Mysql File Import Issue When Use CURRENT_TIMESTAMP in column - mysql

Question

I have a table which use CURRENT_TIMESTAMP as a default value on column. table working fine. but when export the database and then again import the exported mysql file, then the CURRENT_TIMESTAMP column replace all date with current today datetime.
This is the table srtructure:
CREATE TABLE a (
id int NOT NULL AUTO_INCREMENT,
col0 varchar(5) NOT NULL ,
col1 varchar(10) NOT NULL,
col2 varchar(20) ,
col3 varchar(20) NOT NULL,
createDateTime timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (id))
ENGINE=InnoDB
AUTO_INCREMENT=7430
DEFAULT CHARSET=utf8
COLLATE=utf8_unicode_ci

Answer 1

Just replace createDateTime timestamp with createDateTime datetime

Answer 2

I can say that the problem is here:
CREATE TABLE a (
id int NOT NULL AUTO_INCREMENT,
col0 varchar(5) NOT NULL ,
col1 varchar(10) NOT NULL,
col2 varchar(20) ,
col3 varchar(20) NOT NULL,
createDateTime timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, <--- **Here
PRIMARY KEY (id))
ENGINE=InnoDB
AUTO_INCREMENT=7430
DEFAULT CHARSET=utf8
COLLATE=utf8_unicode_ci;
Since you define the createDateTime column with CURRENT_TIMESTAMP as default, whenever there's changes on the row data, the column would update itself.
I experienced this once when I was doing an app and I put my createdDate column as CURRENT_TIMESTAMP default similar as you. Then I realize that every time I made changes on some information through the app, the column also get updated to the current timestamp; which ultimately made my data all messed up!
I think what you can do from the exported file (sql dump) is:
Open the dump file using a text editor - (caveat: if the dump file is too large, might not be easy to open.)
Locate the CREATE TABLE syntax in the dump file then change the following:
CREATE TABLE a (
id int NOT NULL AUTO_INCREMENT,
col0 varchar(5) NOT NULL ,
col1 varchar(10) NOT NULL,
col2 varchar(20) ,
col3 varchar(20) NOT NULL,
createDateTime timestamp NOT NULL, <--- **Here
PRIMARY KEY (id))
ENGINE=InnoDB
AUTO_INCREMENT=7430
DEFAULT CHARSET=utf8
COLLATE=utf8_unicode_ci;
Save the dump file and try importing it.
If that doesn't work, I suggest:
Create another table using the CREATE TABLE with modified createDateTime column above - name it as a1 or a_copy etc.
Run INSERT query from table A like :
INSERT INTO a_copy SELECT * FROM a;
Check if data matches between the two table - I usually run a LEFT JOIN query for a quick check like this:
SELECT a.id, a_copy.id FROM a
LEFT JOIN a_copy
ON a.id=a_copy.id
AND a.col0=a_copy.col0
AND a.col1=a_copy.col1
AND a.col2=a_copy.col2
AND a.col3=a_copy.col3
AND a.createDateTime=a_copy.createDateTime
WHERE a_copy.id IS NULL;
*The ON condition can be just ON a.id=a_copy.id AND a.createDateTime=a_copy.createDateTime and WHERE a_copy.id IS NULL is just simply showing any result that doesn't match.
Once you're satisfied, export and import the a_copy table.