
StringBuilder sql = new StringBuilder();
sql.append("SELECT SORT_KEY FROM ( ");
sql.append("SELECT ").append(sortKey).append(" AS SORT_KEY, ");
sql.append("ROW_NUMBER() OVER (ORDER BY ").append(sortKey).append(" ASC) AS ROW_NUMBER");
sql.append(" FROM ").append(fromClause).append(whereClause == null ? "" : " WHERE " + whereClause);
sql.append(") WHERE ROW_NUMBER = ").append(lastRowNum);
return sql.toString();
}
}

54
spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/support/SqlWindowingPagingQueryProviderTests.java Normal file
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/*
* Copyright 2006-2008 the original author or authors.
*
* Licensed 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.
*/
package org.springframework.batch.item.database.support;
import static org.junit.Assert.*;
import org.junit.Test;
/**
* @author Thomas Risberg
*/
public class SqlWindowingPagingQueryProviderTests {
JdbcPagingQueryProvider pagingQueryProvider = new SqlWindowingPagingQueryProvider();
private int pageSize = 100;
private String selectClause = "id, name, age";
private String fromClause = "foo";
private String whereClaues = "bar = 1";
private String sortKey = "id";
@Test
public void testGenerateFirstPageQuery() {
String sql = "SELECT * FROM ( SELECT id, name, age, ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW_NUMBER FROM foo WHERE bar = 1) WHERE ROW_NUMBER <= 100";
String s = pagingQueryProvider.generateFirstPageQuery(pageSize, selectClause, fromClause, whereClaues, sortKey);
assertEquals("", sql, s);
}
@Test
public void testGenerateRemainingPagesQuery() {
String sql = "SELECT * FROM ( SELECT id, name, age, ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW_NUMBER FROM foo WHERE id > ? AND bar = 1) WHERE ROW_NUMBER <= 100";
String s = pagingQueryProvider.generateRemainingPagesQuery(pageSize, selectClause, fromClause, whereClaues, sortKey);
assertEquals("", sql, s);
}
@Test
public void testGenerateJumpToItemQuery() {
String sql = "SELECT SORT_KEY FROM ( SELECT id AS SORT_KEY, ROW_NUMBER() OVER (ORDER BY id ASC) AS ROW_NUMBER FROM foo WHERE bar = 1) WHERE ROW_NUMBER = 100";
String s = pagingQueryProvider.generateJumpToItemQuery(145, pageSize, selectClause, fromClause, whereClaues, sortKey);
assertEquals("", sql, s);
}
}