Common PHP code (essential for beginners)

1. Connect to the MySQL database Code
<? PHP
$ Connec = mysql_connect ("localhost", "root", "root") or die ("cannot connect to the database server:". mysql_error ());
Mysql_select_db ("liuyanben", $ connec) or die ("the database cannot be selected:". mysql_error ());
Mysql_query ("set names 'gbk '");
?>

2. Read the database and implement cyclic output
<? PHP
$ SQL = "select * From liuyan order by ly_id DESC ";
$ Conn = mysql_query ($ SQL, $ connec );
While ($ rs = mysql_fetch_array ($ conn )){
?>
Loop content .........
<? PHP
}
?>

3. How to Implement paging, including two functions and two calls
1) two functions
// paging function
function genpage (& $ SQL, $ page_size = 2)
{< br> global $ prepage, $ nextpage, $ pages, $ sums; // out Param
$ page = $ _ Get ["page"];
$ eachpage = $ page_size;
$ pagesql = strstr ($ SQL, "from");
$ pagesql = "select count (*) as IDS ". $ pagesql;
$ conn = mysql_query ($ pagesql) or die (mysql_error ();
if ($ rs = mysql_fetch_array ($ conn )) $ sums = $ Rs [0];
$ pages = Ceil ($ sums-0.5 )/ $ Eachpage)-1;
$ pages = $ pages> = 0? $ Pages: 0;
$ prepage = ($ page> 0 )? $ Page-1: 0;
$ nextpage = ($ page <$ pages )? $ Page + 1: $ pages;
$ startpos = $ page * $ eachpage;
$ SQL. = "Limit $ startpos, $ eachpage";
}< br> // display page
function showpage ()
{< br> global $ page, $ pages, $ prepage, $ nextpage, $ querystring; // Param from genpage function
$ shownum = 10/2;
$ startpage = ($ page >=$ shownum )? $ Page-$ shownum: 0;
$ endpage = ($ page + $ shownum <= $ pages )? $ Page + $ shownum: $ pages;

echo "Total". ($ pages + 1). "Page:";
if ($ page> 0) echo " homepage ";
if ($ startpage> 0)
echo "... ? ";
for ($ I = $ startpage; $ I <= $ endpage; $ I ++)
{< br> if ($ I = $ page) echo " [". ($ I + 1 ). "] ";
else echo " ". ($ I + 1 ). "";
}< br> if ($ endpage <$ pages)
echo " ? ... ";
if ($ page <$ pages)
echo" last page ";
}< br> // display the page with classification
function showpage1 ()
{< br> $ fenlei =$ _ Get ["fenleiid"];
global $ page, $ pages, $ prepage, $ nextpage, $ querystring; // Param from genpage function
$ shownum = 10/2;
$ startpage = ($ page >=$ shownum )? $ Page-$ shownum: 0;
$ endpage = ($ page + $ shownum <= $ pages )? $ Page + $ shownum: $ pages;

Echo "Total". ($ pages + 1). "Page :";
If ($ page> 0) echo "<a href = $ php_self? Fenleiid = $ fenlei & page = 0 $ querystring> homepage </a> ";
If ($ startpage> 0)
Echo "... <B> <a href = $ php_self? Fenleiid = $ fenlei & page = ". ($ page-$ shownum * 2)." $ querystring>? </A> </B> ";
For ($ I = $ startpage; $ I <= $ endpage; $ I ++)
{
If ($ I = $ page) echo "<B> [". ($ I + 1). "] </B> ";
Else echo "<a href = $ php_self? Fenleiid = $ fenlei & page = $ I $ querystring> ". ($ I + 1)." </a> ";
}
If ($ endpage <$ pages)
Echo "<B> <a href = $ php_self? Fenleiid = $ fenlei & page = ". ($ page + $ shownum * 2)." $ querystring>? </A> </B> ...";
If ($ page <$ pages)
Echo "<a href = $ php_self? Fenleiid = $ fenlei & page = $ pages $ querystring> last page </a & amp; gt ;";
}
?>
2) Two Calls
First
<? PHP
$ SQL = "select * From liuyan order by ly_id DESC ";
Genpage ($ SQL); // you only need to add this line to the normal code.
$ Conn = mysql_query ($ SQL, $ connec );
While ($ rs = mysql_fetch_array ($ conn )){
?>
Second
<? PHP
}
?>
<? PHP
Showpage (); // display page
?>
<? PHP
Mysql_close ();
?>

