Can I Iterate Through a MySQL Result Set Twice Using mysql_* Functions?

Iterating through a MySQL Result Set Twice with mysql_* Functions

When working with MySQL result sets using the mysql_* functions, a common question arises - can one loop through the same result set multiple times?

Typically, passing a MySQL query to mysql_query yields a result set, which is traversed using mysql_fetch_assoc to access individual rows as associative arrays. By default, after the result set has been fully traversed, the pointer reaches the end, making it impossible to loop through the results again.

However, there exists a workaround to reset the pointer and loop through the result set repeatedly.

To achieve this:

$result = mysql_query(/* Your query */);
while($row = mysql_fetch_assoc($result)){
    // Process the row here...
}

// Reset the pointer to the beginning
mysql_data_seek($result, 0);
while($row = mysql_fetch_assoc($result)){
    // Process the row again...
}

By moving the pointer back to the beginning with mysql_data_seek(0), it is possible to traverse the same result set multiple times.

However, it's worth noting that this practice is generally discouraged. It's considered inefficient and error-prone compared to performing all necessary processing within a single iteration of the result set.

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