Question

我从表中随机选择5行。

$query = "SELECT stdid, name FROM students order by rand(UNIX_TIMESTAMP()) limit 5"
$myquery = mysqli_query($db_connect, $query);
while($students = mysqli_fetch_assoc($myquery)){
    $stdid =$students['stdid']; $name = $students['name']; $dept = $students['dept'];
    echo "<br><br>".$stdid."<br>".$name."<br>".$dept;
//NOT SURE IF I ADD INSERT HERE     
}

我想将显示的'stdid'插入（5行）到另一个表中。

我是否需要在WHILE循环中添加INSERT？还有另一种方法可以解决这个问题吗？

非常感谢。

Answer 1

将插入放在while循环中是有效的。只有五个条目，这不会太低效。如果要一次插入所有值，则应该查看有关如何执行此操作的问题。 Inserting multiple rows in a single SQL query?

Answer 2

使用PHP MySQLi预处理语句准备插入查询，在循环外部，然后重用该准备插入对象以将值转储到循环内的所需表中：

$query1 = "SELECT stdid, name FROM students order by rand(UNIX_TIMESTAMP()) limit 5";
$myquery1 = mysqli_query($db_connect, $query1);

// prepare insert stdid
$query2 = "INSERT INTO someothertable (stdid) VALUES (?)";
$myquery2 = mysqli_prepare($db_connect, $query2);
mysqli_stmt_bind_param($myquery2, 'i', $stdid);

while($students = mysqli_fetch_assoc($myquery1)){
    $stdid =$students['stdid']; $name = $students['name']; $dept = $students['dept'];
    echo "<br><br>".$stdid."<br>".$name."<br>".$dept;

    // insert stdid
    mysqli_execute($myquery2);
}

Answer 3

您只需插入上述语句即可。下面是一些代码，可以帮助您制作一个准备好的语句，该语句将添加未预定义的值。

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$mysqli->query("CREATE TABLE myCity LIKE City");

/* Prepare an insert statement */
$query = "INSERT INTO myCity (Name, CountryCode, District) VALUES (?,?,?)";
$stmt = $mysqli->prepare($query);

$stmt->bind_param("sss", $val1, $val2, $val3);

$val1 = 'Stuttgart';
$val2 = 'DEU';
$val3 = 'Baden-Wuerttemberg';

/* Execute the statement */
$stmt->execute();

$val1 = 'Bordeaux';
$val2 = 'FRA';
$val3 = 'Aquitaine';

/* Execute the statement */
$stmt->execute();

/* close statement */
$stmt->close();

取自手册。希望它有所帮助！

如何在另一个表中插入返回的值

3 个答案: