database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-15751 CURRENT_TIMESTAMP should return a TIMESTAMP [WITH TIME ZONE?]

Browse Source 
Changing the return type of the following functions:
  - CURRENT_TIMESTAMP, CURRENT_TIMESTAMP(), NOW()
  - SYSDATE()
  - FROM_UNIXTIME()
from DATETIME to TIMESTAMP.

Note, the old function NOW() returning DATETIME is still available
as LOCALTIMESTAMP or LOCALTIMESTAMP(), e.g.:

  SELECT
    LOCALTIMESTAMP,     -- DATETIME
    CURRENT_TIMESTAMP;  -- TIMESTAMP

The change in the functions return data type fixes some problems
that occurred near a DST change:

- Problem #1

INSERT INTO t1 (timestamp_field) VALUES (CURRENT_TIMESTAMP);
INSERT INTO t1 (timestamp_field) VALUES (COALESCE(CURRENT_TIMESTAMP));

could result into two different values inserted.

- Problem #2

INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526));
INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526+3600));

could result into two equal TIMESTAMP values near a DST change.

Additional changes:

- FROM_UNIXTIME(0) now returns SQL NULL instead of '1970-01-01 00:00:00'
  (assuming time_zone='+00:00')

- UNIX_TIMESTAMP('1970-01-01 00:00:00') now returns SQL NULL instead of 0
  (assuming time_zone='+00:00'

These additional changes are needed for consistency with TIMESTAMP fields,
which cannot store '1970-01-01 00:00:00 +00:00'
This commit is contained in:
Alexander Barkov
2024-08-26 13:24:59 +04:00
committed by Sergei Golubchik
parent 128fc34990
commit dfaf7e2eb4
31 changed files with 770 additions and 185 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
sql/sql_type.h
View File

@ -1340,7 +1340,7 @@ public:
{
return is_valid_temporal() ? TIME_to_double(this) : 0;
}
my_decimal *to_decimal(my_decimal *to)
my_decimal *to_decimal(my_decimal *to) const
{
return is_valid_temporal() ? Temporal::to_decimal(to) : bad_to_decimal(to);
}
@ -1987,7 +1987,7 @@ public:
str->length(my_time_to_str(this, const_cast<char*>(str->ptr()), dec));
return str;
}
my_decimal *to_decimal(my_decimal *to)
my_decimal *to_decimal(my_decimal *to) const
{
return is_valid_time() ? Temporal::to_decimal(to) : bad_to_decimal(to);
}
@ -2342,7 +2342,7 @@ public:
str->length(my_date_to_str(this, const_cast<char*>(str->ptr())));
return str;
}
my_decimal *to_decimal(my_decimal *to)
my_decimal *to_decimal(my_decimal *to) const
{
return is_valid_date() ? Temporal::to_decimal(to) : bad_to_decimal(to);
}
@ -2663,7 +2663,7 @@ public:
str->length(my_datetime_to_str(this, const_cast<char*>(str->ptr()), dec));
return str;
}
my_decimal *to_decimal(my_decimal *to)
my_decimal *to_decimal(my_decimal *to) const
{
return is_valid_datetime() ? Temporal::to_decimal(to) : bad_to_decimal(to);
}