Mysql datetime DEFAULT CURRENT_TIMESTAMP error
if you wants to default time to must change to timestamp
in your datatype,
the datetime
is going to display the user input of table...
http://dev.mysql.com/doc/refman/5.0/en/timestamp-initialization.html
http://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.html
As the DEFAULT CURRENT_TIMESTAMP
question is already answered, i will only respond to the case-sensitivity mismatch in table names between windows and linux.
On Windows, file systems are by default case-insensitive.
But on Linux and other *NIX like Operating Systems, they are case-sensitive by default.
The reason why you get a mismatch in behaviour here is the file system, as each table is created as a separate file and the filesystem handles case-sensitivity for you.
MySQL has a parameter to override this behaviour:
For example, on Unix, you can have two different tables named
my_table
andMY_TABLE
, but on Windows these two names are considered identical. To avoid data transfer problems arising from lettercase of database or table names, you have two options:
Use
lower_case_table_names=1
on all systems. The main disadvantage with this is that when you useSHOW TABLES
orSHOW DATABASES
, you do not see the names in their original lettercase.Use
lower_case_table_names=0
on Unix andlower_case_table_names=2
on Windows. This preserves the lettercase of database and table names. The disadvantage of this is that you must ensure that your statements always refer to your database and table names with the correct lettercase on Windows. If you transfer your statements to Unix, where lettercase is significant, they do not work if the lettercase is incorrect.
Exception: If you are using InnoDB tables and you are trying to avoid these data transfer problems, you should setlower_case_table_names=1
on all platforms to force names to be converted to lowercase.[...]
To avoid problems caused by such differences, it is best to adopt a consistent convention, such as always creating and referring to databases and tables using lowercase names. This convention is recommended for maximum portability and ease of use.
This is an excerpt from the MySQL manual on the case sensitivity of identifiers
The DEFAULT CURRENT_TIMESTAMP
support for a DATETIME
(datatype) was added in MySQL 5.6.
In 5.5 and earlier versions, this applied only to TIMESTAMP
(datatype) columns.
It is possible to use a BEFORE INSERT
trigger in 5.5 to assign a default value to a column.
DELIMITER $$
CREATE TRIGGER ...
BEFORE INSERT ON mytable
FOR EACH ROW
BEGIN
IF NEW.mycol IS NULL THEN
SET NEW.mycol = NOW();
END IF;
END$$
Case sensitivity (of queries against values stored in columns) is due to the collation
used for the column. Collations ending in _ci
are case insensitive. For example latin1_swedish_ci
is case insensitive, but latin1_general_cs
is case sensitive.
The output from SHOW CREATE TABLE foo
will show the character set and collation for the character type columns. This is specified at a per-column level. The "default" specified at the table level applies to new columns added to the table when the new column definition doesn't specify a characterset.
UPDATE
Kaii pointed out that my answer regarding "case sensitivity" deals with values stored within columns, and whether queries will return a value from a column containing a value of "New"
will be returned with a predicate like "t.col = 'new'"
.
See Kaii's answer regarding identifiers (e.g. table names) being handled differently (by default) on Windows than on Linux.