Use mysql_fetch_array() to obtain information in the array result set (PHP method 4 for operating MySQL database)-Mysql Tutorial-php.cn

Use mysql_fetch_array() to obtain information in the array result set (PHP method 4 for operating MySQL database)

黄舟

Release： 2019-02-25 16:28:55

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How PHP operates the MySQL database - use the mysql_fetch_array() function to obtain information in the array result set

The mysql_fetch_array() function obtains a row from the result set as an association Array, or numeric array, or both Returns an array based on the rows taken from the result set, or false if there are no more rows.

In the previous article "Using the mysql_query() function to execute SQL statements (PHP method three for operating MySQL database)", the mysql_query() function is introduced to execute SQL statements. Next, use The mysql_fetch_array() function fetches information from the result set.

Related mysql video tutorial recommendations: "mysql tutorial"

mysql_fetch_array() The syntax structure of the function is as follows:

array mysql_fetch_array(resource result[,int result_type])

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result: resource Type parameter, what is passed in is the data pointer returned by the mysql_query() function.

result_type: optional, integer parameter, to be passed in are 3 index types: MYSQL_ASSOC (associative index), MYSQL_NUM (numeric index), MYSQL_BOTH (array containing both associative and numeric indexes), default value for MYSQL_BOTH.

Note:

The field names returned by the mysql_fetch_array() function are case-sensitive. This is the most easily overlooked issue for beginners.

The following example implements a retrieval function. First, use the mysql_query() function to execute SQL statements and query information, then use the mysql_fetch_array() function to obtain the query results, and finally use echo data to output the array result set.

The specific development steps are as follows:

1. Create a PHP dynamic page, name it index.php, add a form, a text box and a submit button to index.php. The specific code is as follows ：

<html>
<body>
    <!--上传文件表单-->
    <form method="post" action="" name = form1>
        <table>
           <tr>
               <td width="605" height="51" bgcolor="#CC99FF">
                   <p align="center">请输入查询内容
                       <input type="text" name="txt_book" id="txt_book" size="25"> 
                       <input type="submit" name="Submit" value="查询">
                   </p>
               </td>
           </tr>
            </table>
        </form>
</body>
</html>

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2. Connect to the MySQL database server, select the database php_cn, and set the encoding format of the database to GB2312. The specific code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$link = mysql_connect("localhost","root","root")or die("连接数据库失败".mysql_error());
mysql_select_db("php_cn",$link);
mysql_query("set names gb2312");   //设置编码，防止发生乱发
?>

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3. Use the if conditional statement to determine whether the user clicks the "Query" button. If so, use the POST method to accept the passed information, and use the mysql_query() function to execute the SQL statement. The query The statement is mainly used to implement fuzzy query of information, and the query result is assigned to the variable $sql. Then use the mysql_fetch_array() function to obtain information from the array result set. The specific code is as follows:

<?php
$sql = mysql_query("select from tb_book");       //执行查询语句
$info = mysql_fetch_array($sql);                 //获取查询结果，返回值为数组
if($_POST[&#39;Submit&#39;]=="查询"){                    // 判断按钮的值是否为查询
    $txt_book = $_POST[&#39;txt_book&#39;];              //获取文本框提交的值
    $sql = mysql_query("select * from tb_book where bookname like &#39;%".trim($txt_book)."%&#39;");  //执行模糊查询
    $info = mysql_fetch_array($sql);             // 获取查询结果
     
}
?>

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Note:

The above example When querying blurred vision, the wildcard character "%" is used. "%" means zero or any more characters!

4. Use the if conditional statement to judge the result set variable $info. If the value is false, then use the echo statement to output that the retrieved information does not exist. The specific code is as follows:

<?php
if($info = false){  //如果检索的信息不存在，则输出相对的提示信息
    echo "<p align=&#39;center&#39; style=&#39;color: #FF0000;font-size: 12px&#39;>对不起，你要查询的信息不存在</p>";
}
?>

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5. Use the do...while loop statement to output the information in the array result set $info[] in tabular form. The name of a field is the index. Use the echo statement to output the information in the array $info[]. The specific code is as follows :

<?php
do {      //do...while 循环
    ?>
    <table>
        <tr align="left" bgcolor="#FFFFFF">
            <td height="20" align="center"><?php echo $info["id"] ?></td>
            <td height="20" align="center"><?php echo $info["bookname"] ?></td>
            <td height="20" align="center"><?php echo $info["data"] ?></td>
            <td height="20" align="center"><?php echo $info["price"] ?></td>
            <td height="20" align="center"><?php echo $info["maker"] ?></td>
            <td height="20" align="center"><?php echo $info["publisher"] ?></td>
        </tr>
    </table>
    <?php
}while($info = mysql_fetch_array($sql));
?>

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The output results are as follows:

Use mysql_fetch_array() to obtain information in the array result set (PHP method 4 for operating MySQL database)

We will introduce the use of the mysql_fetch_array() function here. In the next section, we will introduce the array results. Get a row in the result set as an object. For details, please read "Use the mysql_fetch_object() function to get a row in the result set as an object (Method 5 of PHP operating MySQL database)"!

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