Question

I have seen this several times. I have one server that allows me to insert some of the values, without specifying the others like so: INSERT INTO table SET value_a='a', value_b='b'; (value_c is a field that does not have a default value set, but it works fine here). When the script is moved to a new server some INSERT queries break because it requires the query to specify all non-default values, giving me the following error for the first occurrence of not specifying a non-default value:

#1364 - Field 'value_c' doesn't have a default value

Setting default values for the table might break functionality in other areas, otherwise I would just do that. I would love to know what exactly is going on here.

Answer 1

One of your servers is running in strict mode by default and the other not.
If a server runs in strict mode (or you set it in your connection) and you try to insert a NULL value into a column defined as NOT NULL you will get #1364 error. Without strict mode your NULL value will be replaced with empty string or 0.

Example:

CREATE TABLE `test_tbl` (
 `id` int(11) NOT NULL,
 `someint` int(11) NOT NULL,
 `sometext` varchar(255) NOT NULL,
 `somedate` datetime NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

SET sql_mode = '';
INSERT INTO test_tbl(id) VALUES(1);
SELECT * FROM test_tbl;
+----+---------+----------+---------------------+
| id | someint | sometext | somedate            |
+----+---------+----------+---------------------+
|  1 |       0 |          | 0000-00-00 00:00:00 |
+----+---------+----------+---------------------+
SET sql_mode = 'STRICT_ALL_TABLES';
INSERT INTO test_tbl(id) VALUES(2);
#1364 - Field 'someint' doesn't have a default value