I’m developing a WordPress plugin that needs to handle database operations. The plugin should first check whether a specific record exists in a MySQL table. When the record doesn’t exist, it should create a new entry, which is working perfectly.
The problem occurs when trying to modify an existing record. The modification operation fails completely and I can’t figure out why.
Here’s my current approach:
$wpdb->query($wpdb->prepare("UPDATE $table_name SET timestamp=$current_time WHERE user_id=$user_id"));
I’ve verified that all variables contain valid data since they work fine during record creation. The issue seems to be specifically with the update functionality.
What’s the proper method to handle record updates in WordPress? Am I missing something in my query structure?
Yeah, it’s definitely the prepared statement causing issues, but there’s more to check. Fix the placeholder syntax like others said, but also look at what your update operation actually returns. WordPress $wpdb->query() gives you the number of affected rows - if you get 0, your WHERE condition isn’t matching anything. I hit this exact problem when user_id was stored as a string but I expected an integer. Try $wpdb->get_results() first to confirm the record exists before updating. The $wpdb->update() method is good advice, and don’t forget $wpdb->last_error when things break - it’ll show table structure or permission issues you might miss otherwise.
You’re missing placeholders in your prepare statement. $wpdb->prepare() needs %s for strings and %d for integers - you can’t just stick variables directly into the SQL string. Here’s the fix: php $wpdb->query($wpdb->prepare("UPDATE $table_name SET timestamp=%s WHERE user_id=%d", $current_time, $user_id)); Better yet, use $wpdb->update() instead: php $wpdb->update($table_name, array('timestamp' => $current_time), array('user_id' => $user_id)); This handles sanitization automatically and prevents SQL injection. I’ve used this method in tons of plugins - way more reliable than raw SQL.
for sure, you gotta wrap your vars in quotes when using prepare. try $wpdb->query($wpdb->prepare("UPDATE $table_name SET timestamp='%s' WHERE user_id=%d", $current_time, $user_id)); - that should sort out your update issue.