PHP and MySQL

One: Link database

　　mysql_connect  die　　("Connection database Failed");  mysql_pconnect(); // Persistent Links

Two: Select the database:

　　mysql_select_db ("MySQLdb") or Die ("Database selection failed");

Three: Splicing database

　　$sql= "SELECT * From ...";

Four: Execution database:

　　$result=$mysql _query($sql);

Five: Judging whether it is wrong:

1. Mysql_errno (); Error number// 2.mysql_error(); error message  if(! 　　　　Result) {  echo "1. Error number, 2. Error message";　　 exit; }

Six: Remove the record from the result set:

1. Non-select:

A. Get the number of lines that grow automatically:

　　　　　　mysql_insert_id // INSERT INTO (only used in tables with autogrow)

B. Getting the number of rows affected:

　　　　　　mysql_affected_rows (); // you can tell if the record changes, change the value, do not change the value if　　　　　　(mysql_affected_rows() > 0"execution success <br>";　　　　　　}Else{  echo "does not change record <br>"; }　　　　　　

2.select: Remove the record from the result set:

　　Mysql_fetch_row　　　($result);  // returns an indexed array of Mysql_fetch_assoc($result);     // returns an associative array (subscript: is the list) Mysql_fetch_array　　 　($result); // returns an index and associates an array of two Mysql_fetch_object　($result);   // returns a record as an object　　　　　　　

 　　  while($data=Mysql_fetch_row($result)) {Print_r($data); Echo"<br>"; } while($data=Mysql_fetch_assoc($result)) {Print_r($data); Echo"<br>"; }Mysql_data_seek($result, 3);//move the pointer, starting from the third one; 　　  while($data=Mysql_fetch_object($result)) {Print_r($data); Echo"<br>"; }

 　　 Echo"<table align= ' center ' width= ' border= ' 1 ' >"; Echo"<caption>;  while($row=Mysql_fetch_assoc($result)){          Echo"<tr>"; foreach($row  as $val){          Echo"<td>".$val." </td> "; Echo"</tr>"; }Echo"</table>";

3. Get field information:

A. Getting the information for a column:

　　　　Mysql_num_fields ($result);  // number of columns; mysql_num_rows ($result);  // number of rows; Mysql_field_name ($result,$i// Gets the name of the data field; $result:   result set  $i  : The first few columns　　　　　　　　　　　　　　

Eight: Release result set:

Mysql_free_resutl ($result);

    $link=mysql_connect("localhost", "root", "") or die("No Value selection"); mysql_select_db("Sqldb") or die("No database you want to select"); $sql= "SELECT * FROM Products"; $result=mysql_query($sql); if(!$result){        Echo Mysql_errno()." <br> ".Mysql_error(); }    Echo"<table align= ' center ' border= ' 1 ' >";  for($i= 0;$i<mysql_num_rows($result);$i++){        Echo"<th>" [email protected]Mysql_field_name($result,$i)." </th> "; }     while($row=Mysql_fetch_assoc($result)){        Echo"<tr>"; foreach($row  as $val){         Echo"<td>".$val." </td> "; }        Echo"</tr>"; }    Echo"<td colspan= ' 7 ' align= ' Right ' > column:".Mysql_num_fields($result)." Line: ".mysql_num_rows($result)." </td> "; Echo"<table>";

Nine: Close connection:

Close ()