Snippets Databases
Databases
EasyDatabase
by: umut
|
October 7, 2002
Version: 1.02
Type: Class
Category: Databases
License: GNU General Public License
Description: Handling several databases at he same time easily
<?
//==========================================================================================
// By Umut Isik from Mavi Software Corporation
// umut@mavibilgisayar.com
//
// I am waiting for your suggestions.The description of the object and functions are below the code
//
//
// NOT : The usage of the insert() function is a bit different.Please read carefully.
// and mail if needed.
//
//
//==========================================================================================
class database {
var $database;
var $link;
var $table_num;
var $tables= array();
function show() {
$db=$this->database;
$tables=$this->table_num;
echo("Database: $db<br>There are $tables tables :<br>");
for($i=0;$i<$this->table_num;$i++) {
$tr=$this->tables[$i];
echo("$tr <br>");
}
}
function construct($str,$link) {
$this->link=$link;
$db_list=mysql_list_dbs($this->link);
$flag=0;
while($row=mysql_fetch_object($db_list)) {
if($row->Database==$str) $flag=1;
}
if($flag==0) {
echo("<p><b>Error in function construct().<br>");
echo("No such database named $str.<b></p>");
exit();
}
else
$this->database=$str;
$tables_query=mysql_list_tables($this->database);
$i=0;
while(list($table)=mysql_fetch_row($tables_query)) {
$this->tables[$i]=$table;
$i++;
}
$this->table_num=$i;
mysql_select_db($str,$this->link);
}
function insert($table,$field_names,$values) {
mysql_select_db($this->database,$this->link);
$db_list=mysql_list_dbs($this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function insert().<br>");
echo("There exist no table named $table in $this->database</b></p>");
exit();
}
$fields=explode(",",$field_names);
$values=explode("~@",$values);
//This part is the most important part.While making the $values by the valu
//es you must use an identifier.Be carefull not to use an identifier that
//can be in a normal string.I offer using "~@"
if(count($fields)!=count($values)) {
echo("<p><b>Error in function insert().<br>");
echo("Invalid number of arguments</b></p>");
exit();
}
$i=0;
$res=mysql_query("select * from $table");
$res_num=mysql_num_fields($res);
while($i<$res_num) {
$table_field_names[$i]=mysql_field_name($res,$i);
$i++;
}
$i=0;
while($fields[$i]) {
if(!in_array($fields[$i],$table_field_names)) {
echo("<p><b>Error in function insert().<br>");
echo("Error in field names argument (second argument of the function)");
echo("There exist no field named $fields[$i] in table $table of $this->database<b></p>");
//echo $table_names[$i];
exit();
}
$i++;
}
$query="INSERT INTO $table ";
$i=0;
while($fields[$i]) {
if($i==0) {
$field_string=$fields[$i];
$values_string="'".$values[$i]."'";
}
else {
$field_string=$field_string.",".$fields[$i];
$values_string=$values_string.",'".$values[$i]."'";
}
$i++;
}
$query=$query."(".$field_string.")"." VALUES (".$values_string.")";
mysql_query($query);
}
function select($table,$field_names,$additional_rules) { //strings with no braces
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function select().<br>");
echo("Error there exist no table named $table in $this->database</b></p>");
exit();
}
if($field_names!="*") {
$fields=explode(",",$field_names);
$i=0;
$res=mysql_query("select * from $table");
$res_num=mysql_num_fields($res);
while($i<$res_num) {
$table_field_names[$i]=mysql_field_name($res,$i);
$i++;
}
$i=0;
while($fields[$i]) {
if(!in_array($fields[$i],$table_field_names)) {
echo("<p><b>Error in function select().<br>");
echo("Error in field names argument (second argument of the function)");
echo("There exist no field named $fields[$i] in table $table of $this->database</b></p>");
//echo $table_names[$i];
exit();
}
$i++;
}
}
if($additional_rules)
$query="SELECT ".$field_names." FROM ".$table." WHERE ".$additional_rules;
else
$query="SELECT ".$field_names." FROM ".$table;
$result=mysql_query($query);
$i=0;
while($row=mysql_fetch_array($result)) {
$array[$i]=$row;
$i++;
}
return $array;
}
function update($table,$field_names,$values,$additional_rules) {
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function update().<br>");
echo("Error there exist no table named $table in $this->database</b></p>");
exit();
}
$fields=explode(",",$field_names);
$values=explode("~@",$values);
//This part is the most important part.While making the $values by the valu
//es you must use an identifier.Be carefull not to use an identifier that
//can be in a normal string.I offer using "~@"
if(count($fields)!=count($values)) {
echo("<p><b>Error in function update().<br>");
echo("Error invalid number of argiments</b></p>");
exit();
}
$i=0;
$res=mysql_query("select * from $table");
$res_num=mysql_num_fields($res);
while($i<$res_num) {
$table_field_names[$i]=mysql_field_name($res,$i);
$i++;
}
$i=0;
$num=count($fields);
while($fields[$i]) {
if(!in_array($fields[$i],$table_field_names)) {
