How to convert html entities to utf-8 when upload to database? PHP

Question

I upload a symbol '<' to database getting the symbol from a <div value = '<'> . And when I watch the database result, there displayed a html entity < . And I tried html_entity_decode() , but it doesn't work.

Here is my code div:

<option value = "<"   <?php if ( ! empty ( $dwwp_stored_meta['operator-post'] ) ) {
if ( $dwwp_stored_meta['operator-post'][0]== '<' )
    echo 'selected = "selected"';
} ?>> < </option>

And here is the update function:

update_post_meta( $post_id, 'operator', sanitize_text_field(html_entity_decode($_POST[ 'operator' ],ENT_QUOTES,"UTF-8" )));

But the function upload a html entity, how can I solve it? thx a lot.

Answer 1

sanitize_text_field says: "Converts single < characters to entities"

So, just don't use that function. It has nothing to do with SQL anyway - it is meant for outputting to a HTML text field, not for SQL text fields.

Answer 2

Use built in PHP utf8-encode function.

http://php.net/manual/en/function.utf8-encode.php