$sql = "SELECT * FROM WiFiHotSpots WHERE ItemName = ? AND ItemID > 2";
非變量可以直接寫入資料庫

不過這樣的話，就無法得到生成的SQL字符串了。。。

$address = "Delaware St";

$sql = "SELECT * FROM WiFiHotSpots WHERE ItemName = ? AND ItemID < 15 AND ItemAddress = ?";
$stmt = $dbh->prepare($sql);
$stmt->execute(array($name, $address));
$row = $stmt->fetch();
echo "(" . $row["ItemLatitude"] . ", " . $row["ItemLongitude"] . ")";

判斷記錄集是否為空：
if (!$stmt->rowCount()) {
  echo "記錄集為空";
}

$stmt->rowCount()可以直接當布爾值用。

原始方法：
if (mysql_num_rows($rs) == 0) {
echo "記錄集為空";
}

回復：33樓
http://php.net/manual/en/pdostatement.debugdumpparams.php
debugDumpParams可以用來輸出SQL及其參數，但是無法產生目標SQL。

Error SQL query:

SELECT * FROM WiFiHotSpots WHERE ItemName = ? AND ItemID < 15 AND ItemAddress = ? LIMIT 0, 25
MySQL said:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '? AND ItemID < 15 AND ItemAddress = ?
LIMIT 0, 25' at line 1

bindColumn的用法：
<?php
include_once("conn.php");

$sql = "SELECT * FROM WiFiHotSpots";
$stmt = $dbh->prepare($sql);
$stmt->execute();

$stmt->bindColumn("ItemSuburb", $suburb);
foreach ($stmt as $row) {
    echo $suburb . "<br>";
    // $suburb is equivalent to $row["ItemSuburb"]
}
?>