MySQL, how to insert null dates

Question

I am having trouble inserting null values into date fields into a MySQL table.

Here is the insert query:

$query = 'INSERT INTO table (column_s1, column_s2, column_d1, column_d2)
VALUES ("'.$string1.'", "'.$string2.'", '.$date1.', '.$date2.')';

Columns s1 and s2 take string values and d1 and d2 take dates. When I run this query with only the string fields, there is no problem.

The date values can be either set or null, so I have not included the quotation marks in the query, but have instead added them to the variable earlier on. This is the php code I am using to set the date values:

if (empty($date1)){
    $date1 = NULL;
}
else{
    $date1part = explode("/",$date1);
    $date1 = '"'.$date1part[2].'/'.$date1part[1].'/'.$date1part[0].'"';
}

When the date values are all set, the record is inserted correctly. However, when either of the dates is null, nothing is inserted.

Why can't I just insert null values into MySQL like this?

Whats the error message you're getting? Has the database been setup to allow null values? No constraints in place? — null, Jul 22 '13 at 09:50
use cases.. case when $date1 != null then $date1 else null end — zxc, Jul 22 '13 at 09:51
I can't get it to produce any error messages? As far as I can tell, it seems to think it's inserted it. Is there some way you can suggest for debugging? Yes, the database accepts null values. When I use the SQL command space it lets me insert NULL values there, it seems only to be when it's coming from my php. — ajor, Jul 22 '13 at 09:56
Echo out the actual query it is running and post them here when it works and fails so we can see what you are actually sending to the db. PS that code is invalid `if (empty($date1){` = syntax error — Anigel, Jul 22 '13 at 09:57
possible duplicate of [Null value is substituted by ''](http://stackoverflow.com/questions/17717349/null-value-is-substituted-by) — deceze, Jul 22 '13 at 10:04
Ok, so when I restrict the query to just the strings, it works: `INSERT INTO contracts (contractor, title) VALUES ("string1","string2")` When both dates are not null it works: `INSERT INTO contracts (contractor, title, start, end) VALUES ("string1","string2","02/02/02","03/02/02")` Otherwise it does not: `INSERT INTO contracts (contractor, title, start, end) VALUES ("string1","string2","02/02/02",)` `INSERT INTO contracts (contractor, title, start, end) VALUES ("string1","string2",,)` — ajor, Jul 22 '13 at 10:07
@Anigel - sorry that's just a typo here, doesn't exist in my actual code. Edited to change. — ajor, Jul 22 '13 at 10:08
@deceze: thank you for linking to this question. I had already tried that solution (I thought), but obviously in slightly different circumstances as it now appears to have solved my problem. The issue was that it was taking a php null value rather than inputting the null into SQL. Many thanks. — ajor, Jul 22 '13 at 10:17
Try this https://stackoverflow.com/questions/17717349/null-value-is-substituted-by/71557360#71557360 — Himanshu Kumar, Mar 22 '22 at 16:32

Wh1T3h4Ck5 · Answer 1 · 2013-07-22T10:22:56.447

12

Try this:

$query = "INSERT INTO table (column_s1, column_s2, column_d1, column_d2) 
          VALUES ('$string1', '$string2', " . ($date1==NULL ? "NULL" : "'$date1'") . ", " . ($date2==NULL ? "NULL" : "'$date2'") . ");";

so for example if you put this into query:

$string1 = "s1";
$string2 = "s2";
$date1 = NULL;
$date2 = NULL;

result should be:

INSERT INTO table (column_s1, column_s2, column_d1, column_d2) VALUES ('s1', 's2', NULL, NULL);

edited Jul 22 '13 at 10:22

answered Jul 22 '13 at 10:16

Wh1T3h4Ck5

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Thank you, this is the best and smart answer that worked for me – Lenin Zapata Oct 15 '18 at 11:37

score 7 · Answer 2 · edited May 23 '17 at 12:00

You should convert the null variable into a NULL string first Like this:

if(is_null($date1)){
    $date1 = 'NULL';
}

If you are using a MySQL date column, you must also specify that it should hold null when creating it, like this:

CREATE TABLE `table` (
id INT NOT NULL AUTO_INCREMENT,
date DATE NULL DEFAULT NULL,
PRIMARY KEY(id)
)

It is also very important that you perform the query with bound parameters, for example using pdo

Something like this:

$query = 'INSERT INTO table (column_s1, column_s2, column_d1, column_d2)
VALUES (?, ?, ?, ?)';
$stmt = $db->prepare($query);
$stmt->execute(array($string1,$string2,$date1,$date2));

score 3 · Answer 3 · edited Jul 22 '20 at 17:25

3

If NULL does not work, just pass your date as "0000-00-00":

$chequeDate = "0000-00-00";

edited Jul 22 '20 at 17:25

Brhaka

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answered Jun 28 '18 at 05:18

Optimaz Prime

857
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This will throw a warning or an error in MySQL 5.7 or above. zero value dates are no loonger allowed by default and not recommended. – Martin Jul 07 '21 at 22:44

score 2 · Answer 4 · edited Jan 03 '14 at 04:09

2

Backslash N is another way to express NULL in MySQL.

Try putting the value (backslash N): \N into one of the parameters like this:

$data1 = "\N";
$sql="insert into tablename set column_s1='" . $data1 . 
  "', column_s2='" . data2 . 
  "', column_s3='" . $data3 . "'";

Reference: http://dev.mysql.com/doc/refman/5.1/en/load-data.html

edited Jan 03 '14 at 04:09

Eric Leschinski

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answered Jul 22 '13 at 10:13

innovative kundan

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1

NO, that's same as OP query + still doesn't work with NULL values. – Wh1T3h4Ck5 Jul 22 '13 at 10:27

score 1 · Answer 5 · edited Jul 29 '14 at 18:08

1

In Derby, If you want to insert values except the ones you have declared Null (column_d1, column_d2), sql:

INSERT INTO DB.table (column_s1, column_s2) VALUES ('s1', 's2');

edited Jul 29 '14 at 18:08

Philippe Blayo

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answered Jul 29 '14 at 18:03

Luis Daniel Dorta

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score 1 · Answer 6 · answered Feb 04 '15 at 13:33

Probably answer is unneeded at this moment, but I found solution exactly I have been searching. Use an Expression to pass NULL like this:

['some_date_to_update' => new Expression('NULL')]

Hence, MySQL will understand what you want, and save (NULL) in DB instead of storing 0-dates. Hope this will help somebody.

score 0 · Answer 7 · answered Jan 17 '19 at 08:38

0

In Mysql DATE data type Default NULL means

Some version set as 0000-00-00

Some version set as 1970-01-01

answered Jan 17 '19 at 08:38

Siva

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score 0 · Answer 8 · answered May 11 '22 at 11:07

0

Years later, if someone is still experiencing this issue, you want to use PDO and bind the variables, everything will be taken care of no need to handle the null variables yourself.

answered May 11 '22 at 11:07

norbert chitsike

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MySQL, how to insert null dates

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