echo("<p><b>Error in function update().<br>");
echo("Error in field names argument (second argument of the update function)");
echo("There exist no field named $fields[$i] in table $table of $this->database<b></p>");
//echo $table_names[$i];
exit();
}
if($i==0) $and="";
else $and=",";
if(($values[$i][0]=="+") || ($values[$i][0]=="-") )
$update_str=$update_str." $and ".$fields[$i]."=".$fields[$i].$values[$i];
else
$update_str=$update_str." $and ".$fields[$i]."='".$values[$i]."'";
$i++;
}
$query="UPDATE ".$table." SET ".$update_str;
if($additional_rules) $query=$query." WHERE ".$additional_rules;
mysql_query($query);
}
function remove ($table,$additional_rules) {
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function remove().<br>");
echo("Error there exist no table named $table in $this->database</b></p>");
exit();
}
$query="DELETE FROM ".$table." WHERE ".$additional_rules;
mysql_query($query);
}
function field_name($table,$index) {
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function field_name().<br>");
echo("Error there exist no table named $table in $this->database</b></p>");
exit();
}
$fields=mysql_list_fields("$this->database","$table",$this->link);
return mysql_field_name($fields,$i);
}
function field_num($table) {
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function field_num().<br>");
echo("Error there exist no table named $table in $this->database</b></p>");
exit();
}
$fields=mysql_list_fields("$this->database","$table",$this->link);
return mysql_num_fields($fields);
}
function field_names($table) {
mysql_select_db($this->database,$this->link);
if(!in_array($table,$this->tables)) {
echo("<p><b>Error in function field_names().<br>");
echo("Error there exist no table named $table in $this->database<br></p>");
exit();
}
$fields=mysql_list_fields("$this->database","$table",$this->link);
$columns=mysql_num_fields($fields);
for ($i=0;$i<$columns;$i++)
$fields_array[$i]=mysql_field_name($fields,$i);
return $fields_array;
}
function insert_id() {
return mysql_insert_id();
}
}
//==========================================================================================
// This library helps you to make several database connections and to handle database operations
// at the same time.The functions are explained below.
//
// 1) show() takes no arguments and prints the information of the object(The name of the db and the names of tables
// 2) construct() takes two arguments.The name of the database and MySQL link identifier of the connection.It constructs the
// object.
// 3) insert() takes three arguments.The name of the table , the field names and the field values.The field names and the
// field values must be string type.
// For example:
// insert("table_name","field1,field2,field3","value1i~@value2~@value3")
// !!!Separating the values with "~@" is important.You may use a different separator.
// !!!You have to modify insert function.The place is signed.
//
//
// 4) select() takes three arguments.The name of the table , the field names and the rules for selecting.
// This function returns an array pointer (The number os selected fields times the number of rows.
// For example :
// select("table_name","field1,field2,field3","field4='1' AND ....");
// select("table_name","*","field4='1' AND ....");
// 5) update() takes four arguments.The name of the table , the field names , the field values and the rules for updating
// For example :
// update("tablename","field1,field2,field3","v1~@+v2~@-v3","field4='1'");
// v1 sets the field1 value to v1
// +v2 increments field2 by v2
// -v3 decrements field3 by v3
// !!!Separating the values with "~@" is important.You may use a different separator.
// !!!You have to modify insert function.The place is signed.
//
// 6) remove() takes two arguments.The name of the table and the rules for deleting.For example
// remove("table_name","field='1' AND ....");
// 7) field_name() takes two arguments.The name of the table and the index of the field.It returns the name of the field
// with the index in the table.
// 8) field_num() returns the number of field in the table.
// 9) field_names() returns an array of the names of the fields of the table
// 10) insert_id() returns the id of the last insertion operation.
//
//
//
//
//============Example===========================================
//<?
//$link=mysql_connect("localhost","root","password");
//
//$db1=new database; //creating a new object
//$db1->construct("db1",$link); //constructing the connections
//
//$db2=new database; //creating a new object
//$db2->construct("db2",$link); //constructing the connections
//
//$array=$db1->field_names("table1");
//$i=0;
//while($array[$i])
// echo $array[$i]."<br>";
//
//echo $db2->field_name("table1",0);
//$db1->insert("table1","field1,field2","v1,v2");
//?>
//==========================================================================================
?>
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