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PHP新手上路（十一）

瀏覽：5日期：2024-03-01 10:35:20

數(shù)據(jù)庫(kù)鏈接 10. PHP最大的特色就是操作數(shù)據(jù)庫(kù)的能力特別的強(qiáng)大，PHP提供對(duì)多種數(shù)據(jù)庫(kù)的支持。通過PHP你可以輕松的連接到數(shù)據(jù)庫(kù)，請(qǐng)求數(shù)據(jù)并將其顯示在你的web站點(diǎn)中，甚至修改數(shù)據(jù)庫(kù)中的數(shù)據(jù)。在這一節(jié)里我們主要以在互聯(lián)網(wǎng)上跟PHP一起使用得最多的MySQL數(shù)據(jù)庫(kù)為例，介紹一下相關(guān)的MySQL數(shù)據(jù)庫(kù)的操作函數(shù)以及數(shù)據(jù)庫(kù)的基本操作等方面的知識(shí)。在MySQL數(shù)據(jù)庫(kù)中，我們用來連接數(shù)據(jù)庫(kù)的函數(shù)有兩個(gè)，它們分別為： integer mysql_connect(string host,string user,string password); integer mysql_pconnect(string host,string user,string password); mysql_connect函數(shù)和mysql_pconnect函數(shù)都是對(duì)指定主機(jī)上MySQL數(shù)據(jù)庫(kù)的連接，如果該數(shù)據(jù)庫(kù)位于一個(gè)不同的端口，則可以在主機(jī)名后加上冒號(hào)和端口號(hào)。函數(shù)的參數(shù)也可以缺省不填，如果不填參數(shù)，默認(rèn)的主機(jī)名是“l(fā)ocalhost”，用戶名為數(shù)據(jù)庫(kù)管理員，默認(rèn)值為“root”，密碼為空。與數(shù)據(jù)庫(kù)連接成功之后，這兩個(gè)函數(shù)都可以返回一個(gè)連接號(hào)，如果連接失敗，則返回一個(gè)false值。讓我們來看看下面幾句語句： <? $db=mysql_connect("localhost","user","password"); mysql_select_db("mydb",$db); ?> 注釋： $db=mysql_connect("localhost","user","password"); 我們將mysql的鏈接參數(shù)，包括主機(jī)名、用戶名和密碼作為mysql_connect()的參數(shù)，同時(shí)得到返回值為$db，這樣，在下面的語句中，我們就可以將變量$db作為一個(gè)連接mysql數(shù)據(jù)庫(kù)的連接號(hào)來使用。 mysql_select_db("mydb",$db); 將PHP程序鏈接到mydb數(shù)據(jù)庫(kù)中，這樣程序與數(shù)據(jù)庫(kù)的鏈接就完成了。 10.1 一個(gè)簡(jiǎn)易的數(shù)據(jù)庫(kù)留言簿在完成數(shù)據(jù)庫(kù)的鏈接之后，我們就可以對(duì)數(shù)據(jù)庫(kù)進(jìn)行一系列的操作。下面是一個(gè)簡(jiǎn)易的數(shù)據(jù)庫(kù)留言簿程序（guestbook.php3）：我假設(shè)你機(jī)子上的MySQL數(shù)據(jù)庫(kù)以及管理MYSQL數(shù)據(jù)庫(kù)的工具 Phpmyadmin_2. 0.5都已經(jīng)安裝完成，并且可以正常工作。我們要做的第一件事情是創(chuàng)建一個(gè)留言數(shù)據(jù)庫(kù)，假定名字為： mydb。 1、啟動(dòng)瀏覽器，打開Phpmyadmin_2. 0.5 的管理WEB界面。 2、在“Create new database”文本框內(nèi)輸入數(shù)據(jù)庫(kù)名稱mydb，然后按create按鍵。下一步，我們要在該留言數(shù)據(jù)庫(kù)下創(chuàng)建一個(gè)數(shù)據(jù)表，假定名字為： guestbook。創(chuàng)建該數(shù)據(jù)表的命令如下所示：;;CREATE TABLE guestbook (ID INT NOT NULL AUTO_INCREMENT, name CHAR(250), email CHAR(250), job CHAR(250), comments BLOB, PRIMARY KEY(ID));;;最后，將下面的留言簿程序挎貝到你機(jī)子的可寫目錄下面，并保存成guestbook.php3文件。就這么簡(jiǎn)單，你已經(jīng)有了自己的留言簿了。;;10.2 留言簿程序（guestbook.php3）： <?php;;/* $host : your MySQL-host, usually 'localhost' */ /* $user : your MYSQL-username */ /* $password : your MySQL-password */ /* $database : your MySQL-database */ /* $table : your MySQL-table */ /* $page_title : the title of your guestbook-pages */ /* $admin_mail : email-address of the administrator to send the new entries to */ /* $admin_name : the name of the administrator */ /* $html_mail : say yes if your mail-agent can handle HTML-mail, else say no */ $host = "localhost"$user = ""$password = ""$database = "mydb"$table = "guestbook"$page_title = "pert guestbook"$admin_mail = "pert@21cn.com"$admin_name = "Webmaster"$html_mail = "no"?> <HTML> <HEAD> <TITLE><?php echo $page_title; ?></TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#000000"> <FONT FACE="Verdana" SIZE="-2"> <? /* connect to the database */ mysql_pconnect("$host","$user","$password") or die("Can't connect to the SQL-server"); mysql_select_db("$database"); /* action=view : retrieve data from the database and show it to the user */ if($action == "view") { /* function for showing the data */ function search_it($name) { /* some vars */ global $offset,$total,$lpp,$dir; global $table,$html_mail,$admin_name,$admin_mail; /* select the data to get out of the database */ $query = "SELECT name, email, job, comments FROM $table"$result = mysql_query($query); $total= mysql_numrows($result); print "<CENTER><FONT FACE="Verdana" SIZE="-2"><A HREF="guestbook.php3?action=add" onMouseOver="window.status='Add your name';return true" onMouseOut="window.status='';return true" TITLE="Add your name">加入留言</A></FONT></CENTER><br><br>"if ($total== 0) { print "<CENTER>此刻沒人留言</CENTER><br><br>"} elseif ($total> 0) { /* default */ $counter=0; if ($dir=="") $dir="Next"$lpp=5; if ($offset==0) $offset=0; if ($dir=="Next") { if ($total > $lpp) { $counter=$offset; $offset+=$lpp; $num=$offset; if ($num > $total) { $num=$total; } } else { $num=$total; } } elseif ($dir=="Previous") { if ($total > $lpp) { $offset-=$lpp; if ($offset < 0) { $offset=0; } $counter=$offset-$lpp; if ($counter < 0) $counter=0; $num=$counter+$lpp; } else { $num=$total; } } while ($counter < $num) { $j=0; $j=$counter + 1; /* now really grab the data */ $i1=mysql_result($result,$counter,"name"); $i2=mysql_result($result,$counter,"email"); $i3=mysql_result($result,$counter,"job"); $i4=mysql_result($result,$counter,"comments"); $i4 = stripslashes ("$i4"); /* print it in a nice layout */ print "<CENTER>n"print "<TABLE WIDTH=400 BORDER=0 ALIGN=CENTER VALIGN=TOP><TR><TD><FONT FACE="Verdana" SIZE="-2">n"print "<HR>n"print "<BR><B>Name:</B> $i1n"print "<BR><B>email:</B><A HREF="mailto:$i2" onMouseOver="window.status='Email $i2';return true" onMouseOut="window.status='';return true" TITLE="Email $i2">$i2</A>n"print "<BR><B>Job:</B> $i3n"print "<BR><B>Comment:</B>n"print "<BR>$i4n"print "</FONT></TD></TR></TABLE>n"print "</CENTER>n"$counter++; } } mysql_close(); } /* execute the function */ search_it($name); /* See if we need to put on the NEXT or PREVIOUS buttons */ if ($total > $lpp) { echo("<form action="$PHP_SCRIPT" method="POST">n"); /* See if we need a PREVIOUS button */ if ($offset > $lpp) { echo("<input type="submit" value="Previous" name=dir>n"); } /* See if we need a NEXT button */ if ($offset < $total) { echo("<input type="submit" value="Next" name=dir>n"); } echo("<input type=hidden name="offset" value="$offset">n"); echo("<input type=hidden name="name" value="$name">n"); echo("</form>"); } } /* action=add : show a form where the user can enter data to add to the database */ elseif($action == "add") { ?