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This is a simple introductory article on querying data with PHP and MySQL. We have talked about the most important functions and introduced them in detail. Students in need can take a look.

The code is as follows

代码如下	复制代码
//链接数据库 $conn = @mysql_connect("localhost","root","88888888") or die ("链接错误"); /* mysql_connect() 函数打开非持久的 MySQL 连接。

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//Link database

$conn = @mysql_connect("localhost","root","88888888") or die ("Link Error");

/*
The mysql_connect() function opens a non-persistent MySQL connection.

Grammar

代码如下	复制代码
//解决中文乱码 mysql_query("set names 'GBK'");  //打开数据库 mysql_select_db("wordpress",$conn) or die("打开失败"); $sql = "select * from wp_posts";

mysql_connect(server,user,pwd,newlink,clientflag) parameter description

server is optional. Specifies the server to connect to.

Can include a port number, such as "hostname:port", or a path to a local socket, such as ":/path/to/socket" for localhost.

If the PHP directive mysql.default_host is not defined (the default case), the default value is 'localhost:3306'.

user optional. username. The default value is the username of the server process owner.
pwd Optional. password. The default value is an empty password.

*/

The mysql_select_db() function sets the active MySQL database.

The code is as follows

代码如下	复制代码
//执行sql语句 $result = mysql_query($sql,$conn); //循环打印所需参数 while($row = mysql_fetch_array($result)) {     echo $row[4]." ";//测验多次，$row[4]中只能为索引，不能为列名，郁闷中ing }

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//Solve Chinese garbled characters

mysql_query("set names 'GBK'");

//Open database
mysql_select_db("wordpress",$conn) or die("Open failed");

$sql = "select * from wp_posts";

If successful, the function returns true. If failed, returns false.

Grammar

mysql_select_db(database,connection) parameter description database required. Specifies the database to be selected. connection is optional. Specifies the MySQL connection. If not specified, the previous connection is used.

The code is as follows

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//Execute sql statement $result = mysql_query($sql,$conn); //Loop to print the required parameters while($row = mysql_fetch_array($result)) { echo $row[4]." ";//Tested many times, $row[4] can only be an index, not a column name, I am depressed } The mysql_fetch_array() function fetches a row from the result set as an associative array, a numeric array, or both Returns an array based on the rows taken from the result set, or false if there are no more rows. Grammar mysql_fetch_array(data,array_type) parameter description data optional. The specification specifies the data pointer to be used. This data pointer is the result of the mysql_query() function. array_type optional. Specifies what kind of results are returned. Possible values: MYSQL_ASSOC - Associative array MYSQL_NUM - array of numbers MYSQL_BOTH - Default. Produce both associative and numeric arrays http://www.bkjia.com/PHPjc/629152.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/629152.htmlTechArticleThis is a simple introductory article on querying data with php and mysql. We have talked about the most important points. Each function is introduced in detail, students who need it can take a look. The code is as follows...