check if SQL row exists with PHP

user_834730 0
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I'm using MySQL with PHP and I need to do something like this (pseudocode):

if (sql row exists where username='bob')
{
    // do this stuff
}
if-statement mysql sql php
3 Answers

Sayem's answer has the most upvotes, but I believe it is incorrect regarding PDO.

From the PHP docs:

For most databases, PDOStatement::rowCount() does not return the number of rows affected by a SELECT statement. Instead, use PDO::query() to issue a SELECT COUNT(*) statement with the same predicates as your intended SELECT statement, then use PDOStatement::fetchColumn() to retrieve the number of rows that will be returned.

$sql = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
if ($res = $conn->query($sql)) {

  /* Check the number of rows that match the SELECT statement */
  if ($res->fetchColumn() > 0) {

       /* Issue the real SELECT statement and work with the results */
       $sql = "SELECT name FROM fruit WHERE calories > 100";
       foreach ($conn->query($sql) as $row) {
           print "Name: " .  $row['NAME'] . "\n";
       }
  }
  /* No rows matched -- do something else */
  else {
      print "No rows matched the query.";
  }
}

$res = null;
$conn = null;
user_12609300
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