Oracle 中的from_tz函数,可以将一个timstamp和timzone拼成一个timestamp with timezone
SQL> select from_tz(to_timestamp('20090102','YYYYMMDD'), 'America/Sao_Paulo') from dual;
FROM_TZ(TO_TIMESTAMP('20090102
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02-1月 -09 12.00.00.000000000 上午 AMERICA/SAO_PAULO SQL> select from_tz(to_timestamp('20090102','YYYYMMDD'), 'America/Sao_Paulo') from dual;
FROM_TZ(TO_TIMESTAMP('20090102
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02-1月 -09 12.00.00.000000000 上午 AMERICA/SAO_PAULO
但如果这个timestamp在指定的时区内不存在(比如由于夏令时,时钟往前拨了一个小时),就会抛Exception
SQL> select from_tz(to_timestamp('20091101','YYYYMMDD'), 'America/Sao_Paulo') from dual;
select from_tz(to_timestamp('20091101','YYYYMMDD'), 'America/Sao_Paulo') from dual
ORA-01878: 在日期时间或间隔中没有找到指定的字段 SQL> select from_tz(to_timestamp('20091101','YYYYMMDD'), 'America/Sao_Paulo') from dual;
select from_tz(to_timestamp('20091101','YYYYMMDD'), 'America/Sao_Paulo') from dual
ORA-01878: 在日期时间或间隔中没有找到指定的字段
解决办法嘛,先取出时区的offset,用其构建好timestamp with timezone后再转回指定的时区就好了
SQL> select from_tz(to_timestamp('20091101','YYYYMMDD'), tz_offset('America/Sao_Paulo')) at TIME ZONE 'America/Sao_Paulo' from dual;
FROM_TZ(TO_TIMESTAMP('20091101
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31-10月-09 11.00.00.000000000 下午 AMERICA/SAO_PAULO