php bindParam 和 bindValue 有什么区别？

What is the difference between bindParam and bindValue?

提问by koen

What is the difference between PDOStatement::bindParam()and PDOStatement::bindValue()?

PDOStatement::bindParam()和 和有PDOStatement::bindValue()什么区别？

采纳答案by acrosman

The answer is in the documentation for bindParam:

答案在以下文档中bindParam：

Unlike PDOStatement::bindValue(), the variable is bound as a reference and will only be evaluated at the time that PDOStatement::execute() is called.

与 PDOStatement::bindValue() 不同，该变量被绑定为一个引用，并且只会在 PDOStatement::execute() 被调用时被评估。

And execute

和 execute

call PDOStatement::bindParam() to bind PHP variables to the parameter markers: bound variables pass their value as input and receive the output value, if any, of their associated parameter markers

调用 PDOStatement::bindParam() 将 PHP 变量绑定到参数标记：绑定变量将它们的值作为输入传递并接收其关联参数标记的输出值（如果有）

Example:

例子：

$value = 'foo';
$s = $dbh->prepare('SELECT name FROM bar WHERE baz = :baz');
$s->bindParam(':baz', $value); // use bindParam to bind the variable
$value = 'foobarbaz';
$s->execute(); // executed with WHERE baz = 'foobarbaz'

or

或者

$value = 'foo';
$s = $dbh->prepare('SELECT name FROM bar WHERE baz = :baz');
$s->bindValue(':baz', $value); // use bindValue to bind the variable's value
$value = 'foobarbaz';
$s->execute(); // executed with WHERE baz = 'foo'

回答by lonesomeday

From the manual entry for PDOStatement::bindParam:

从手册条目中PDOStatement::bindParam：

[With bindParam] Unlike PDOStatement::bindValue(), the variable is bound as a reference and will only be evaluated at the time that PDOStatement::execute()is called.

[With bindParam] 与 不同PDOStatement::bindValue()，变量被绑定为一个引用，并且只会在PDOStatement::execute()被调用的时候被评估。

So, for example:

因此，例如：

$sex = 'male';
$s = $dbh->prepare('SELECT name FROM students WHERE sex = :sex');
$s->bindParam(':sex', $sex); // use bindParam to bind the variable
$sex = 'female';
$s->execute(); // executed with WHERE sex = 'female'

or

或者

$sex = 'male';
$s = $dbh->prepare('SELECT name FROM students WHERE sex = :sex');
$s->bindValue(':sex', $sex); // use bindValue to bind the variable's value
$sex = 'female';
$s->execute(); // executed with WHERE sex = 'male'

回答by Pascal MARTIN

Here are some I can think about :

以下是我能想到的一些：

• With bindParam, you can only pass variables ; not values
• with bindValue, you can pass both (values, obviously, and variables)
• bindParamworks only with variables because it allows parameters to be given as input/output, by "reference" (and a value is not a valid "reference" in PHP): it is useful with drivers that (quoting the manual) :

• 使用bindParam，您只能传递变量；不是价值观
• 有bindValue，你可以通过这两个（值，很明显，和变量）
• bindParam仅适用于变量，因为它允许通过“引用” （并且值在 PHP 中不是有效的“引用”）作为输入/输出给出参数：它对驱动程序很有用（引用手册）：

support the invocation of stored procedures that return data as output parameters, and some also as input/output parameters that both send in data and are updated to receive it.

支持调用存储过程，将数据作为输出参数返回，有些还作为输入/输出参数，既发送数据又更新接收数据。

With some DB engines, stored procedures can have parameters that can be used for both input (giving a value from PHP to the procedure) and ouput (returning a value from the stored proc to PHP) ; to bind those parameters, you've got to use bindParam, and not bindValue.

对于某些数据库引擎，存储过程可以具有可用于输入（从 PHP 向过程提供值）和输出（从存储过程向 PHP 返回值）的参数；要绑定这些参数，您必须使用 bindParam，而不是 bindValue。

回答by Nezar Fadle

From Prepared statements and stored procedures

从准备好的语句和存储过程

Use bindParamto insert multiple rows with one time binding:

用于bindParam一次性插入多行：

<?php

$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (?, ?)");
$stmt->bindParam(1, $name);
$stmt->bindParam(2, $value);

// insert one row
$name = 'one';
$value = 1;
$stmt->execute();

// insert another row with different values
$name = 'two';
$value = 2;
$stmt->execute();

回答by Denilson Sá Maia

For the most common purpose, you should use bindValue.

对于最常见的目的，您应该使用bindValue.

bindParamhas two tricky or unexpected behaviors:

bindParam有两个棘手或意外的行为：

• bindParam(':foo', 4, PDO::PARAM_INT)does not work, as it requires passing a variable (as reference).
• bindParam(':foo', $value, PDO::PARAM_INT)will change $valueto string after running execute(). This, of course, can lead to subtle bugs that might be difficult to catch.

• bindParam(':foo', 4, PDO::PARAM_INT)不起作用，因为它需要传递一个变量（作为参考）。
• bindParam(':foo', $value, PDO::PARAM_INT)$value运行后会变成字符串execute()。当然，这会导致可能难以捕捉的细微错误。

Source: http://php.net/manual/en/pdostatement.bindparam.php#94711

来源：http: //php.net/manual/en/pdostatement.bindparam.php#94711

回答by tfont

The simplest way to put this into perspective for memorization by behavior (in terms of PHP):

将其置于行为记忆的最简单方法（就 PHP 而言）：

• bindParam:reference
• bindValue:variable

• bindParam:参考
• bindValue:多变的

回答by Thielicious

You don't have to struggle any longer, when there exists a way lilke this:

当存在这样的方法时，您不必再挣扎了：

$stmt = $pdo->prepare("SELECT * FROM someTable WHERE col = :val");
$stmt->execute([":val" => $bind]);