分页语句 mysql 、server sql、oracle的分页语句

 

取出sql表中第31到40的记录（以自动增长ID为主键）

sql server方案1：

    selecttop 10 * from t where id not in (select top 30 id from t order by id ) orde byid

sql server方案2：

    selecttop 10 * from t where id in (select top 40 id from t order by id) order by iddesc

 

mysql方案：select * from t order by idlimit 30,10

 

oracle方案：select* from (select rownum r,* from t where r<=40) where r>30

 

--------------------待整理进去的内容-------------------------------------

pageSize=20;

pageNo = 5;

 

1.分页技术1（直接利用sql语句进行分页，效率最高和最推荐的）

 

mysql:sql ="select * from articles limit " + (pageNo-1)*pageSize + ","+ pageSize;

oracle: sql ="select * from " +

                                                        "(selectrownum r,* from " +

                                                               "(select* from articles order by postime desc)" +

                                                        "whererownum<= " + pageNo*pageSize +") tmp " +

                                                 "wherer>" + (pageNo-1)*pageSize;

注释：第7行保证rownum的顺序是确定的，因为oracle的索引会造成rownum返回不同的值

简洋提示：没有order by时，rownum按顺序输出，一旦有了order by，rownum不按顺序输出了，这说明rownum是排序前的编号。如果对order
by从句中的字段建立了索引，那么，rownum也是按顺序输出的，因为这时候生成原始的查询结果集时会参照索引表的顺序来构建。

 

sqlserver:sql ="select top 10 * from id not id(select top " + (pageNo-1)*pageSize +"id from articles)"

 

DataSource ds = newInitialContext().lookup(jndiurl);

Connection cn =ds.getConnection();

//"select * fromuser where id=?"  --->binarydirective

PreparedStatementpstmt = cn.prepareSatement(sql);

ResultSet rs =pstmt.executeQuery()

while(rs.next())

{

       out.println(rs.getString(1));

}

 

2.不可滚动的游标

pageSize=20;

pageNo = 5;

cn = null

stmt = null;

rs = null;

try

{

sqlserver:sql ="select  * from articles";

 

DataSource ds = newInitialContext().lookup(jndiurl);

Connection cn =ds.getConnection();

//"select * fromuser where id=?"  --->binarydirective

PreparedStatementpstmt = cn.prepareSatement(sql);

ResultSet rs =pstmt.executeQuery()

for(intj=0;j<(pageNo-1)*pageSize;j++)

{

       rs.next();

}

 

int i=0;

 

while(rs.next()&& i<10)

{

       i++;

       out.println(rs.getString(1));

}

}

cacth(){}

finnaly

{

       if(rs!=null)try{rs.close();}catch(Exceptione){}

       if(stm.........

       if(cn............

}

 

3.可滚动的游标

pageSize=20;

pageNo = 5;

cn = null

stmt = null;

rs = null;

try

{

sqlserver:sql ="select  * from articles";

 

DataSource ds = newInitialContext().lookup(jndiurl);

Connection cn =ds.getConnection();

//"select * fromuser where id=?"  --->binarydirective

PreparedStatementpstmt = cn.prepareSatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,...);

//根据上面这行代码的异常SQLFeatureNotSupportedException，就可判断驱动是否支持可滚动游标

 

ResultSet rs =pstmt.executeQuery()

rs.absolute((pageNo-1)*pageSize)

int i=0;

while(rs.next()&& i<10)

{

       i++;

       out.println(rs.getString(1));

}

}

cacth(){}

finnaly

{

       if(rs!=null)try{rs.close();}catch(Exceptione){}

       if(stm.........

       if(cn............

}