Question

有3种不同的过滤器：books，authors和stores（select列表），我可以一次性使用它们，也可以只使用一次或两次他们，所以我使用UNION汇集所有查询

require('database.php');

if(isset($_POST['books'])){
    $books_ids = $_POST["books"];
}
if(isset($_POST['authors'])){
    $authors_ids = $_POST["authors"];
}
if(isset($_POST['stores'])){
    $stores_ids = $_POST["stores"];
}

$query = "";

if( !empty( $books_ids ))
{
    $books_ids_in = implode(',', array_fill(0, count($books_ids), '?'));

    $query .= "SELECT
        b.id,
        b.`name`,
        b.`year`,
        GROUP_CONCAT(DISTINCT a.`name`) AS author_names,
        GROUP_CONCAT(DISTINCT s.`name`) AS store_names,
        'book' as param
    FROM
        books AS b
        LEFT JOIN books_authors AS b_a ON b.id = b_a.book_id
        LEFT JOIN authors AS a ON a.id = b_a.author_id
        LEFT JOIN books_stores AS b_s ON b.id = b_s.book_id
        LEFT JOIN stores AS s ON s.id = b_s.store_id
    WHERE
        b.id IN (". $books_ids_in .")
    GROUP BY b.id
    ORDER BY b.id";
}

if( !empty( $authors_ids ) )
{
    $authors_ids_in = implode(',', array_fill(0, count($authors_ids), '?'));

    if (!empty($query)) {
         $query .= " UNION ";
    }

    $query .= "SELECT
        b.id,
        b.`name`,
        b.`year`,
        GROUP_CONCAT(DISTINCT a.`name`) AS author_names,
        GROUP_CONCAT(DISTINCT s.`name`) AS store_names,
        'author' as param
    FROM
        books AS b
        LEFT JOIN books_authors AS b_a ON b.id = b_a.book_id
        LEFT JOIN authors AS a ON a.id = b_a.author_id
        LEFT JOIN books_stores AS b_s ON b.id = b_s.book_id
        LEFT JOIN stores AS s ON s.id = b_s.store_id
    WHERE
        b.id IN (
            SELECT DISTINCT book_id FROM books_authors WHERE author_id IN (". $authors_ids_in .")
            )
    GROUP BY b.id
    ORDER BY b.id";
}

if( !empty( $stores_ids ) )
{
    $stores_ids_in = implode(',', array_fill(0, count($stores_ids), '?'));

    if (!empty($query)) {
         $query .= " UNION ";
    }

    $query .= "SELECT
        b.id,
        b.`name`,
        b.`year`,
        GROUP_CONCAT(DISTINCT a.`name`) AS author_names,
        GROUP_CONCAT(DISTINCT s.`name`) AS store_names,
        'store' as param
    FROM
        books AS b
        LEFT JOIN books_authors AS b_a ON b.id = b_a.book_id
        LEFT JOIN authors AS a ON a.id = b_a.author_id
        LEFT JOIN books_stores AS b_s ON b.id = b_s.book_id
        LEFT JOIN stores AS s ON s.id = b_s.store_id
    WHERE
        b.id IN (
            SELECT DISTINCT book_id FROM books_stores WHERE store_id IN (". $stores_ids_in .")
            )
    GROUP BY b.id
    ORDER BY b.id";
}


if( !empty( $query )) {

    $stmt = $conn->prepare($query); 

    if( !empty( $books_ids ))
    {
        foreach ($books_ids as $k => $id) {
            $stmt->bindValue(($k+1), $id);
        }
    }

    if( !empty( $authors_ids ))
    {
        foreach ($authors_ids as $k => $id) {
            $stmt->bindValue(($k+1), $id);
        }
    }

    if( !empty( $stores_ids ))
    {
        foreach ($stores_ids as $k => $id) {
            $stmt->bindValue(($k+1), $id);
        }
    }

    $stmt->execute();
    $results = $stmt->fetchAll();
    echo json_encode($results);
}

$conn = null;

当我只使用一个过滤器时，

代码工作正常，但当我尝试使用2个或更多时，我得到错误

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens' in C:\xampp\htdocs\bookstore\filter.php:123 Stack trace: #0 C:\xampp\htdocs\bookstore\filter.php(123): PDOStatement->execute() #1 {main} thrown in C:\xampp\htdocs\bookstore\filter.php on line 123

