如何更新WordPress数据

Question

I am now making a BD police law exam , I want to add exam counting system but my code not working properly, I'm Mysql beginner.

$charset_collate = $wpdb->get_charset_collate();
$variable211 = $wpdb->prefix . "exam_count";        
$variable2111 = "CREATE TABLE IF NOT EXISTS $variable211 (
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    countt DOUBLE NOT NULL
) $charset_collate;";
require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
dbDelta( $variable2111 );

This my code:

$myrows1 = $wpdb->get_results( "SELECT * FROM $variable211 WHERE id=1" );
$count=$myrows1->countt;
$count=$count+1;
if(!$myrows1){
    $sql1 = $wpdb->query( $wpdb->prepare( "INSERT INTO $variable211 ( countt) VALUES ( %f ) ",1));
}else{
    $sql2= $wpdb->query( $wpdb->prepare( "UPDATE INTO SELECT * FROM $variable211 WHERE ID = 1 ( countt ) VALUES ( %f )",$count));               
}`

Answer 1

Your code will be like below ,

global $wpdb;
$myrows1 = $wpdb->get_results( "SELECT * FROM $variable211 WHERE id=1" );
$count=$myrows1->countt;
$count=$count+1;
if(!$myrows1){
    $sql1 = $wpdb->insert(
        $variable211,
        array(
            'countt' => '1'
        ),
        array(  
            '%d'
        )
    );
}
else{
    $sql2 = $wpdb->update(
        $variable211,
        array(
            'countt' => $count
        ),
        array(
            'ID' => '1'
        ),
        array(  
            '%d'
        )
    );
}

Dont forget to add global $wpdb; in start of file.

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