> <TABLE WIDTH="460" ALIGN="CENTER" VALIGN="TOP"> <TH COLSPAN="2"><P>請(qǐng)您填寫留言</TH> <FORM NAME="guestbook" ACTION="guestbook.php3?action=send" METHOD="POST"> <TR> <TD ALIGN="RIGHT" VALIGN="TOP"> 您的大名:</TD> <TD><INPUT TYPE=text NAME=name></TD> </TR> <TR> <TD ALIGN="RIGHT" VALIGN="TOP"> 您的E-mail:</TD> <TD> <INPUT TYPE=text NAME=email></TD> </TR> <TR> <TD ALIGN="RIGHT" VALIGN="TOP"> 您的工作:</TD> <TD> <INPUT TYPE=text NAME=job></TD> </TR> <TR> <TD ALIGN="RIGHT" VALIGN="TOP"> 您的留言:</TD> <TD> <TEXTAREA NAME=comments COLS=40 ROWS=6></TEXTAREA> <P> <INPUT TYPE=submit VALUE=Submit> <INPUT TYPE=Reset VALUE=Reset>;;<A ALIGN="RIGHT" HREF="guestbook.php3?action=view" onMouseOver="window.status='Read all comments first';return true" onMouseOut="window.status='';return true" TITLE="Read all comments first"><FONT SIZE="-2">先觀看所有的留言</FONT></A> </TD> </TR> </FORM> </TABLE> </CENTER> <? } /* action=send : add the data from the user into the database */ elseif($action == "send") { /* check if a HTML-mail should be send or a plain/text mail */ if($html_mail == "yes") { mail("$admin_name <$admin_mail>","PHP3 Guestbook Addition","<HTML><BODY><FONT FACE="Century Gothic"><TABLE BORDER="0" WIDTH="100%" CELLSPACING="4"><TR>$name ($email) schreef het volgende bericht in het gastenboek :</TR><TR><TD ALIGN="LEFT"> </TD><TD ALIGN="LEFT" NOWRAP> </TD></TR><TR><TD ALIGN="LEFT">$comments</TD><TD ALIGN="LEFT" NOWRAP> </TD></TR><TR><TD ALIGN="LEFT"> </TD><TD ALIGN="LEFT" NOWRAP> </TD></TR><TR><TD ALIGN="LEFT">您的留言:</TD><TD ALIGN="LEFT" NOWRAP>$name</TD></TR><TR><TD ALIGN="LEFT">您的大名:</TD><TD ALIGN="LEFT" NOWRAP>$email</TD></TR><TR><TD ALIGN="LEFT">您的email:</TD><TD ALIGN="LEFT" NOWRAP>$job</TD></TR><TR><TD ALIGN="LEFT">您的工作:</TD></TR></TABLE></BODY></FONT></HTML>", "From: $name <$email>nReply-To: $name <$email>nContent-type: text/htmlnX-Mailer: PHP/" . phpversion()); } /* MySQL really hates it when you try to put things with ' or " characters into a database, so strip these...*/ $comments = addslashes ("$comments"); $query = "INSERT INTO guestbook VALUES('','$name', '$email', '$job', '$comments')"$result = MYSQL_QUERY($query); ?> <BR><P ALIGN = CENTER>感謝, <?php echo $name; ?>, 您的留言. <BR><P ALIGN = CENTER><A HREF="guestbook.php3?action=view" onMouseOver="window.status='View your comment now';return true" onMouseOut="window.status='';return true" TITLE="View your comment now">觀看留言</A><BR><BR> <? } /* if there's no action given, then we must show the main page */ else { /* get the number of entries written into the guestbook*/ $query = "SELECT name from guestbook"$result = MYSQL_QUERY($query); $number = MYSQL_NUMROWS($result); if ($number == "") { $entry = "還沒有人留過言"} elseif ($number == "1") { $entry = "目前留言人數(shù)1人"} else { $entry = "目前留言人數(shù) $number 人"} echo "<CENTER><BR>"echo "<P>$entry<BR>"echo "<H4><FONT FACE="Verdana" SIZE="3"><A HREF="guestbook.php3?action=add" onMouseOver="window.status='請(qǐng)您留言';return true" onMouseOut="window.status='';return true" TITLE="Add your name to our guestbook">請(qǐng)您留言</A></FONT></H4>"if ($number > "") { echo "<H4><FONT FACE="Verdana" SIZE="3"><A HREF="guestbook.php3?action=view" onMouseOver="window.status='觀看留言';return true" onMouseOut="window.status='';return true" TITLE="View the names in our guestbook">觀看留言</A></FONT></H4>"} echo "</P></CENTER>"} ?> <BR><SMALL><CENTER>版權(quán)所有：<A onMouseOver="window.status='pert';return true" onMouseOut="window.status='';return true" TITLE="pert">無邊天際</A></CENTER></SMALL> </FONT> </BODY> </HTML>;;

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