大數據下的分頁語句
pageSize:一頁幾條數據
pageNumber:當前頁
mysql:
select * from students order by id limit " + pageSize*(pageNumber-1)+ "," + pageSize;
oracle:
select * from (select *,rownum rid from (select * fromstudents order by postime desc) where rid<=" + pagesize*pagenumber +") as t where t>" +pageSize*(pageNumber-1);
在業務中處理分頁:
// 定義的總記錄數 int dataCount = 0; // 定義當前頁 // pageNum = 1; // 定義總頁數 int pageCount = 0; // 定義每頁顯示條數 int pageSize = 30; // 開始索引 int startIndex = 0; //統計總記錄數 dataCount=photoService.countPhoto(); //計算共多少頁 if(dataCount%pageSize == 0){ pageCount = dataCount/pageSize; }else { pageCount = dataCount/pageSize + 1; } if(pageNum!=0){ startIndex = (pageNum-1)*pageSize; }
SQL語句:select * from emp limit startIndex,30