Why is my data being truncated? Warning | 1265 | Data truncated for column

Question

I tried adding NULL to both date_of_birth and date_of_death, but that didn't help. Why is data being truncated? (especially because there isn't any data at the moment...)

Also, I don't understand warning 1261 at all. Row 5 is no different from rows 1-4.

Thanks!

The following script:

-- create the people table
DROP TABLE IF EXISTS people;

CREATE TABLE people (
full_name varchar (50) NOT NULL,
people_ID varchar (15) NOT NULL,
date_of_birth DATE,
date_of_death DATE,
PRIMARY KEY(people_ID))
ENGINE = INNODB;

LOAD DATA LOCAL INFILE "People.csv"
INTO TABLE people
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n'
IGNORE 1 LINES;  

Gives me these errors:

Query OK, 5 rows affected, 10 warnings (0.00 sec)
Records: 5  Deleted: 0  Skipped: 0  Warnings: 10

mysql> show warnings;
+---------+------+----------------------------------------------------+
| Level   | Code | Message                                            |
+---------+------+----------------------------------------------------+
| Warning | 1265 | Data truncated for column 'date_of_birth' at row 1 |
| Warning | 1265 | Data truncated for column 'date_of_death' at row 1 |
| Warning | 1265 | Data truncated for column 'date_of_birth' at row 2 |
| Warning | 1265 | Data truncated for column 'date_of_death' at row 2 |
| Warning | 1265 | Data truncated for column 'date_of_birth' at row 3 |
| Warning | 1265 | Data truncated for column 'date_of_death' at row 3 |
| Warning | 1265 | Data truncated for column 'date_of_birth' at row 4 |
| Warning | 1265 | Data truncated for column 'date_of_death' at row 4 |
| Warning | 1265 | Data truncated for column 'date_of_birth' at row 5 |
| Warning | 1261 | Row 5 doesn't contain data for all columns         |
+---------+------+----------------------------------------------------+
10 rows in set (0.00 sec)

mysql> select * from people;
+-------------------+-----------+---------------+---------------+
| full_name         | people_ID | date_of_birth | date_of_death |
+-------------------+-----------+---------------+---------------+
| Harry Dunham      | H_Dunham  | 0000-00-00    | NULL          |
| Julien Bryan      | J_Bryan   | 0000-00-00    | 0000-00-00    |
| Jules V.D. Bucher | J_Bucher  | 0000-00-00    | 0000-00-00    |
| Miriam Bucher     | M_Bucher  | 0000-00-00    | 0000-00-00    |
| Paul Bowles       | P_Bowles  | 0000-00-00    | 0000-00-00    |
+-------------------+-----------+---------------+---------------+
5 rows in set (0.01 sec)

Here is my .csv:

FullName,People_ID,DOB,DOD
Jules V.D. Bucher,J_Bucher,,
Miriam Bucher,M_Bucher,,
Julien Bryan,J_Bryan,,
Paul Bowles,P_Bowles,,
Harry Dunham,H_Dunham,,

Answer 1

Perhaps what's happening is that Mysql is trying to force the empty string "" into your date column, but the column only accepts DATE formatted data so it's converted into the proper format. Try adjusting your CSV so one of the rows has "0000-00-00" in the date columns instead of just "" (blank), and see if you get fewer warnings.

The 1261 warning looks like more of same -- probably harmless but annoying quirks in how Mysql handles CSV import -- and I wouldn't worry about it unless you see evidence that your imported data aren't complete.