基于SqlServer+hibernate的简单分页查询

目前项目中用分页查询数据的方式，通过webService把数据循环查询出来传给对方存储，用到了分页。在此我们只需要看分页逻辑代码（相当于ServiceImpl），和Dao层代码（分页查询的SQL）即可。

分页逻辑代码块如下（放在ServiceImpl里）：

try {

/****************** 分页每次取100条记录 **********************/

// 总记录数
int totalNum = wsCisInPatRegDao.queryTotalNum();
System.out.println("总记录数"+totalNum);
// 每页数量
int pageSize = 100;
// 取余数值，根据此值判断页数是否加1
int tempValue = totalNum % pageSize;
// 循环次数（页数）
int pageNum;
// 如果总记录数除以页数整除，则结果为页数，否则页数为结果+1
if (tempValue != 0) {
pageNum = totalNum / pageSize + 1;
} else {
pageNum = totalNum / pageSize;
}
// 循环，每次取100条记录 循环次数为页数
for (int i = 0; i < pageNum; i++) {
List<WsCISINPATREG> list = null;
// 如每次取行号为如下以此类推的数据：1-100条 101-200条 201-300条
// 从数据库查询数据
list = wsCisInPatRegDao.pageQuery(1+i*pageSize,pageSize*(i+1));
// 将数据转化成要求格式
List<CISINPATREG> returnList= WsCISINPATREGVo.changeFromat(list);

}

DaoImpl

/**
* 查询总记录数
*/
@Override
public Integer queryTotalNum() {
List<WsCISINPATREG> returnlist = new ArrayList<WsCISINPATREG>();
String sql = " select count(*) as \"totalNum\" "
+ "from T_VISIT_RECORD v left join T_CIS_MAIN c on v.HIS_NO=c.HIS_NO "
+ "left join T_DIAGNOSIS d on v.HIS_NO=d.HIS_NO and d.BMLX='0' and d.ZDLB='2' "
+ "where v.TREAT_TYPE='2' ";
returnlist = super.getBySQL(sql, WsCISINPATREG.class, false, null);
return returnlist.get(0).getTotalNum();
}

/**
* 返回SQL语句
* @return
*/
public static String getSql() {
String sql = " select  distinct dbo.NumberConversion(v.HIS_NO)  as \"visitid\","
+ "c.YLJGDM as \"branchcode\","
+ "dbo.NumberConversion(v.PAT_ID) as \"patid\","
+ "v.HIS_NO as \"visitno\","
+ "c.BAH as \"mrno\","
+ "v.BED_NO as \"bedid\","
+ "dbo.NumberConversion(v.STATE) as \"state\","
+ "dbo.NumberConversion(c.ZYYSGH) as \"residentdoctor\","
+ "dbo.NumberConversion(c.ZZYSGH) as \"attendingdoctor\","
+ "dbo.NumberConversion(c.ZRYSGH) as \"chiefdoctor\","
+ "dbo.NumberConversion(v.ADMISSION_DEPT_CODE) as \"indeptid\","
+ "dbo.NumberConversion(c.RYBQ) as \"inwardid\","
+ "dbo.NumberConversion(c.CYFS) as \"outway\","
+ " dbo.NumberConversion(c.BXLX) as \"feenature\","
+ "dbo.DateConversion(v.TREAT_DATE) as \"regtime\","
+ "dbo.DateConversion(v.LEAVE_TIME) as \"clnouttime\","
+ "dbo.NumberConversion(v.TREAT_TYPE) as \"inway\","
+ "d.ZDBM as \"indiagcode\","
+ "d.ZDSM as \"indiagname\","
+ "v.CARD_NUMBER as \"carddata\","
+ "dbo.NumberConversion(v.NURSING_LEVEL) as \"carelevel\" ,"
+" dbo.NumberConversion(v.ADMISSION_DEPT_CODE) as \"deptid\", "
+" dbo.NumberConversion(v.WARD_CODE) as \"wardid\" "
+ "from T_VISIT_RECORD v left join T_CIS_MAIN c on v.HIS_NO=c.HIS_NO "
+ "left join T_DIAGNOSIS d on v.HIS_NO=d.HIS_NO and d.BMLX='0' and d.ZDLB='2' "
+ "left join T_TRANSFER_RECORD t on v.HIS_NO=t.HIS_NO "
+ " where v.TREAT_TYPE='2' ";
return sql;

}

/**
* 分页查询
*/
@Override
public List<WsCISINPATREG> pageQuery(int beginNum, int endNum) {
List<WsCISINPATREG> returnlist = new ArrayList<WsCISINPATREG>();
String querySl = WsCisInPatRegDaoImpl.getSql();
String sql = "SELECT * FROM (SELECT t.*,ROW_NUMBER() OVER (ORDER BY t.visitid desc) AS rowNum FROM ("
+ querySl
+ ") t) t1  WHERE rowNum >="
+ beginNum
+ " AND rowNum <=" + endNum + "";
returnlist = super.getBySQL(sql, WsCISINPATREG.class, false, null);
return returnlist;
}

这里在说明一下分页的原理。

分页最主要的就是两次查询：

第一次，查询出满足当前条件的总记录数，用于计算页数等。比如，select count(*) from Table where coloum='查询条件';。

第二次，才是根据第一次查询条件得出的相关参数，进行分页查询，通常页数是前端发送过来的，在我的这个案例里面并不是，我的这个属于循环分页取得所有的数据。

不同的数据库分页语句不一样，这个大家可以自行搜索，然后写语句的时候放到数据库客户端中调试。如果在程序中调试费时间，因为每次都要重新部署启动服务器。