我很好奇是否有可能使用PDO将值数组绑定到占位符。这里的用例试图传递一个值数组，以便与IN()条件一起使用。
我希望能够这样做:
<?php
$ids=array(1,2,3,7,8,9);
$db = new PDO(...);
$stmt = $db->prepare(
'SELECT *
FROM table
WHERE id IN(:an_array)'
);
$stmt->bindParam('an_array',$ids);
$stmt->execute();
?>
并让PDO绑定并引用数组中的所有值。
目前我正在做:
<?php
$ids = array(1,2,3,7,8,9);
$db = new PDO(...);
foreach($ids as &$val)
$val=$db->quote($val); //iterate through array and quote
$in = implode(',',$ids); //create comma separated list
$stmt = $db->prepare(
'SELECT *
FROM table
WHERE id IN('.$in.')'
);
$stmt->execute();
?>
这当然是工作，但只是想知道是否有一个内置的解决方案，我错过了?
下面是我的解决方案，基于alan_mm的答案。我还扩展了PDO类:
class Db extends PDO
{
/**
* SELECT ... WHERE fieldName IN (:paramName) workaround
*
* @param array $array
* @param string $prefix
*
* @return string
*/
public function CreateArrayBindParamNames(array $array, $prefix = 'id_')
{
$newparams = [];
foreach ($array as $n => $val)
{
$newparams[] = ":".$prefix.$n;
}
return implode(", ", $newparams);
}
/**
* Bind every array element to the proper named parameter
*
* @param PDOStatement $stmt
* @param array $array
* @param string $prefix
*/
public function BindArrayParam(PDOStatement &$stmt, array $array, $prefix = 'id_')
{
foreach($array as $n => $val)
{
$val = intval($val);
$stmt -> bindParam(":".$prefix.$n, $val, PDO::PARAM_INT);
}
}
}
下面是上面代码的示例用法:
$idList = [1, 2, 3, 4];
$stmt = $this -> db -> prepare("
SELECT
`Name`
FROM
`User`
WHERE
(`ID` IN (".$this -> db -> CreateArrayBindParamNames($idList)."))");
$this -> db -> BindArrayParam($stmt, $idList);
$stmt -> execute();
foreach($stmt as $row)
{
echo $row['Name'];
}
我扩展了PDO，做一些类似stefs建议的事情，从长远来看，这对我来说更容易:
class Array_Capable_PDO extends PDO {
/**
* Both prepare a statement and bind array values to it
* @param string $statement mysql query with colon-prefixed tokens
* @param array $arrays associatve array with string tokens as keys and integer-indexed data arrays as values
* @param array $driver_options see php documention
* @return PDOStatement with given array values already bound
*/
public function prepare_with_arrays($statement, array $arrays, $driver_options = array()) {
$replace_strings = array();
$x = 0;
foreach($arrays as $token => $data) {
// just for testing...
//// tokens should be legit
//assert('is_string($token)');
//assert('$token !== ""');
//// a given token shouldn't appear more than once in the query
//assert('substr_count($statement, $token) === 1');
//// there should be an array of values for each token
//assert('is_array($data)');
//// empty data arrays aren't okay, they're a SQL syntax error
//assert('count($data) > 0');
// replace array tokens with a list of value tokens
$replace_string_pieces = array();
foreach($data as $y => $value) {
//// the data arrays have to be integer-indexed
//assert('is_int($y)');
$replace_string_pieces[] = ":{$x}_{$y}";
}
$replace_strings[] = '('.implode(', ', $replace_string_pieces).')';
$x++;
}
$statement = str_replace(array_keys($arrays), $replace_strings, $statement);
$prepared_statement = $this->prepare($statement, $driver_options);
// bind values to the value tokens
$x = 0;
foreach($arrays as $token => $data) {
foreach($data as $y => $value) {
$prepared_statement->bindValue(":{$x}_{$y}", $value);
}
$x++;
}
return $prepared_statement;
}
}
你可以这样使用它:
$db_link = new Array_Capable_PDO($dsn, $username, $password);
$query = '
SELECT *
FROM test
WHERE field1 IN :array1
OR field2 IN :array2
OR field3 = :value
';
$pdo_query = $db_link->prepare_with_arrays(
$query,
array(
':array1' => array(1,2,3),
':array2' => array(7,8,9)
)
);
$pdo_query->bindValue(':value', '10');
$pdo_query->execute();
以下是我的解决方案:
$total_items = count($array_of_items);
$question_marks = array_fill(0, $total_items, '?');
$sql = 'SELECT * FROM foo WHERE bar IN (' . implode(',', $question_marks ). ')';
$stmt = $dbh->prepare($sql);
$stmt->execute(array_values($array_of_items));
注意array_values的使用。这可以修复键排序问题。
我正在合并id数组，然后删除重复的项。我是这样写的:
$ids = array(0 => 23, 1 => 47, 3 => 17);
那就是失败。
为了让答案更接近最初使用占位符绑定参数的问题，我做了一些进一步的处理。
这个答案必须在查询中使用的数组中进行两次循环。但它确实解决了为更有选择性的查询使用其他列占位符的问题。
//builds placeholders to insert in IN()
foreach($array as $key=>$value) {
$in_query = $in_query . ' :val_' . $key . ', ';
}
//gets rid of trailing comma and space
$in_query = substr($in_query, 0, -2);
$stmt = $db->prepare(
"SELECT *
WHERE id IN($in_query)";
//pind params for your placeholders.
foreach ($array as $key=>$value) {
$stmt->bindParam(":val_" . $key, $array[$key])
}
$stmt->execute();
