如何使用循环绑定mysqli参数并将结果存储在数组中? [英] How to bind mysqli parameters using loop and store results in array?

问题描述

$genre = array(
    'Action',
    'Adventure',
    'Fantasy'
);
$selectGenre_sql = 'SELECT genreID FROM genres WHERE dbGenre = ?';

if ($stmt->prepare($selectGenre_sql)) {
    // bind the query parameters
    $stmt->bind_param('s', $genre);
    // bind the results to variables
    $stmt->bind_result($genres);
    // execute the query
    $stmt->execute();
    $array1 = array();
    while ($stmt->fetch()) {
        $array1[] = $genres;
    }
}

当dbGenre等于$genre时，上面的代码从genreID获取值.然后将结果存储在数组中.但这是行不通的，因为$genre是一个数组，所以我需要遍历它，以便每次都从genreID获得一个不同的值.

The code above gets the value from genreID when dbGenre is equal to $genre. And then store the results in an array. But it's not working because $genre is an array, so I need to loop through it to get a different value from genreID each time.

类型"表包含两列: genreID(INT)和 dbGenre(VARCHAR)

The 'genres' table contains two columns: genreID (INT) and dbGenre (VARCHAR)

我只需要每个genreID(即一个数字)...假设dbGenre等于Action，然后将genreID存储在array1中，然后循环$ genre数组以获取下一个值的genreID，然后再次将其存储在array1中.

I just need each genreID (that is a number)... Let's say when dbGenre is equal to Action, then store the genreID in an array1, and then loop the $genre array to get the genreID for the next value and store it again in array1.

我该如何解决?

推荐答案

您不能将数组绑定到SQL参数.您可以在SQL中使用参数代替单个文字值.不是值列表，表达式，列名或表名.

You can't bind an array to an SQL parameter. You can use a parameter in SQL in place of a single literal value. Not a list of values, or an expression, or a column name or table name.

要解决您的情况下的任务，可以使用以下两种解决方案之一:

To solve the task in your case, you can use either of two solutions:

第一个解决方案:遍历$genre数组，一次绑定每个值，并对每个值执行SQL查询.

First solution: loop over $genre array, bind each value one at a time and execute the SQL query for each value.

$stmt->prepare($selectGenre_sql);
$genre = array();
foreach ($gengre as $genreID) {
    $stmt->bind_param('s', $genreID);
    $stmt->execute();
    $stmt->bind_result($genres);
    while ($stmt->fetch()) {
        $genre[] = $genres;
    }
}

第二个解决方案:使用多个参数一次执行查询，每个参数对应数组中的每个值.这需要一些棘手的代码才能在SQL查询中构建可变数量的?占位符，并用逗号分隔.

Second solution: execute the query once, with multiple parameters, one for each value in the array. This requires some tricky code to build a variable number of ? placeholders in the SQL query, separated by commas.

$selectGenre_sql = 'SELECT genreID FROM genres WHERE dbGenre IN ('
 . join(',', array_fill(0, count($genre), '?')) . ')';

此外，您还需要根据$genre数组中的元素使用可变数量的参数来巧妙地调用bind_param():

Also you need to get tricky calling bind_param() with a variable number of arguments based on the elements in your $genre array:

$stmt->prepare($selectGenre_sql);
$temp = array();
foreach ($genre as $key => $value) {
    $temp[] = &$genre[$key];
}

array_unshift($genre, str_repeat('i', count($genre)));
call_user_func_array(array($stmt, 'bind_param'), $genre);

$stmt->execute();

$stmt->bind_result($genres);

$array1 = array();
while ($stmt->fetch()) {
    $array1[] = $genres;
}

您可能要考虑使用PDO_MYSQL，因为从数组绑定参数更容易.在这种情况下，MySQLi界面非常尴尬.

You might want to consider using PDO_MYSQL because it's easier to bind parameters from an array. The MySQLi interface is pretty awkward for this case.

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