4. server-side inclusion
<? PHP require_once ('conn. php');?>

5. How to Write a record to the database, and then prompt and jump to the page
<? PHP
$ Ly_title = $ _ post ["ly_title"];
$ Ly_content = $ _ post ["ly_content"];
$ Ly_time = $ _ post ["ly_time"];
$ Ly_author = $ _ post ["ly_author"];
$ Ly_email = $ _ post ["ly_email"];
$ SQL = "insert into liuyan (ly_title, ly_content, ly_time, ly_author, ly_email) values ('". $ ly_title. "','". $ ly_content. "','". $ ly_time. "','". $ ly_author. "','". $ ly_email. "')";
Mysql_query ($ SQL, $ connec );
Echo ("<SCRIPT type = 'text/JavaScript '> alert (' added successfully! '); Location. href = 'index. php'; </SCRIPT> ");
?>

6. A dialog box is displayed, and a page Jump occurs.
<? PHP
Echo ("<SCRIPT type = 'text/JavaScript '> alert (' added successfully! '); Location. href = 'index. php'; </SCRIPT> ");
?>

7. Information viewing page (conditional database READING)
1) conditional access to the database
<? PHP
$ SQL = "select * From liuyan where ly_id = $ _ Get [ID]";
$ Conn = mysql_query ($ SQL, $ connec );
$ Rs = mysql_fetch_array ($ conn );
?>
2) Output A Field
<? = $ Rs [ly_title]?>
3) shut down the database
<? PHP
Mysql_close ();
?>

8. Update a record in the database and prompt for redirection.
<? PHP
$ Ly_title = $ _ post ["ly_title"];
$ Ly_content = $ _ post ["ly_content"];
$ Ly_time = $ _ post ["ly_time"];
$ Ly_author = $ _ post ["ly_author"];
$ Ly_email = $ _ post ["ly_email"];
$ SQL = "Update liuyan set ly_title = '$ ly_title', ly_content = '$ ly_content', ly_time = '$ ly_time', ly_author = '$ ly_author ', ly_email = '$ ly_email' Where ly_id = $ _ Get [ID] ";
Mysql_query ($ SQL, $ connec );
Echo ("<SCRIPT type = 'text/JavaScript '> alert ('Update successful! '); Location. href =' ../index. php'; </SCRIPT> ");
?>

9. How to delete a record in a database
<? PHP
$ SQL = "delete from liuyan where ly_id = $ _ Get [ID]";
Mysql_query ($ SQL, $ connec );
Echo ("<SCRIPT type = 'text/JavaScript '> alert ('deleted successfully! '); Location. href =' ../index. php'; </SCRIPT> ");
?>

10. How to perform member login verification
<? PHP
Session_start ();
$ Username = $ _ post ["username"];
$ Password = $ _ post ["password"];
$ SQL = "select * from Admin where username = '". $ username. "' & Password = '". $ password ."'";
$ Result = mysql_query ($ SQL, $ connec );
If ($ ROW = mysql_fetch_array ($ result )){
Session_register ("admin ");
$ Admin = $ username;
Echo ("<SCRIPT type = 'text/JavaScript '> alert ('logon successful! '); Location. href = 'admin. php'; </SCRIPT> ");}
Else
{
Echo ("<SCRIPT type = 'text/JavaScript '> alert ('the user name or password you entered is incorrect. Please enter it again! '); Location. href = 'login. php'; </script & gt ;");
}
Mysql_close ();
?>

11. How to check the session (background check page creation)
<? PHP
Session_start ();
If (! Isset ($ _ session ["admin"]) {
Header ("Location: Login. php ");
Exit;
}
?>

12. Verify that the user name and password are filled in (JavaScript)
<Script language = JavaScript>
<! --
Function confirmlogin ()
{
If (document. frmmain. username. value. Length <4 | document. frmmain. username. value = "")
{
Document. frmmain. username. Focus ();
Document. frmmain. username. Select;
Window. Alert ("Enter your username! ");
Return false;
}
If (document. frmmain. Password. value. Length <4)
{
Document. frmmain. Password. Focus ();
Document. frmmain. Password. Select;
Window. Alert ("enter your password! ");
Return false;
}
Return true;
}
// -->
</SCRIPT>

13. Call the editor method in PHP
1) Place the Editor folder in the background management folder.
2) use the following statements to introduce data.
<Input name = "content" type = "hidden" value = ''>
<IFRAME id = "ewebeditor1" src = "ewebeditorphspo2/ewebeditor.htm? Id = content & Style = coolblue "frameborder =" 0 "scrolling =" no "width =" 550 "Height =" 350 "> </iframe>
Note: name of the folder in the ewebeditorphspo2 editor.
Id = content indicates the name of the hidden domain above.

