A simple integrated class of database connection and text cache

A simple integrated class of database connection and text cache

The database connection and text cache are encapsulated in a class. Class Db { Protected $ _ connect; Protected $ _ db = Array (); Protected $ _ cache = Array (); Public function _ construct ($ args ){ List ($ this-> _ db, $ this-> _ cache) = $ args; } Protected function connect ($ db ){ $ This-> _ connect = mysql_connect ($ db ['hostname'], $ db ['username'], $ db ['password']); Mysql_set_charset ('utf8 '); Mysql_select_db ($ db ['databasename '], $ this-> _ connect ); } /** * Function: obtain the table data and format the queried data. the returned format is an array! * $ SQL: the input SQL statement to be executed, which must be SELECT * */ Public function fetch ($ SQL ){ $ Result = ''; If (isset ($ this-> _ cache ['expire ']) { $ Name = md5 (strtolower (str_replace ('','', $ SQL ))); $ Dir = substr ($ name, 0, 2 ); $ Dir = $ this-> _ cache ['dir']. '/'. $ dir; ! Is_dir ($ dir) & mkdir ($ dir, 0777 ); ! Is_dir ($ dir) & mkdir ($ dir, 0777 ); $ This-> _ cache ['path'] = $ dir. '/'. $ name; If (is_file ($ this-> _ cache ['path']) & $ this-> check_expire ()){ $ Result = $ this-> get (); } } If ($ result = ''){ $ Data = $ this-> exec ($ SQL ); $ Result = Array (); While ($ result [] = mysql_fetch_array ($ data, MYSQL_ASSOC) {}// remove the index Mysql_free_result ($ data ); Array_pop ($ result ); Isset ($ this-> _ cache ['expire ']) & $ this-> write ($ result ); } Return $ result; } /** * Function: execute all SQL statements, but not SELECT! * $ SQL: the input SQL statement to be executed. it cannot be a SELECT statement. * Return value: TRUE OR FALSE */ Public function exec ($ SQL ){ If ($ this-> _ connect === null) $ this-> connect ($ this-> _ db); // data link If ($ result = mysql_query ($ SQL, $ this-> _ connect )){ Return $ result; } Else { Die ("{$ SQL} Execution error: ". mysql_error ()); } } /** * Function: execute the database INSERT statement. it can only be an INSERT statement! * $ V: The input condition to be executed. in the array format, table indicates the table to be inserted, row indicates the field, and value indicates the value to be inserted. * Return value: mysql_insert_id () OR FALSE */ Public function insert ($ table, $ field, $ ignore = 0 ){ $ D = Array ('field' => '', 'Val' => ''); Foreach ($ field AS $ key => $ v ){ $ D ['field']. = $ key .','; $ D ['Val']. = "'{$ this-> escape ($ v )}',"; } $ D ['field'] = rtrim ($ D ['field'], ','); $ D ['Val'] = rtrim ($ D ['Val'], ','); $ Ignore = $ ignore> 0? 'Ignore ':''; $ SQL = "INSERT {$ ignore} INTO {$ this-> _ db ['perfix']} {$ table} ({$ D ['field']}) VALUES ({$ D ['Val']}) "; If ($ this-> exec ($ SQL )){ $ Insert_id = mysql_insert_id (); Return is_numeric ($ insert_id )? $ Insert_id: TRUE; } Else { Return FALSE; } } Public function update ($ table, $ field ){ $ D = Array ('where' => '', 'str' => ''); $ Index = 0; Foreach ($ field AS $ key => $ v ){ $ Index = 0? $ D ['where'] = "{$ key} = '{$ this-> escape ($ v)}'": $ D ['str']. = "{$ key} = '{$ this-> escape ($ v )}',"; $ Index ++; } $ D ['str'] = rtrim ($ D ['str'], ','); $ SQL = "UPDATE {$ this-> _ db ['perfix']} {$ table} SET {$ D ['str']} WHERE {$ D ['where' ]} "; Return $ this-> exec ($ SQL ); } Public function delete ($ table, $ field ){ $ Str = ''; Foreach ($ field AS $ key => $ v ){ $ Str = "{$ key} = '{$ v }'"; } $ SQL = 'delete from'. $ this-> _ db ['perfix']. $ table. 'where'. $ str. 'limit 1 '; Return $ this-> exec ($ SQL ); } Public function sum ($ table, $ condition ){ $ Totle = $ this-> fetch ('SELECT COUNT (*) AS totle FROM '. $ this-> _ db ['perfix']. $ table. 'Where '. $ condition ); Return $ totle [0] ['totle ']; } /** * Function: filter out special characters. * $ V: parameters to be passed in for detection * Return value: the detected parameter. */ Public function escape ($ v ){ Return mysql_real_escape_string ($ v ); } /* * Function: determines the cache. */ Public function cache ($ name, $ expire = 100000000 ){ $ This-> _ cache ['expire '] = $ expire; Return $ this; } Public function check_expire (){ Return (filemtime ($ this-> _ cache ['path']) + $ this-> _ cache ['expire '])> strtotime ("now "); } Public function write ($ data ){ $ F = fopen ($ this-> _ cache ['path'], 'w '); If ($ f ){ Flock ($ f, LOCK_EX ); Fseek ($ f, 0 ); Ftruncate ($ f, 0 ); $ Tmp = fwrite ($ f, serialize ($ data )); If (! ($ Tmp = false )){ $ Result = true; } Fclose ($ f ); } Chmod ($ this-> _ cache ['path'], 0777 ); } Public function get (){ $ F = fopen ($ this-> _ cache ['path'], 'r '); $ Data = fread ($ f, filesize ($ this-> _ cache ['path']); Fclose ($ f ); Return unserialize ($ data ); } Public function delete_dir ($ dir = ''){ $ Dir = empty ($ dir )? $ This-> _ cache ['dir']: $ dir; ! Is_dir ($ dir) & exit; $ D = opendir ($ dir ); $ I = 0; While ($ file = readdir ($ d ))! = False ){ $ Path = $ dir. '/'. $ file; If ($ I> 1) is_file ($ path )? Unlink ($ path): $ this-> delete_dir ($ path ); $ I ++; } Closedir ($ d ); Rmdir ($ dir ); } Public function _ destruct (){ Isset ($ this-> _ connect) & mysql_close ($ this-> _ connect ); } }