db_mysql.php

<?php

class DB_MySQL {





  /* public: connection parameters */


  var $Host     = "";


  var $Database = "";


  var $User     = "";


  var $Password = "";


  var $Persistent = false;





  /* public: configuration parameters */


  var $Auto_Free     = 0;     ## Set to 1 for automatic mysql_free_result()


  var $Debug         = 0;     ## Set to 1 for debugging messages.


  var $Halt_On_Error = "yes"; ## "yes" (halt with message), "no" (ignore errors quietly), "report" (ignore errror, but spit a warning)


  var $Seq_Table     = "db_sequence";





  /* public: result array and current row number */


  var $Record   = array();


  var $Row;





  /* public: current error number and error text */


  var $Errno    = 0;


  var $Error    = "";





  /* public: this is an api revision, not a CVS revision. */


  var $type     = "mysql";


  var $revision = "1.2";





  /* private: link and query handles */


  var $Link_ID  = 0;


  var $Query_ID = 0;











  /* public: constructor */


  function DB_Sql($query = "") {


      $this->query($query);


  }





  /* public: some trivial reporting */


  function link_id() {


    return $this->Link_ID;


  }





  function query_id() {


    return $this->Query_ID;


  }





  function try_connect($Host = "", $User = "", $Password = "") {


    /* Handle defaults */


    if ("" == $Host)      $Host     = $this->Host;


    if ("" == $User)      $User     = $this->User;


    if ("" == $Password)  $Password = $this->Password;





    if($this->Persistent)


      $this->Link_ID = @mysql_pconnect($Host, $User, $Password);


    else


      $this->Link_ID = @mysql_connect($Host, $User, $Password);





    $is_connect = $this->Link_ID ? true : false;





    return $is_connect;


  }





  /* public: connection management */


  function connect($Database = "", $Host = "", $User = "", $Password = "") {


    /* Handle defaults */


    if ("" == $Database)


      $Database = $this->Database;


    if ("" == $Host)


      $Host     = $this->Host;


    if ("" == $User)


      $User     = $this->User;


    if ("" == $Password)


      $Password = $this->Password;





    /* establish connection, select database */


    if ( 0 == $this->Link_ID ) {





      if($this->Persistent)


        $this->Link_ID=mysql_pconnect($Host, $User, $Password);


      else


        $this->Link_ID=mysql_connect($Host, $User, $Password);





      if (!$this->Link_ID) {


        $this->halt("pconnect($Host, $User, \$Password) failed.");


        return 0;


      }





      if (!@mysql_select_db($Database,$this->Link_ID)) {


        $this->halt("cannot use database ".$this->Database);


        return 0;


      }


    }





    return $this->Link_ID;


  }





  /* public: discard the query result */


  function free() {


      @mysql_free_result($this->Query_ID);


      $this->Query_ID = 0;


  }





  /* public: perform a query */


  function query($Query_String) {


    /* No empty queries, please, since PHP4 chokes on them. */


    if ($Query_String == "")


      /* The empty query string is passed on from the constructor,


       * when calling the class without a query, e.g. in situations


       * like these: '$db = new DB_Sql_Subclass;'


       */


      return 0;





    if (!$this->connect()) {


      return 0; /* we already complained in connect() about that. */


    };





    # New query, discard previous result.


    if ($this->Query_ID) {


      $this->free();


    }





    if ($this->Debug)


      printf("Debug: query = %s<br>\n", $Query_String);





    $this->Query_ID = @mysql_query($Query_String,$this->Link_ID);


    $this->Row   = 0;


    $this->Errno = mysql_errno();


    $this->Error = mysql_error();


    if (!$this->Query_ID) {


      $this->halt("Invalid SQL: ".$Query_String);


    }





    # Will return nada if it fails. That's fine.


    return $this->Query_ID;


  }





  /* public: walk result set */


  function next_record() {


    if (!$this->Query_ID) {


      $this->halt("next_record called with no query pending.");


      return 0;


    }





    $this->Record = @mysql_fetch_array($this->Query_ID);


    $this->Row   += 1;


    $this->Errno  = mysql_errno();


    $this->Error  = mysql_error();





    $stat = is_array($this->Record);


    if (!$stat && $this->Auto_Free) {


      $this->free();


    }


    return $stat;


  }





  /* public: position in result set */


  function seek($pos = 0) {


    $status = @mysql_data_seek($this->Query_ID, $pos);


    if ($status)


      $this->Row = $pos;


    else {


      $this->halt("seek($pos) failed: result has ".$this->num_rows()." rows");





      /* half assed attempt to save the day,


       * but do not consider this documented or even


       * desireable behaviour.


