oracle分页
string strSql = "SELECT * FROM (SELECT t1.* ,ROWNUM rn FROM (SELECT * FROM t_crab_base) t1 WHERE Rownum<="+next+") WHERE rn>"+pre;
string strSql = "SELECT * FROM (SELECT t1.* ,ROWNUM rn FROM (SELECT * FROM t_crab_base) t1 WHERE Rownum<="+next+") WHERE rn>"+pre;