access oracle sqlserver 实现同一功能的不同函数

if ("ACC".equals(CONFIG.DBCONN2)  ) {

sql.append("IIF(STATE ='0','未读',IIF(STATE ='1','已读',STATE)) AS   STATEMENT ");

} else if ("ORA".equals(CONFIG.DBCONN2)) {

sql.append("DECODE(STATE ,'0','未读',DECODE(STATE ,'1','已读',STATE)) AS STATEMENT ");

} else if("SQL".equals(CONFIG.DBCONN2)){

sql.append("(CASE WHEN STATE ='0' THEN '未读' WHEN STATE ='1' THEN '已读' END) AS STATEMENT ");

}



if ("ACC".equals(CONFIG.DBCONN2)  ) {

sql.append("', MODIFYDATE=datevalue(now) +timevalue(now) ");

} else if ("ORA".equals(CONFIG.DBCONN2)) {

sql.append("', MODIFYDATE=sysdate ");

} else if("SQL".equals(CONFIG.DBCONN2)){

sql.append("', MODIFYDATE=getdate() ");
}


if ("ACC".equals(CONFIG.DBCONN2) ) {
sql = "DELETE FROM " + tablename + "where datediff('d',now,"
+ dateField + ")>90";

} else if ("ORA".equals(CONFIG.DBCONN2)) {
         sql = "DELETE FROM " + tablename + "where to_date("+ dateField + ",'YYYY-MM-DD HH24:MI:SS') >sysdate - 90";

} else if("SQL".equals(CONFIG.DBCONN2)){

         sql = "DELETE FROM " + tablename + "where datediff('d',"+ dateField + ",getdate())>90";

}


检索数据库中所有表的个数：


   SQL server  ：select name from sysobjects where xType = 'U'
   ORACLE:      select * from user_all_tables