//  總頁數
int pages=0;
//  查詢總行數的SQL
String rowSql= "select count(*) from "+ table_name;
......
//  判斷頁數,如果是頁大小的整數倍就為rows/pageSize如果不是整數倍就為rows/pageSize+1
if (rows % pageSize == 0) {
   pages = rows / pageSize;
} else {
   pages = rows / pageSize + 1;
}

start :開始行數  currentPageNo:當前頁碼  pagesize:每頁條數

1，mysql：  mysql  start 從0開始

select * from table_name  limit  start ,pagesize
-- 傳遞 currentPageNo（頁碼）、pageSize（每頁條數）
select * from table limit (currentPageNo-1)*pageSize,pageSize;
--當數量到達萬級以上，利用主鍵或者唯一索引進行資料分頁，提高效能
select * from table where _id > (currentPageNo-1)*pageSize limit pageSize; 
 
-- 同上並加上條件對資料排序返回
select * from table where _id > (currentPageNo-1)*pageSize order by _id limit pageSize; 

2，pgsql ： start 從0開始

select * from table_name  limit  pageSize  offset  start;
-- 當start為0可以簡寫如下
select * from table_name limit pageSize

--排序
select * from table_name  order
 
 by xxxx  limit pageSize   offset start;

--加當前頁碼currentPageNo
select * from xxx limit pagesize offset （currentPageNo－1）*pagesize;

3，Oracle

--在Oracle中實現分頁的方法大致分為兩種，用ROWNUM關鍵字和用ROWID關鍵字
--ROWNUM
select * from (
    select rownum as row_no, t.* from  table_name  t  where xxx='xxx' and 
    rownum <= pageSize*currentPageNo  )
table_alias where table_alias.row_no > pageSize*(currentPageNo -1); 

--ROWID
SELECT *
  FROM (SELECT RID
          FROM (SELECT R.RID, ROWNUM LINENUM
                  FROM (SELECT ROWID RID
                          FROM TABLE1
                         WHERE TABLE1_ID = XX
                         ORDER BY order_date DESC) R
                 WHERE ROWNUM <= 20)
         WHERE LINENUM >= 10) T1,
       TABLE1 T2
 WHERE T1.RID = T2.ROWID;