我想，bindValue使用了一些问题，但我不知道如何解决这个问题？

UPD var_dump($query)（选择3本书和2位作者）
string(1097) "SELECT b.id, b.名称, b.年, GROUP_CONCAT(DISTINCT a.名称) AS author_names, GROUP_CONCAT(DISTINCT s.名称) AS store_names, 'book' as param FROM books AS b LEFT JOIN books_authors AS b_a ON b.id = b_a.book_id LEFT JOIN authors AS a ON a.id = b_a.author_id LEFT JOIN books_stores AS b_s ON b.id = b_s.book_id LEFT JOIN stores AS s ON s.id = b_s.store_id WHERE b.id IN (?,?,?) GROUP BY b.id ORDER BY b.id UNION SELECT b.id, b.名称, b.年, GROUP_CONCAT(DISTINCT a.名称) AS author_names, GROUP_CONCAT(DISTINCT s.名称{{ 1}}

Answer 1

您的代码存在构建动态查询的问题。在构建动态查询时，您需要将查询中那些静态的部分与动态查询部分分开。

您可以看到以下代码是静态的。

# create a mapping of state to abbreviation

states = {
    'Oregan': 'OR',
    'Florida': 'FL',
    'California': 'CA',
    'New York' : 'NY',
    'Michigan' : 'MI'
    }

print "-"*10
for state, abbrev in states.items():
    print "%s has the city %s" % (state, abbrev)

print "-"*10
for test in states.items():
    print "%s has the city %s" % (test)

还

$query = "SELECT
        b.id,   
        b.`name`,
        b.`year`,
        GROUP_CONCAT(DISTINCT a.`name`) AS author_names,
        GROUP_CONCAT(DISTINCT s.`name`) AS store_names,
        'book' as param
    FROM
        books AS b
        LEFT JOIN books_authors AS b_a ON b.id = b_a.book_id
        LEFT JOIN authors AS a ON a.id = b_a.author_id
        LEFT JOIN books_stores AS b_s ON b.id = b_s.book_id
        LEFT JOIN stores AS s ON s.id = b_s.store_id ";

其余代码是动态的。过滤记录时，使用WHERE子句和AND＆amp; OR运算符用于根据多个条件过滤记录。如果第一个条件和第二个条件都为真，则AND运算符显示记录。如果第一个条件或第二个条件为真，则OR运算符显示记录。因此，对于第一个条件，使用WHERE但在此之后必须使用AND或OR（在您的示例中使用OR）

" GROUP BY b.id
  ORDER BY b.id";

要允许应用不同的过滤器，您可以使用flag。

// Static code
sql = "SELECT * FROM `table`"
// Set initial condition to WHERE       
clause = "WHERE";       
if( !empty( filter )){
    Add clause to sql 
    Add condition to sql
    change clause to OR or AND as required
}
Repeat for each filter
Note the filter is not changed until a filter is  not empty and remains changed once changed.
The remaining static code is added after all the filters have been handled

尽可能使用“lazy”绑定 - 将数据传递给execute将大大缩短您的代码。见PDO info 您需要合并数组才能执行此操作。使用带有标志的switch语句可以合并所需的数组。

$flag = 0;
if(isset($_POST['books'])){
    $books_ids = $_POST["books"];
    $flag += 1;

}
if(isset($_POST['authors'])){
    $authors_ids = $_POST["authors"];
    $flag += 10;
}
if(isset($_POST['stores'])){
    $stores_ids = $_POST["stores"];
    $flag += 100;
}

以下代码使用以上几点。我已经回应了一些行来指示一旦测试完成就可以删除的结果。还有一些代码已被注释掉用于测试。

switch ($flag) {
    case 1:
        $param_array = $books_ids;
        break;
    case 10:
        $param_array = $authors_ids;
        break;
    case 100:
        $param_array = $stores_ids;
        break;
    case 11://books & authors
        $param_array = array_merge($books_ids, $authors_ids); 
        break;
    case 101://books & stores
        $param_array = array_merge($books_ids, $stores_ids); 
        break;
    case 110://authors & stores
        $param_array = array_merge($authors_ids, $stores_ids); 
        break;
     case 111://books & authors & stores
        $param_array = array_merge(array_merge($books_ids,$authors_ids),$stores_ids);
        break;  

}

if( !empty( $query )) {
    $stmt = $conn->prepare($query); 
    $stmt->execute($param_array);
    $results = $stmt->fetchAll();
    echo json_encode($results);
}

Answer 2

不要使用相同的$ k;使用变量并使用每个绑定递增它;见下文

$bindingIndex = 0;
if( !empty( $books_ids ))
{
    foreach ($books_ids as $k => $id) {
        $stmt->bindValue((++$bindingIndex), $id);
    }
}

if( !empty( $authors_ids ))
{
    foreach ($authors_ids as $k => $id) {
        $stmt->bindValue((++$bindingIndex), $id);
    }
}

if( !empty( $stores_ids ))
{
    foreach ($stores_ids as $k => $id) {
        $stmt->bindValue((++$bindingIndex), $id);
    }
}

在pdo中绑定多个数组

2 个答案: