mysql - add_post_meta does not respect the content

admin管理员组

文章数量:1306985

I insert this and it works fine:

add_post_meta( get_the_ID(), 'robots', 'TEXT', true );

After adding that, I check the database and everything is fine, the result is TEXT.

But if I insert this:

add_post_meta( get_the_ID(), 'robots', 'a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}', true );

The result is:

s:43:"a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}";

And I need the result to be exactly the same as I have added it:

a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}

I need not to automatically add that s:43:" and the "; at the end.

Can anybody help me please?

I insert this and it works fine:

add_post_meta( get_the_ID(), 'robots', 'TEXT', true );

After adding that, I check the database and everything is fine, the result is TEXT.

But if I insert this:

add_post_meta( get_the_ID(), 'robots', 'a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}', true );

The result is:

s:43:"a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}";

And I need the result to be exactly the same as I have added it:

a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}

I need not to automatically add that s:43:" and the "; at the end.

Can anybody help me please?

• mysql

Share Improve this question edited Jan 26, 2021 at 0:36 Sally CJ 40.1k22 gold badges2828 silver badges4949 bronze badges asked Jan 25, 2021 at 23:36 Carlos BCarlos B 1333 bronze badges 3

• 1 I have solved it using unserialize(). Example: add_post_meta( get_the_ID(), 'robots', unserialize('a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}'), true ); – Carlos B Commented Jan 26, 2021 at 0:15
• Does my revised answer answer your question? If so, I'd appreciate if you can mark my answer as "correct" - that way, it'll be clear to others that the question has an accepted solution. Or maybe, just +1 (upvote) my answer? :) – Sally CJ Commented Jan 27, 2021 at 3:35
• 1 Sorry @SallyCJ I don't have much experience in stackexchange, but I have already marked your answer as correct :) Best regards. – Carlos B Commented Jan 27, 2021 at 16:45

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 1

Why the content is not being respected

And it's not just add_post_meta(), but any functions like add_term_meta() and add_user_meta() that uses add_metadata().

And the reason why the value gets serialized again is because add_metadata() will automatically serialize the meta value using maybe_serialize() which (unfortunately) will serialize the value even if it's already serialized.

How to tackle the issue

In your case, if possible, pass an array instead of the serialized value/string:

// A non-scalar value will be automatically serialized by maybe_serialize().
$value = array( 'noindex', 'nofollow' );

add_post_meta( get_the_ID(), 'robots', $value, true );

However, if you retrieved/received the value from somewhere and you need to retain its exact format when saving, then — as you've already figured it out — you'll need to unserialize the value before passing it to add_post_meta() to prevent the double serialization.

But in WordPress, instead of using the native unserialize() function in PHP, I suggest you to use maybe_unserialize() instead:

$value = 'a:2:{i:0;s:7:"noindex";i:1;s:8:"nofollow";}';

// Unserialize the value and pass it to add_post_meta().
add_post_meta( get_the_ID(), 'robots', maybe_unserialize( $value ), true );

本文标签： mysqladdpostmeta does not respect the content