Php ram_阵列）；//测试后移除 /* 如果（！empty（$query））{ $stmt=$conn->prepare（$query）； $stmt->execute（$param_数组）； $results=$stmt->fetchAll（）； echo json_编码（$results）； } $conn=null；_Php_Mysql_Pdo

Php ram_阵列）；//测试后移除 /* 如果（！empty（$query））{ $stmt=$conn->prepare（$query）； $stmt->execute（$param_数组）； $results=$stmt->fetchAll（）； echo json_编码（$results）； } $conn=null；

php mysql

Php ram_阵列）；//测试后移除 /* 如果（！empty（$query））{ $stmt=$conn->prepare（$query）； $stmt->execute（$param_数组）； $results=$stmt->fetchAll（）； echo json_编码（$results）； } $conn=null；,php,mysql,pdo,Php,Mysql,Pdo,不要使用相同的$k；使用一个变量并在每次绑定时递增它；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 =>

不要使用相同的$k；使用一个变量并在每次绑定时递增它；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);
    }
}

该错误意味着您的绑定值少于/多于查询中预期的值。我会回显每个bindValue循环的计数以找到罪魁祸首。不，参数的数量与查询中的数量相同，我已经检查过了。我选择了3本书和2位作者，在我的查询中，

WHERE b.id in（？，？）

和

WHERE author\u id in（？，）

var\u dump（$query）；并显示结果请直接运行查询，因为它应该与值一起运行吗？绑定“IN”可能无法正常工作。问题是，我可以使用全部3个筛选器，或者只能使用其中的1或2个，因此我可以将

$books\u id

、

$authors\u id

和

$stores\u id

数组全部或仅使用其中的1或2个。在本例中，我遇到了类似于

的错误注意：未定义的变量：C:\xampp\htdocs\bookstore\filter.php中的books\u id（第130行）警告：array\u merge（）：Argument#1不是C:\xampp\htdocs\bookstore\filter.php中的数组（第130行）

$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 ";

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

// 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

$flag = 0;
if(isset($_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;
}

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);
}

//Set flag
$flag = 0;
if(isset($_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;
}
echo $flag. " <BR>";//Remove after testing

//Basic SQL statement 
$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 ";
// Set initial condition to WHERE       
$clause = "WHERE";      

if( !empty( $books_ids ))
{
    $books_ids_in = implode(',', array_fill(0, count($books_ids), '?'));
    $query .= $clause;
    $query .= " b.id IN (". $books_ids_in .")";
    // Set condition to OR for additional condition
    $clause = " OR ";   
}
if( !empty( $authors_ids ) )
{
    $authors_ids_in = implode(',', array_fill(0, count($authors_ids), '?'));

    /*  This part commented out as I don't see relevance
        if (!empty($query)) {
         $query .= " UNION ";
    }
    */
    $query .= $clause;
    $query .= "    b.id IN (
            SELECT DISTINCT book_id FROM books_authors WHERE author_id IN (". $authors_ids_in .")
            )";
    // Set condition to OR for additional condition     
    $clause = " OR ";       

}


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

    /* if (!empty($query)) {
         $query .= " UNION ";
    }
    */
    $query .= $clause;
    $query .= " b.id IN (
            SELECT DISTINCT book_id FROM books_stores WHERE store_id IN (". $stores_ids_in .")
            )";
    $clause = " OR ";
}

//Add GROUP & ORDER
    $query .= " GROUP BY b.id
    ORDER BY b.id";
echo $query; //Remove after testing
//building $param_array
switch ($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;  

}
echo "<br>";
print_r($param_array);// remove after testing
/*
if( !empty( $query )) {
    $stmt = $conn->prepare($query); 
    $stmt->execute($param_array);
    $results = $stmt->fetchAll();
    echo json_encode($results);
}

$conn = null;

$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);
    }
}