Php connects to the database for simple query

: This article describes how to use php to connect to a database for simple queries. For more information about PHP tutorials, see. Hey, I just learned, record it ~

1. first create a database, create a data table test in it, and insert two records at will.

2. create a php file.

Database Connection code:

$ Conn = mysql_connect ("localhost", "root", ""); // connect to the database server if (! $ Conn) {die ('could not connect :'. mysql_error ();} mysql_select_db ("mytest", $ conn); // select the database mytetstmysql_query ("set names utf8"); // set the encoding format

Mysql_connect (servername, username, password );

Servername	Optional. Specifies the server to be connected. The default value is localhost: 3306 ".
Username	Optional. Specifies the username used for logon. The default value is the name of the user who owns the server process.
Password	Optional. Specifies the password used for logon. The default value is "".

3. execute database statements, such as query statements

$arr=mysql_query("select * from test",$conn);

Output query results

       while($row = mysql_fetch_array($arr)){echo $row['id'] . " " . $row['num'];echo "
";}

----------------------------------------

Implementation result:

When you click "search all", it is displayed as follows:

When searching by id, enter 1 to display:

Complete code:

  "; Echo"IdNumNameSexBithday"; If (isset ($ _ POST ['Select _ all']) {$ arr = mysql_query (" select * from test ", $ conn ); while ($ row = mysql_fetch_array ($ arr) {echo"{$ Row ['id']}{$ Row ['num']}{$ Row ['name']}{$ Row ['sex']}{$ Row ['birthday']}"; // Echo $ row ['id']." ". $ row ['num']; // echo"
";}} Else if (isset ($ _ POST ['Select _ sure ']) {$ id = $ _ POST ['Select _ INDEX']; $ arr = mysql_query ("select * from test where id = $ id", $ conn); if ($ row = mysql_fetch_assoc ($ arr )) {// if the queried echo"{$ Id}{$ Row ['num']}{$ Row ['name']}{$ Row ['sex']}{$ Row ['birthday']}";}} Echo""; Mysql_close ($ conn);?>

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