spring data jpa 1.9/1.10 复杂sql分页查询

基于jpa

controller中创建Pageable实现类PageRequest

PageRequest pageRequest = new PageRequest(page, size,new Sort(Sort.Direction.DESC, "update_time") );//

dao代码如下

public interface DataNodeDao extends PagingAndSortingRepository<TDataNode, Long> {
@Query(value = "SELECT dn.* FROM data_node dn LEFT JOIN data_device_rel ddr ON dn.id = ddr.data_id LEFT JOIN device_station_rel dsr ON ddr.device_id = dsr.device_id LEFT JOIN user_station us ON dsr.station_id = us.station_id WHERE us.organization_id = ?1  AND dn.STATUS = ?2  /*#pageable*/",
countQuery = "SELECT count(dn.id) FROM data_node dn LEFT JOIN data_device_rel ddr ON dn.id = ddr.data_id LEFT JOIN device_station_rel dsr ON ddr.device_id = dsr.device_id LEFT JOIN user_station us ON dsr.station_id = us.station_id WHERE us.organization_id = ?1 AND dn.STATUS = ?2 ",nativeQuery = true)
Page<TDataNode> userDataNodeList(int organizationId, int status, Pageable page);
@Query("select dn from TDataNode dn where  dn.status=?1")
Page<TDataNode> userDataNodeList(int status, Pageable page);

第一种使用nativeQuery，需要加上#pageable，不然会报错，spring源码如下，如果要使用分页，必须包含#pageable或者#sort

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.data.jpa.repository.query;

import javax.persistence.EntityManager;
import javax.persistence.Query;
import org.springframework.data.repository.query.EvaluationContextProvider;
import org.springframework.data.repository.query.Parameters;
import org.springframework.expression.spel.standard.SpelExpressionParser;

final class NativeJpaQuery extends AbstractStringBasedJpaQuery {
public NativeJpaQuery(JpaQueryMethod method, EntityManager em, String queryString, EvaluationContextProvider evaluationContextProvider, SpelExpressionParser parser) {
super(method, em, queryString, evaluationContextProvider, parser);
Parameters<?, ?> parameters = method.getParameters();
boolean hasPagingOrSortingParameter = parameters.hasPageableParameter() || parameters.hasSortParameter();
boolean containsPageableOrSortInQueryExpression = queryString.contains("#pageable") || queryString.contains("#sort");
if (hasPagingOrSortingParameter && !containsPageableOrSortInQueryExpression) {
throw new InvalidJpaQueryMethodException("Cannot use native queries with dynamic sorting and/or pagination in method " + method);
}
}

protected Query createJpaQuery(String queryString) {
return this.getQueryMethod().isQueryForEntity() ? this.getEntityManager().createNativeQuery(queryString, this.getQueryMethod().getReturnedObjectType()) : this.getEntityManager().createNativeQuery(queryString);
}
}

如果使用第二种hql，则不用做额外处理

最终jpa会在sql末尾自动拼接

order by dn.update_time desc limit **

官网文档

https://docs.spring.io/spring-data/jpa/docs/current/reference/html/

基于JdbcTemplate

jpa的动态条件查询Specification太复杂，可读性比较差，还不如直接用jdbcTemplate，封装的类如下

package common.util;

import org.springframework.core.convert.converter.Converter;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import java.util.Iterator;
import java.util.List;

/**
* Created by wmf on 2017/5/23.
*/
public class JPAPageUtils<T> {

public  Page<T> getPage(RowMapper<T> mapper, JdbcTemplate jt, String sql, int currentPage, int pageSize){
int totalRows = jt.queryForObject("select count(*) from ("+sql+") t9", Integer.class);
int total;
// 总行数 % 每页行数 = 0
if (totalRows % pageSize == 0) {
total= totalRows / pageSize;
} else {
// 总行数 % 每页行数 != 0
total= totalRows / pageSize + 1;
}
List<T> list = jt.query("select t9.* from ("+sql+") t9 limit ?,?",
new Object[]{(currentPage * pageSize), pageSize},mapper);
Page<T> result= new Page<T>() {
@Override
public Iterator<T> iterator() {
return null;
}

@Override
public int getTotalPages() {
return total;
}

@Override
public long getTotalElements() {
return totalRows;
}

@Override
public int getNumber() {
return currentPage;
}

@Override
public int getSize() {
return pageSize;
}

@Override
public int getNumberOfElements() {
return 0;
}

@Override
public List<T> getContent() {
return list;
}

@Override
public boolean hasContent() {
return false;
}

@Override
public Sort getSort() {
return null;
}

@Override
public boolean isFirst() {
return this.getNumber()==0;
}

@Override
public boolean isLast() {
return this.getTotalPages()==(this.getNumber()+1);
}

@Override
public boolean hasNext() {
return false;
}

@Override
public boolean hasPrevious() {
return false;
}

@Override
public Pageable nextPageable() {
return null;
}

@Override
public Pageable previousPageable() {
return null;
}

@Override
public <S> Page<S> map(Converter<? super T, ? extends S> converter) {
return null;
}
};
return result;
}

}

获取mapper的写法

public static RowMapper<TStation> getMapper(){
RowMapper<TStation> mapper=new RowMapper<TStation>() {
@Override
public TStation mapRow(ResultSet rs, int i) throws SQLException {
TStation s = new TStation();
s.setId(rs.getInt("id"));
s.setName(rs.getString("name"));
return s;
}
public boolean isExistColumn(ResultSet rs, String columnName) {
try {
if (rs.findColumn(columnName) > 0 ) {
return true;
}
}
catch (SQLException e) {
return false;
}
return false;
}
};
return mapper;
}

使用

JPAPageUtils<TStation> station=new JPAPageUtils<TStation>();
...
station.getPage(getMapper(),jdbcTemplate,sb.toString(),number,size);