14. loop output (which can be classified)
1) insert a row and a column of tables
<? PHP
$ I = 1;
?>
<Table>
<Tr>
<? PHP
While ($ rs = mysql_fetch_array ($ conn )){
?>
<TD>
Other cyclic tables and outputs
</TD>
<? PHP
If ($ I % 2 = 0 ){
Echo "</tr> <tr> ";
}
$ I ++;
}
?>
</Tr>
</Table>

15. Bind data to the drop-down list box (selected by default when modification is made)
<Select name = "fenleiid">
<? PHP
$ SQL = "select * From fenleibiao ";
$ Conn = mysql_query ($ SQL, $ connec );
While ($ RS1 = mysql_fetch_array ($ conn )){
?>
<Option value = "<? = $ RS1 ["fenleiid"]?> "
<?
If ($ Rs ["fenleiid"] = $ RS1 ["fenleiid"]) {
Echo "selected ";
}
?>
<? = $ RS1 ["flname"]?>
</Option>
<? Php>
}
?>
</SELECT>

16. Get the character length Function
Strlen ($ c)> 12

17. Define a character truncation Function
Usage: <? = Substrgb ($ Rs ["title"], 10)?>
Function substrgb ($ in, $ num ){
$ Pos = 0;
$ Out = "";
While ($ c = substr ($ in, $ POs, 1 )){
If ($ c = "\ n") break;
If (ord ($ c) & gt; 128 ){
$ Out. = $ C;
$ POS ++;
$ C = substr ($ in, $ POs, 1 );

$ Out. = $ C;
} Else {
$ Out. = $ C;
}
$ POS ++;
If ($ POS> = $ num) break;
}
If ($ out! = $ In) $ out = $ out ."...";
Return $ out;
}

18. Determine if it is a number
! Is_numeric (qq)

19. Obtain the current date in PHP Technology
$ Ptime = date ("Y-m-d ");

20. php verification used for user registration Program
If ($ admin = "" or (strlen ($ admin)> 16) or (strlen ($ admin) <2 )){
Echo "<script language = JavaScript> alert ('Enter the user name (cannot be greater than 16 or less than 2 )');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ Password = "" Or strlen ($ password)> 16 or strlen ($ password) <6 ){
Echo "<script language = JavaScript> alert ('password is 6-16 characters ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ Password = ""){
Echo "<script language = JavaScript> alert ('Confirm password cannot be blank ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
} Else {
If ($ password! = $ Password1 ){
Echo "<script language = JavaScript> alert ('inconsistent password with confirm password ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
}
If ($ Wt = ""){
Echo "<script language = JavaScript> alert ('password cannot be blank ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ da = ""){
Echo "<script language = JavaScript> alert ('answer cannot be blank ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";

}
If ($ QQ! = ""){
If (! Is_numeric ($ qq )){
Echo "<script language = JavaScript> alert ('qq number must be number ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
}
If ($ youbian = "" Or strlen ($ youbian )! = 6 ){
Echo "<script language = JavaScript> alert ('Enter the zip code correctly ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ youbian! = ""){
If (! Is_numeric ($ youbian )){
Echo "<script language = JavaScript> alert ('zip code must be a number ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
}
If ($ dizhi = ""){
Echo "<script language = JavaScript> alert ('address cannot be blank ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ mail = ""){
Echo "<script language = JavaScript> alert ('e-mail cannot be blank! ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ textarea = ""){
Echo "<script language = JavaScript> alert ('personal instructions cannot be blank! ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}
If ($ textarea = "" Or strlen (textarea)> 150 ){
Echo "<script language = JavaScript> alert ('personal Description: 150 characters ');";
Echo "This. Location. href = 'vbscript: history. Back () '; </SCRIPT> ";
}

24. Determine the output content to output other results
<? PHP
If ($ Rs ["active"] = 1 ){
Echo "<font color = '# ff0000'> activation </font> ";
} Else {
Echo "disabled ";
}
?>

25. Character truncation Function
<? = Substr ("$ Rs [zixun_biaoti]", 0, 28)?>

26. Male or single choice questions
<Input type = "radio" name = "hy_zhuangtai" value = "male" <? PHP if ($ Rs ["hy_zhungtai"] = "male") {echo "checked" ;}?>> Male
<Input type = "radio" name = "hy_zhuangtai" value = "" <? PHP if ($ Rs ["hy_zhuangtai"] = "") {echo "checked" ;}?>> Female

27. single choice without single answer

Lock
else {?>
unlock

its save page is

$ hy_id = $ _ Get ['id'];
$ action = $ _ Get ['action'];
if ($ action = 'yes') {
$ SQL = "Update hybiao set hy_zhuangtai = 'lock' where hy_id = '$ id '";
$ query = mysql_query ($ SQL, $ connec);
echo (" ");
}< br> else {
$ SQL = "Update hybiao set hy_zhuangtai = 'normal' where hy_id = '$ id '";
$ query = mysql_query ($ SQL, $ connec);
echo (" ");
}< br> mysql_close ();
?>

