SqlServer存储过程转换成Oracle储存过程语法常见问题

同级情况下的优先处理顺序：
sqlserver: 先order by 再top
oracle:    先rownum 再 order by

alter table css_sed rename column action to myaction;

alter table css_sed add (action varchar2(20));

update css_sed set action = myaction;

alter table css_sed drop column myaction;

isnull(cast(cast(GR_WT as int) as varchar),'') sqlserver

nvl(cast(trunc(cntr_row.GR_WT) as varchar2),'') plsql

oracle 没有这个语法
解决方法： 拿一个临时变量储存结果来判断
begin
select count(*) into V_CNT from all_tables where table_name = 'CUST_BC_ONLINE';
if(V_CNT > 0)
then
execute immediate 'truncate table CUST_BC_ONLINE';
end if;
end;

Oracle: 使用index hints实现  eg: select /*+ index(t i_t) */ * from t where use
b29b
rname='EYGLE';

isnull(MCS_SHPT_INFO.LAST_MOD_DT,0) < b.LAST_MOD_DT

nvl(MCS_SHPT_INFO.LAST_MOD_DT,to_date('1900-01-01','yyyy-mm-dd'))) < b.LAST_MOD_DT

select top(5) @param = column from table
sqlserver默认会把最后一条数据的字段赋值给指定参数，oracle会报错，就是选择出来的行数不匹配。

oracle: null跟字符串拼接,会把null当成空字符串处理
sqlserver: null跟字符串拼接,会把整个字符串设置为一个空格

dbms_output.put_line(dbms_utility.format_error_stack());
dbms_output.put_line('----------------------------------------------------------------');
dbms_output.put_line(dbms_utility.format_call_stack());
dbms_output.put_line('----------------------------------------------------------------');
dbms_output.put_line(dbms_utility.format_error_backtrace());
dbms_output.put_line('----------------------------------------------------------------');
dbms_output.put_line(sqlcode);
dbms_output.put_line(sqlerrm);

SqlServer:
select into table2 from table1
备注：table2可以不存在
Oracle:
insert into table2 select * from table1
备注：要求table2必须存在