af1beb6ce4
Fix: #3946 CL: 1. Add prepare phase for `from_unixtime()`, `date_format()` and `convert_tz()` functions, to handle the format string once for all. 2. Find the cctz timezone when init `runtime state`, so that don't need to find timezone for each rows. 3. Add constant rewrite rule for `utc_timestamp()` 4. Add doc for `to_date()` 5. Comment out the `push_handler_test`, it can not run in DEBUG mode, will be fixed later. 6. Remove `timezone_db.h/cpp` and add `timezone_utils.h/cpp` The performance shows bellow: 11,000,000 rows SQL1: `select count(from_unixtime(k1)) from tbl1;` Before: 8.85s After: 2.85s SQL2: `select count(from_unixtime(k1, '%Y-%m-%d %H:%i:%s')) from tbl1 limit 1;` Before: 10.73s After: 4.85s The date string format seems still slow, we may need a further enhancement about it.
2.0 KiB
2.0 KiB
title, language
| title | language |
|---|---|
| convert_tz | zh-CN |
convert_tz
Syntax
DATETIME CONVERT_TZ(DATETIME dt, VARCHAR from_tz, VARCHAR to_tz)
Description
转换datetime值dt，从 from_tz 由给定转到 to_tz 时区给出的时区，并返回的结果值。 如果参数无效该函数返回NULL。
Example
mysql> select convert_tz('2019-08-01 13:21:03', 'Asia/Shanghai', 'America/Los_Angeles');
+---------------------------------------------------------------------------+
| convert_tz('2019-08-01 13:21:03', 'Asia/Shanghai', 'America/Los_Angeles') |
+---------------------------------------------------------------------------+
| 2019-07-31 22:21:03 |
+---------------------------------------------------------------------------+
mysql> select convert_tz('2019-08-01 13:21:03', '+08:00', 'America/Los_Angeles');
+--------------------------------------------------------------------+
| convert_tz('2019-08-01 13:21:03', '+08:00', 'America/Los_Angeles') |
+--------------------------------------------------------------------+
| 2019-07-31 22:21:03 |
+--------------------------------------------------------------------+
keyword
CONVERT_TZ