28. If the text is too long, the excessive text will be displayed as a ellipsis.
<Div style = "width: 120px; Height: 50px; Border: 0px solid blue; overflow: hidden; text-overflow: ellipsis">
<Nobr> for example, a row of text is long and cannot be displayed in a table. </nobr>
</Div>

29.
Prohibit copying, drag and select
<Body ondragstart = Window. event. returnvalue = false oncontextmenu = Window. event. returnvalue = false onselectstart = event. returnvalue = false>
30. Changes in large text and small text
<SCRIPT type = "text/JavaScript">
Function dozoom (size)
{Document. getelementbyid ('zoom '). style. fontsize = size + 'px ';}
</SCRIPT>
<Span id = "zoom"> text to be specified </span>
<A href = "javascript: dozoom (16)"> large </a> <a href = "javascript: dozoom (14) "> medium </a> <a href =" javascript: dozoom (12) "> small </a>

30. Add to favorites and set as Homepage
<A href = # onclick = "this. style. behavior = 'url (# default # homepage) '; this. setHomePage ('HTTP: // www.makewing.com/lanren/'); "> set as homepage </a>
<A href = "javascript: window. External. AddFavorite ('HTTP: // www.makewing.com/lanren/', 'Lazy gallery')"> Add to favorites </a>

31. Record and display the last modification time of the webpage
<Script language = JavaScript>
Document. Write ("Last Update time:" + document. lastmodified + "")
</SCRIPT>

32. Holiday countdown
<Script language = "JavaScript">
VaR TimeDate = new date ("October 1,2002 ");
VaR times = "National Day ";
VaR now = new date ();
VaR date = TimeDate. gettime ()-Now. gettime ();
VaR time = math. Floor (Date/(1000*60*60*24 ));
If (Time> = 0)
Document. Write ("now" + times + "and:" + time + "day ")
</SCRIPT>

33. Open a window to maximize
<Script language = "JavaScript">
<! -- Begin
Self. moveTo (0, 0)
Self. resizeTo (screen. availwidth, screen. availheight)
// End -->
</SCRIPT>

34. Add background music
<Bgsound src = "mid/windblue [1]. Mid" loop = "-1"> only applicable to IE
<Embed src = "music. Mid" autostart = "true" loop = "true" hidden = "true"> applicable to both Netscape and IE

35. Scroll
<Marquee direction = up Height = 146 onmouseout = start () onmouseover = stop () scrollamount = 2>
Scroll Information
</Marquee>

36. When you click an empty link, the page is often reset to the top.
The Code "javascript: void (null)" replaces the original "#" mark

37. You cannot right-click it, or press Ctrl + A to copy it!
<Body oncontextmenu = "window. event. returnvalue = false"
Onkeypress = "window. event. returnvalue = false"
Onkeydown = "window. event. returnvalue = false"
Onkeyup = "window. event. returnvalue = false"
Ondragstart = "window. event. returnvalue = false"
Onselectstart = "event. returnvalue = false">
</Body>

37. Random conversion of background images (a special effect that refreshes the mood)
<Script language = "JavaScript">
Image = new array (4); // defines the image as an array of the number of images.
Image [0] = 'tu0.gif '// path of the background image
Image [1] = 'tu1.gif'
Image [2] = 'tu2.gif'
Image [3] = 'tu3.gif'
Image [4] = 'tu4.gif'
Number = math. Floor (math. Random () * image. Length );
Document. Write ("<body background =" + image [number] + "> ");
</SCRIPT>

38. Move the mouse over the link
Style = "cursor: hand"

39. How to close the Layer
<Div id = "layer1"> </div>
<A href = "#" onclick = "layer1.style. Display = 'none'"> close layer </a>

40. <a href = javascript: Close ()> [close the window] </a>

41. The concave text background is gray
<Div style = "width: 300px; padding: 20px; overflow: hidden; Word-wrap: Break-word; Word-break: Break: All; font-size: 12px; line-Height: 18px; Background-color: # eeeeee; ">
<Font disabled>
How are you doing? <Br>
Don't you want to try it? <Br>
<A href = "www. lenvo. cnhttp: // www.lenvo.cn/"> www.lenvo.cn </a> </font>
</Div>

42. link the table
<Table width = "100%" onclick = "window. Open ('HTTP: // www.makewing.com/',' _ blank ')" style = "cursor: Hand">
<Tr>
<TD Height = "100" bgcolor = "f4f4f4"> </TD>
</Tr>
</Table>

43. Back & close the window
Back: javascript: history. Back (1)
Close: javascript: window. Close ();

44. If the text is too long, the excessive text will be displayed as a ellipsis.
<Div style = "width: 120px; Height: 50px; Border: 0px solid blue; overflow: hidden; text-overflow: ellipsis">
<Nobr> for example, a row of text is long and cannot be displayed in a table. </nobr>
</Div>

45. prohibit copying. Drag and select