Question

我从其他语言到PHP并尝试创建一个函数，该函数返回一个包含sql，params和param类型的sql查询对象。

代码：

function buildSQLWhereClause($conn, $place) {
    $query = "SELECT p.*, s.* FROM product p INNER JOIN product_shop ps ON ps.p_id = p.p_id INNER JOIN shop s ON s.s_id = ps.s_id WHERE ";
    $queryParams = [];
    $queryParamTypes = "";
    $i = 0;
    $len = count($place);
    foreach ($place as $key => $value) {
        if ($i == $len - 1) {
            $query .= "$key = ?";
            $queryParams[] = $value;
            $queryParamTypes .= "s";
        } else {
            $query .= "$key = ? AND ";
            $queryParams[] = $value;
            $queryParamTypes .= "s";
        }
        $i++;
    }

    return array(
            "query" => $query,
            "queryParams" => $queryParams,
            "queryParamTypes" => $queryParamTypes
        );
}

$queryObject = buildSQLWhereClause($conn, $place);
$query = queryObject['query'];
$queryParams = queryObject['queryParams'];
$queryParamTypes = queryObject['queryParamTypes'];

$ queryObject保存正确的信息。但是如何访问$queryObject中的信息？ $query, $queryParams, and $queryParamTypes都保留值"q"。为什么这3个变量不能保持$queryObject的预期值？

php错误日志：

[05-May-2016 19:14:25 Pacific/Auckland] PHP Notice:  Use of undefined constant queryObject - assumed 'queryObject' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 47
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:14:25 Pacific/Auckland] PHP Warning:  Illegal string offset 'query' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 47
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:14:25 Pacific/Auckland] PHP Notice:  Use of undefined constant queryObject - assumed 'queryObject' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 48
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:14:25 Pacific/Auckland] PHP Warning:  Illegal string offset 'queryParams' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 48
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:14:25 Pacific/Auckland] PHP Notice:  Use of undefined constant queryObject - assumed 'queryObject' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 49
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:14:25 Pacific/Auckland] PHP Warning:  Illegal string offset 'queryParamTypes' in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 49
[05-May-2016 19:14:25 Pacific/Auckland] PHP Stack trace:
[05-May-2016 19:14:25 Pacific/Auckland] PHP   1. {main}() /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:0
[05-May-2016 19:14:25 Pacific/Auckland] PHP   2. queryDbForProducts($conn = *uninitialized*, $place = *uninitialized*) /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:105
[05-May-2016 19:17:51 Pacific/Auckland] PHP Fatal error:  Uncaught Error: Call to a member function bind_param() on boolean in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php:55
Stack trace:
#0 /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php(105): queryDbForProducts(Object(mysqli), Array)
#1 {main}
  thrown in /Applications/MAMP/htdocs/the_vegan_repository/scripts/back_end/get_products.php on line 55

Answer 1

您忘记将$放在queryObject前面。这应该有效：

$query = $queryObject['query'];
$queryParams = $queryObject['queryParams'];
$queryParamTypes = $queryObject['queryParamTypes'];

PHP访问对象中的数据

1 个答案: