这个MySQL查询语法有什么问题？

Question

$db = mysql_select_db("remote"); 

if(!$db) {
    die("Unable to select database");
} 

$query = "SET @cumulative_sum := 0; 
          SELECT timestamp, 
                 @cumulative_sum := @cumulative_sum + value AS cumulative_sum 
          FROM remote.historical 
          WHERE timestamp>= CURDATE()"; 

$result = mysql_query($qry);

When I use this query in my HeidiSQL, it output okay...running cumulative over current day, but when I copied this code into php file, web browser outputs:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT timestamp, @cumulative_sum := @cumulative_sum + value AS cumulative_sum F' at line 1

What is wrong with this code?

Answer 1

Instead of executing two statements, you can alternative declare the variable in a subquery, eg.

SELECT  timestamp, 
        @cumulative_sum := @cumulative_sum + value AS cumulative_sum 
FROM    remote.historical, (SELECT @cumulative_sum := 0) b
WHERE timestamp>= CURDATE()

Answer 2

For security reasons query() function do not allow multiple queries in the single statement but you can do this using mysqli_multi_query() .

The following link will help you: Multiple queries in single PHP query statement