I need to query all posts using SQL (tried doing it with WP_Query didn't work correctly), of certain post types

$post_types = get_post_types(); 
unset( $post_types['attachment'], $post_types['nav_menu_item'] );

$post_type_string = '\'' . implode( '\', \'', $post_types ) . '\'';

global $wpdb;
$replace_query = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE post_type IN ( %s )", $post_type_string ), ARRAY_A );

The $post_types array will give me

array( 'post' => 'post', 'page' => 'page', 'revision' => 'revision', 'custom_css' => 'custom_css', 'attachment' => 'attachment', 'nav_menu_item'=> 'nav_menu_item', 'customize_changeset' => 'customize_changeset', 'tt_font_control' => 'tt_font_control' )

I imploded this array, to add quotes around the values, and put this in my $wpdb->prepare as shown, but all I got was empty array.

When I removed the prepare and did this

$replace_query = $wpdb->get_results( "SELECT * FROM $wpdb->posts WHERE post_type IN ( $post_type_string )", ARRAY_A );

The query worked and I got back full array.

Why did this happen?

The $post_type_string is a string, so %s is correct in the prepare.

I tried not 'quoting' the values in the string, but that didn't work as well, and I tried with double quotes. I know that prepare does

$query = str_replace( "'%s'", '%s', $query ); // in case someone mistakenly already singlequoted it
$query = str_replace( '"%s"', '%s', $query ); // doublequote unquoting
$query = preg_replace( '|(?<!%)%f|' , '%F', $query ); // Force floats to be locale unaware
$query = preg_replace( '|(?<!%)%s|', "'%s'", $query ); // quote the strings, avoiding escaped strings like %%s
array_walk( $args, array( $this, 'escape_by_ref' ) );
return @vsprintf( $query, $args );


from developers prepare docs. Does this happen because of the quotes? And if so, how to prepare my query correctly?


The WP_Query that doesn't work as expected

$temp_posts = new WP_Query( array(
            'post_type' => $post_types,
            'posts_per_page' => 1000000,
            'no_found_rows' => true,
            'post_status' => array( 'any', 'draft' )
  • When a function, method or code snippet doesn't work as you expect, you sould explain what you expected, what you get and the errors you get, if any; "it doesn't work" says nothing about the problem you may have. Can you explain what exactly "WP_Query didn't work correctly" means?
    – cybmeta
    Feb 10, 2017 at 15:11
  • For some reason it won't fetch all post types, only posts. That's why I used a direct query. Trust me I error logged every single combination before posting this :)
    – dingo_d
    Feb 10, 2017 at 15:14
  • WP_Query works with any post type; if you get only posts of standard post type, then you may be passing wrong data. Can you share your WP_Query snippet?
    – cybmeta
    Feb 10, 2017 at 15:16
  • $temp_posts = new WP_Query( array( 'post_type' => $post_types, 'posts_per_page' => 1000000, 'no_found_rows' => true, 'post_status' => array( 'any', 'draft' ) ) ); I didn't use 'posts_per_page' => -1 because that slows the query significantly, and I needed a high number. I tried removing the no_found_rows, that did nothing, and I wanted to query everything in the array of post types.
    – dingo_d
    Feb 10, 2017 at 15:21
  • Please, add the code to the question. Reading large code snipeets in comments is very difficult. Anyway, that WP_Query works perfectly here.
    – cybmeta
    Feb 10, 2017 at 15:25

1 Answer 1


You can use the array directly because the $wpdb->prepare() method can be called like vsprintf(), which works like sprintf() but accepts arrays of arguments.

$post_types = get_post_types(); 
unset( $post_types['attachment'], $post_types['nav_menu_item'] );

global $wpdb;
$replace_query = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE post_type IN ( %s )", $post_types ), ARRAY_A );

The problem with your code is that you get a string like this one:

"'page', 'attachment', 'revision', 'custom_css', 'customize_changeset'"

So, the IN statement you get is like:

IN ( "'page', 'attachment', 'revision', 'custom_css', 'customize_changeset'" )

Instead of the correct one that would be an array of strings:

IN ( 'page', 'attachment', 'revision', 'custom_css', 'customize_changeset' )
  • Really? Because it works as a string without preparing. I didn't try with array tbh
    – dingo_d
    Feb 10, 2017 at 15:09
  • Answer updated to explain why you can use the array and how to convert it to string if you want.
    – cybmeta
    Feb 10, 2017 at 15:39

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