get_post_meta() is returning arrays even when the $single value is true

[titodevera]

get_post_meta call:

$post_meta = get_post_meta( $post_id, '', true );

Result:

array(
'post_meta_1' => array('post_meta_1_value'),
'post_meta_2' => array('post_meta_2_value')
)

Expected result

array(
'post_meta_1' => 'post_meta_1_value',
'post_meta_2' => 'post_meta_2_value'
)

[dd32]

Hey @titodevera and welcome to Trac!

Can you check your database directly to see if the metadata for the post is what you expect?

Testing it, it seems to be working as expected for me:

var_dump( get_post_meta( 1789, 'name', true ) );
var_dump( get_post_meta( 1789, 'name', false ) );

results in:

string 'one' (length=3)
array (size=2)
  0 => string 'one' (length=3)
  1 => string 'two' (length=3)

Note, that if you have stored an array in the meta value, it'll return that array as the "single" key - WordPress supports multiple meta_values for any given meta_key.

[titodevera]

Hi dd32.

I´m updating meta data as single value and there are no multiple meta_values for any given meta_key.

The error only occurs when i retrieve all post meta data from a post, it´s working well when I specify a meta_key as in your example (second get_post_meta() param)

Thanks!

[chetan200891]

Hi @titodevera welcome to trac!

I have tested same thing in both cases.

First

get_post_meta('ID', 'meta_key', true)

and

get_post_meta('ID', '', true)

. I am getting correct result in both. So I guess as @dd32 mentioned it should be an array value in meta key. May be before you added update_post_meta.

[dd32]

Replying to titodevera:

The error only occurs when i retrieve all post meta data from a post, it's working well when I specify a meta_key as in your example (second get_post_meta() param)

My apologies! I missed that.

In that case, It's intentional, and it looks like the documentation needs updating. The function is a wrapper for ​get_metadata() which does correctly document it.

If someone wants to whip up a patch to update the function docs here that'd be great :)

[chetan200891]

Created patch to change documentation for $single in get_post_meta() function.

[chetan200891]

@dd32

I have created 42687.patch to change documentation for $single in get_post_meta() function. I hope that will be helpful.

[dd32]

In 42227:

Docs: Update the documentation for get_post_meta() to clarify that $single has no effect when the $meta_key is not provided.

Props chetan200891, titodevera.
Fixes #42687.