如何在一個PHP if語句中運行2個SQL查詢？

Question

這是我到目前為止的代碼

if (isset($_POST['button1']))
    {
        $sql = "DELETE FROM UpcomingRota";
        $E1 = $_POST["MondayAMFirstEmployee"]; $E2 = $_POST["MondayAMSecondEmployee"]; $E3 = $_POST["MondayAMThirdEmployee"];
        $sql = "INSERT INTO UpcomingRota (DayAndTime, FirstEmployee, SecondEmployee, ThirdEmployee) VALUES ('MondayAM', '$E1', '$E2', '$E3')";

    }

這兩個$ sql語句都可以完美地自己工作，但是當我在if語句中都使用它時，它似乎繞過了第一個而只運行了最后一個$ sql語句。

我怎樣才能讓它運行盡可能多的$ sql語句……要在那里大約15-20。

提前致謝。

根據要求提供更多代碼。

$servername = "db568845851.db.1and1.com";
    $username = "dbo568845851";
    $password = "";
    $dbname = "db568845851";

    // Create connection
    $conn = new mysqli($servername, $username, $password, $dbname);

    if (isset($_POST['button1']))
    {
        $sql = "DELETE FROM UpcomingRota";
        $E1 = $_POST["MondayAMFirstEmployee"]; $E2 = $_POST["MondayAMSecondEmployee"]; $E3 = $_POST["MondayAMThirdEmployee"];
        $sql = "INSERT INTO UpcomingRota (DayAndTime, FirstEmployee, SecondEmployee, ThirdEmployee) VALUES ('MondayAM', '$E1', '$E2', '$E3')";

    }

    if ($conn->query($sql) === TRUE) {
        echo "New record created successfully";
    } else {
        echo "Error: " . $sql . "<br>" . $conn->error;
    }

Answer 1

第二個語句將覆蓋第一個語句。 您可以使用以下語法將第二個查詢追加到第一個查詢：

$sql = "First statement;"; // Statements are separated by a ;
$sql .= "Second statement;";

// (Notice the . before the = on the second line)
// $sql now contains "First statement;Second Statement;"

您還需要確保您正在以支持多查詢的方式使用數據庫適配器執行查詢：

http://php.net/manual/en/mysqli.multi-query.php

Answer 2

$sql = "DELETE FROM UpcomingRota";
$myResult = mysql_query($sql);
        $E1 = $_POST["MondayAMFirstEmployee"]; $E2 = $_POST["MondayAMSecondEmployee"]; $E3 = $_POST["MondayAMThirdEmployee"];
        $sql = "INSERT INTO UpcomingRota (DayAndTime, FirstEmployee, 
SecondEmployee, ThirdEmployee) VALUES ('MondayAM', '$E1', '$E2', '$E3')";
$myResult = mysql_query($sql);

您必須執行查詢。

Answer 3

原來是因為我只是在表中做很多插入操作，所以我應該這樣做。

INSERT INTO TABLE (column1, column2) VALUES ('data', 'data'), ('data', 'data')

至今為止。