更新表，如果不存在则添加数据

Question

I am trying to update table and add data if it doesnt exist in the table row.

$data = "red flowers";
$id = "12";

mysql_query("update shares set data = data + '".$data."'  WHERE id = '".$id."' LIMIT 1") 

But it doesnt work. What is the correct way to do it ?

Answer 1

Use the REPLACE statement instead of UPDATE. It works exactly the same as a INSERT statement, but it will replace the data if data with the same primary keys exists.

Ex: mysqli_query("REPLACE INTO shares (id,data) values (".$id.",'".$data."')");

You should sanitize your data to avoid SQL Injection. You need DELETE privileges for this statement to work