需要有关处理 PHP 文件中的操作 "read" 以处理 CRUD 操作的建议

Question

我正在尝试设置一个 PHP 文件来处理特定类型数据的 crud 操作 - "land contracts"。当前有 4 种情况我想从我的数据库中 read：

当设置acion="read"和land_contract_id时，则回显土地合同
当acion="create"时，然后在创建土地合同后回显它
当acion="update"时，更新土地合同后回显
当acion="read"和land_contract_id未设置时，则echo all land contract

我当前的设置适用于情况 1、2 和 3。但是，我无法在没有参数的情况下调用我的读取函数。即在情况 4 中，当 $land_contract_id 为 not 时。

当我想从我的数据库中读取时，我应该如何调整我的设置以在所有情况下工作？

下面是我设置的简化版本。

<?php

    $action = isset($_POST["action"]) ? $_POST["action"] : '';

    $land_contract_id = isset($_POST["land_contract_id"]) ? $_POST["land_contract_id"] : '';

    switch ($action) {
      case "create":

        // Here I'm creating a new land contract and getting the last inserted id with $pdo->lastInsertId()

        read($last_inserted_land_contract_id);

        break;
      case "read":

        if (isset($_POST['land_contract_id'])) {
          read($land_contract_id);
        }

        break;
      case "update":

        // Here I'm updating an existing land contract

        read($land_contract_id);

        break;
      case "delete":

        break;
    }

    function read(land_contract_id) {

      // Fetching land contract from database and echoing as JSON

    }

?>

--更新--

完整代码如下。根据@Jeff 的回答更新。函数 read 中的行 $stmt = $pdo->prepare($sql); 给了我 Fatal error: Uncaught Error: Call to a member function prepare() on null.

<?php

header("Content-Type: application/json; charset=UTF-8");

header("Access-Control-Allow-Origin: *");

require_once("./pdo_connect.php");

$action = isset($_POST["action"]) ? $_POST["action"] : '';
$land_contract_id = isset($_POST["land_contract_id"]) ? $_POST["land_contract_id"] : '';
$land_contract_name = isset($_POST["land_contract_name"]) ? $_POST["land_contract_name"] : '';
$location_id = isset($_POST["location_id"]) ? $_POST["location_id"] : '';
$land_contract_link = isset($_POST["land_contract_link"]) ? $_POST["land_contract_link"] : '';
$land_contract_notes = isset($_POST["land_contract_notes"]) ? $_POST["land_contract_notes"] : '';
$land_owner_id = isset($_POST["land_owner_id"]) ? $_POST["land_owner_id"] : '';
$land_contract_start_date = isset($_POST["land_contract_start_date"]) ? $_POST["land_contract_start_date"] : '';
$land_contract_end_date = isset($_POST["land_contract_end_date"]) ? $_POST["land_contract_end_date"] : '';
$land_contract_terminated = isset($_POST["land_contract_terminated"]) ? $_POST["land_contract_terminated"] : 'false';
$land_contract_payment_interval = isset($_POST["land_contract_payment_interval"]) ? $_POST["land_contract_payment_interval"] : '';
$land_contract_price_type = isset($_POST["land_contract_price_type"]) ? $_POST["land_contract_price_type"] : '';
$land_contract_fixed_annual_price = isset($_POST["land_contract_fixed_annual_price"]) ? $_POST["land_contract_fixed_annual_price"] : '';
$land_contract_variable_annual_price_year = isset($_POST["land_contract_variable_annual_price_year"]) ? $_POST["land_contract_variable_annual_price_year"] : '';

switch ($action) {
    case "create":

        // Insert land_contract to database
        $stmt1 = $pdo->prepare("INSERT INTO land_contract (land_contract_name, location_id, land_contract_link, land_contract_notes, land_owner_id, land_contract_start_date, land_contract_end_date, land_contract_terminated, land_contract_payment_interval, land_contract_price_type) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
        $stmt1->execute([$land_contract_name, $location_id, $land_contract_link, $land_contract_notes, $land_owner_id, $land_contract_start_date, $land_contract_end_date, $land_contract_terminated, $land_contract_payment_interval, $land_contract_price_type]);

        // Get id of last inserted land_contract
        $last_inserted_land_contract_id = $pdo->lastInsertId();


        // Check if there are any variable annual prices and if so, insert them into land_contract_annual_price
        if ( isset( $_POST['land_contract_variable_annual_price_year'] ) ) {
            $years = $_POST ['land_contract_variable_annual_price_year'] ;
            if( is_array( $years ) ) {
                foreach ( $years as $year => $price ) {

                    $price_with_decimals = number_format((float)$price, 2, '.', '');

