很多更成熟的数据库都支持预处理语句的概念。什么是预处理语句？可以把它看作是想要运行的 SQL 的一种编译过的模板，它可以使用变量参数进行定制。预处理语句可以带来两大好处：
预处理语句如此有用，以至于它们唯一的特性是在驱动程序不支持的时PDO 将模拟处理。这样可以确保不管数据库是否具有这样的功能，都可以确保应用程序可以用相同的数据访问模式。
示例 #1 用预处理语句进行重复插入
下面例子通过用 name 和 value 替代相应的命名占位符来执行一个插入查询
<?php
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (:name, :value)");
$stmt->bindParam(':name', $name);
$stmt->bindParam(':value', $value);
// 插入一行
$name = 'one';
$value = 1;
$stmt->execute();
// 用不同的值插入另一行
$name = 'two';
$value = 2;
$stmt->execute();
?>
示例 #2 用预处理语句进行重复插入
下面例子通过用 name 和 value 取代 ? 占位符的位置来执行一条插入查询。
<?php
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (?, ?)");
$stmt->bindParam(1, $name);
$stmt->bindParam(2, $value);
// 插入一行
$name = 'one';
$value = 1;
$stmt->execute();
// 用不同的值插入另一行
$name = 'two';
$value = 2;
$stmt->execute();
?>
示例 #3 使用预处理语句获取数据
下面例子获取数据基于键值已提供的形式。用户的输入被自动用引号括起来，因此不会有 SQL 注入攻击的危险。
<?php
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name = ?");
$stmt->execute([$_GET['name']]);
foreach ($stmt as $row) {
print_r($row);
}
?>
示例 #4 Calling a stored procedure with an output parameter
如果数据库驱动支持，应用程序还可以绑定输出和输入参数。 输出参数通常用于从存储过程获取值。 输出参数使用起来比输入参数要稍微复杂一些，因为当绑定一个输出参数时，必须知道给定参数的长度。 如果为参数绑定的值大于建议的长度，就会产生一个错误。
<?php
$stmt = $dbh->prepare("CALL sp_returns_string(?)");
$stmt->bindParam(1, $return_value, PDO::PARAM_STR, 4000);
// 调用存储过程
$stmt->execute();
print "procedure returned $return_value\n";
?>
示例 #5 带输入/输出参数调用存储过程
还可以指定同时具有输入和输出值的参数，其语法类似于输出参数。 在下一个例子中，字符串“hello”被传递给存储过程， 当存储过程返回时，hello 被替换为该存储过程返回的值。
<?php
$stmt = $dbh->prepare("CALL sp_takes_string_returns_string(?)");
$value = 'hello';
$stmt->bindParam(1, $value, PDO::PARAM_STR|PDO::PARAM_INPUT_OUTPUT, 4000);
// 调用存储过程
$stmt->execute();
print "procedure returned $value\n";
?>
示例 #6 占位符的无效使用
<?php
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name LIKE '%?%'");
$stmt->execute([$_GET['name']]);
// 占位符必须被用在整个值的位置
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name LIKE ?");
$stmt->execute(["%$_GET[name]%"]);
?>Note that when using name parameters with bindParam, the name itself, cannot contain a dash '-'.
example:
<?php
$stmt = $dbh->prepare ("INSERT INTO user (firstname, surname) VALUES (:f-name, :s-name)");
$stmt -> bindParam(':f-name', 'John');
$stmt -> bindParam(':s-name', 'Smith');
$stmt -> execute();
?>
The dashes in 'f-name' and 's-name' should be replaced with an underscore or no dash at all.
See http://bugs.php.net/43130
AdamInsert a multidimensional array into the database through a prepared query:
We have an array to write the form:
$dataArr:
Array
(
[0] => Array
(
[0] => 2020
[1] => 23
[2] => 111111
)
[1] => Array
(
[0] => 2020
[1] => 24
[2] => 222222222
)
....
Task: prepare a request and pass through binds
$array = [];
foreach ($dataArr as $k=>$v) {
// $x = 2020, the variable is predetermined in advance, does not change the essence
$array[] = [$x, $k, $v];
}
$sql = ("INSERT INTO `table` (`field`,`field`,`field`) VALUES (?,?,?)");
$db->queryBindInsert($sql,$array);
public function queryBindInsert($sql,$bind) {
$stmt = $this->pdo->prepare($sql);
if(count($bind)) {
foreach($bind as $param => $value) {
$c = 1;
for ($i=0; $i<count($value); $i++) {
$stmt->bindValue($c++, $value[$i]);
}
$stmt->execute();
}
}
}Example #5 gives an 1414 wenn tried on MariaDB. Use this function to call a stored procedure with the last parameter as INOUT returning a value like a (uu)id or a count;
<?php
/**
* call_sp Call the specified stored procedure with the given parameters.
* The first parameter is the name of the stored procedure.
* The remaining parameters are the (in) parameters to the stored procedure.
* the last (out) parameter should be an int like state or number of affected rows.
*
* @param mixed $sp_name The name of the stored procedure to call.
* @param mixed $params The parameters to pass to the stored procedure.
* @return int The number of affected rows.
*/
function call_sp( \PDO $db, string $sp_name, ...$params ): mixed
{
$placeholders = array_fill( 0, count( $params ), "?" );
$placeholders[] = "@new_id";
$sql = "CALL $sp_name( " . implode( ", ", $placeholders ) . " ); SELECT @new_id AS `new_id`";
try {
LOG->debug( "calling Stored Procedure", [ "sql" => $sql ] );
$stmt = $db->prepare( $sql );
$i = 0;
foreach( $params as $param ) {
$stmt->bindValue( ++$i, $param );
}
$stmt->execute();
$new_id = $stmt->fetch( PDO::FETCH_ASSOC )['new_id'];
return $new_id;
} catch ( \Exception $e ) {
LOG->error( "Error calling Stored Procedure", [ "sql" => $sql, "params" => $params, "error" => $e->getMessage() ] );
throw $e;
}