php mysqli query 查询数据库后读取内容的方法

最新推荐文章于 2022-01-09 21:03:44 发布

转载最新推荐文章于 2022-01-09 21:03:44 发布 · 541 阅读

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#数据库 #php

本文介绍使用PHP的mysqli查询数据库并读取内容的方法，包括创建临时表、执行选择查询和使用MYSQLI_USE_RESULT优化大体量数据获取。

php mysqli query 查询数据库后读取内容的方法

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

/* check connection */
if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

/* Create table doesn't return a resultset */
if ($mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    printf("Table myCity successfully created.\n");
}

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    printf("Select returned %d rows.\n", $result->num_rows);

    /* free result set */
    $result->close();
}

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
if ($result = $mysqli->query("SELECT * FROM City", MYSQLI_USE_RESULT)) {

    /* Note, that we can't execute any functions which interact with the
       server until result set was closed. All calls will return an
       'out of sync' error */
    if (!$mysqli->query("SET @a:='this will not work'")) {
        printf("Error: %s\n", $mysqli->error);
    }
    $result->close();
}

$mysqli->close();
?>

实例代码：

$sql="select * from qa limit 0,10";
$result=$mysqli->query($sql);
while ($row = mysqli_fetch_assoc($result))
{
    echo "question_title : {$row['question_title']} <br>";
    echo "answer_content1: {$row['answer_content1']} <br>";
}
/* free result set */
    $result->close();

参考文档：http://www.php.net/manual/en/mysqli.query.php