                    // Insert the variable annual prices into land_contract_annual_price
                    $stmt2 = $pdo->prepare("INSERT INTO land_contract_annual_price (land_contract_annual_price_year, land_contract_annual_price_amount, land_contract_id) VALUES (?, ?, ?)");
                    $stmt2->execute([$year, $price_with_decimals, $last_inserted_land_contract_id]);

                }
            }
        }

        read($last_inserted_land_contract_id);

        // Reset statements
        $stmt1 = null;
        $stmt2 = null;

        break;
    case "read":

        if ( isset($_POST['land_contract_id']) ) {
            read($land_contract_id);
        }
        else {
            read();
        }

        break;
    case "update":

        $row = [
            'land_contract_id' => $land_contract_id,
            'land_contract_name' => $land_contract_name,
            'location_id' => $location_id,
            'land_contract_link' => $land_contract_link,
            'land_contract_notes' => $land_contract_notes,
            'land_owner_id' => $land_owner_id,
            'land_contract_start_date' => $land_contract_start_date,
            'land_contract_end_date' => $land_contract_end_date,
            'land_contract_terminated' => $land_contract_terminated,
            'land_contract_payment_interval' => $land_contract_payment_interval,
            'land_contract_price_type' => $land_contract_price_type,
            'land_contract_fixed_annual_price' => $land_contract_fixed_annual_price,
            'land_contract_variable_annual_price_year' => $land_contract_variable_annual_price_year

        ];

        $stmt = $pdo->prepare("UPDATE land_contract SET land_contract_name=:land_contract_name, location_id=:location_id, land_contract_link=:land_contract_link, land_contract_notes=:land_contract_notes, land_owner_id=:land_owner_id, land_contract_start_date=:land_contract_start_date, land_contract_end_date=:land_contract_end_date, land_contract_terminated=:land_contract_terminated, land_contract_payment_interval=:land_contract_payment_interval, land_contract_price_type=:land_contract_price_type, land_contract_fixed_annual_price=:land_contract_fixed_annual_price, land_contract_variable_annual_price_year=:land_contract_variable_annual_price_year WHERE land_contract_id=:land_contract_id");
        $stmt->execute($row);

        read($land_contract_id);

        $stmt = null;
        break;
    case "delete":
        $stmt = $pdo->prepare("DELETE FROM land_contract WHERE land_contract_id = ?");
        $stmt->execute([$land_contract_id]);
        $stmt = null;
        break;
}

function read($land_contract_id = null) {

    $params = [];
    $array = [];

    $sql = "SELECT lc.*, 
                   py.land_contract_annual_price_year AS `year`,  
                   py.land_contract_annual_price_amount AS `amount`
            FROM land_contract AS lc
            LEFT JOIN land_contract_annual_price AS py 
                ON py.land_contract_id = lc.land_contract_id
            ";
    if ($land_contract_id) {
        $sql .= 'WHERE lc.land_contract_id = ?';
        $params[] = $land_contract_id;
    }

    $stmt = $pdo->prepare($sql);
    $stmt->execute($params);
    while ($row = $stmt->fetch()) {
        // Fields we want to extract from the select statement into the array 
        $select_fields = ['land_contract_id', 'land_contract_name', 'location_id', 'land_contract_link', 'land_contract_notes', 'land_owner_id', 
                            'land_contract_start_date', 'land_contract_end_date', 'land_contract_terminated', 'land_contract_payment_interval', 
                            'land_contract_price_type', 'land_contract_fixed_annual_price '];

        if (!isset($array[$row['land_contract_id']])) {
            // initialize the subarray if it has not been set already 
            $array[$row['land_contract_id']] = array_intersect_key($row, array_flip($select_fields));

            if ($row['year'] != null) {
                $array[$row['land_contract_id']]['land_contract_annual_prices'] = [];
            } else {
                $array[$row['land_contract_id']]['land_contract_annual_price'] = $row['land_contract_fixed_annual_price'];
            }
        }

        if ($row['year'] != null) {
            $array[$row['land_contract_id']]['land_contract_annual_prices'][] = ['year' => $row['year'], 'amount' => $row['amount']];
        }

    }

    if (empty($array)) {
        echo "No results";
        exit;
    }

    echo json_encode($array, JSON_UNESCAPED_UNICODE);

    $stmt = null;
}

?>

Answer 1

您需要修改 read() 函数以使 $land_contract_id 可选：

function read($land_contract_id = null) {
    $sql = "SELECT * FROM land_contracts";

    if($land_contract_id) {
        $sql .= " WHERE land_contract_id = {$land_contract_id}";
    }

    $result = $database->select_rows($sql);
}

现在，$land_contract_id 是可选的。如果您将值传递给 read()，它将仅 return 选定的合同，否则如果您将其保留 null/empty，则它将 return 所有合同。

需要有关处理 PHP 文件中的操作 "read" 以处理 CRUD 操作的建议

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