       */


      @mysql_data_seek($this->Query_ID, $this->num_rows());


      $this->Row = $this->num_rows;


      return 0;


    }





    return 1;


  }





  /* public: table locking */


  function lock($table, $mode="write") {


    $this->connect();





    $query="lock tables ";


    if (is_array($table)) {


      while (list($key,$value)=each($table)) {


        if ($key=="read" && $key!=0) {


          $query.="$value read, ";


        } else {


          $query.="$value $mode, ";


        }


      }


      $query=substr($query,0,-2);


    } else {


      $query.="$table $mode";


    }


    $res = @mysql_query($query, $this->Link_ID);


    if (!$res) {


      $this->halt("lock($table, $mode) failed.");


      return 0;


    }


    return $res;


  }





  function unlock() {


    $this->connect();





    $res = @mysql_query("unlock tables");


    if (!$res) {


      $this->halt("unlock() failed.");


      return 0;


    }


    return $res;


  }








  /* public: evaluate the result (size, width) */


  function affected_rows() {


    return @mysql_affected_rows($this->Link_ID);


  }





  function num_rows() {


    return @mysql_num_rows($this->Query_ID);


  }





  function num_fields() {


    return @mysql_num_fields($this->Query_ID);


  }





  /* public: shorthand notation */


  function nf() {


    return $this->num_rows();


  }





  function np() {


    print $this->num_rows();


  }





  function f($Name) {


    return isset($this->Record[$Name]) ? $this->Record[$Name] : "";


  }





  function p($Name) {


    print $this->Record[$Name];


  }





  /* public: sequence numbers */


  function nextid($seq_name) {


    $this->connect();





    if ($this->lock($this->Seq_Table)) {


      /* get sequence number (locked) and increment */


      $q  = sprintf("select nextid from %s where seq_name = '%s'",


                $this->Seq_Table,


                $seq_name);


      $id  = @mysql_query($q, $this->Link_ID);


      $res = @mysql_fetch_array($id);





      /* No current value, make one */


      if (!is_array($res)) {


        $currentid = 0;


        $q = sprintf("insert into %s values('%s', %s)",


                 $this->Seq_Table,


                 $seq_name,


                 $currentid);


        $id = @mysql_query($q, $this->Link_ID);


      } else {


        $currentid = $res["nextid"];


      }


      $nextid = $currentid + 1;


      $q = sprintf("update %s set nextid = '%s' where seq_name = '%s'",


               $this->Seq_Table,


               $nextid,


               $seq_name);


      $id = @mysql_query($q, $this->Link_ID);


      $this->unlock();


    } else {


      $this->halt("cannot lock ".$this->Seq_Table." - has it been created?");


      return 0;


    }


    return $nextid;


  }





  /* public: return table metadata */


  function metadata($table='',$full=false) {


    $count = 0;


    $id    = 0;


    $res   = array();





    /*


     * Due to compatibility problems with Table we changed the behavior


     * of metadata();


     * depending on $full, metadata returns the following values:


     *


     * - full is false (default):


     * $result[]:


     *   [0]["table"]  table name


     *   [0]["name"]   field name


     *   [0]["type"]   field type


     *   [0]["len"]    field length


     *   [0]["flags"]  field flags


     *


     * - full is true


     * $result[]:


     *   ["num_fields"] number of metadata records


     *   [0]["table"]  table name


     *   [0]["name"]   field name


     *   [0]["type"]   field type


     *   [0]["len"]    field length


     *   [0]["flags"]  field flags


     *   ["meta"][field name]  index of field named "field name"


     *   The last one is used, if you have a field name, but no index.


     *   Test:  if (isset($result['meta']['myfield'])) { ...


     */





    // if no $table specified, assume that we are working with a query


    // result


    if ($table) {


      $this->connect();


      $id = @mysql_list_fields($this->Database, $table);


      if (!$id)


        $this->halt("Metadata query failed.");


    } else {


      $id = $this->Query_ID;


      if (!$id)


        $this->halt("No query specified.");


    }





    $count = @mysql_num_fields($id);





    // made this IF due to performance (one if is faster than $count if's)


    if (!$full) {


      for ($i=0; $i<$count; $i++) {


        $res[$i]["table"] = @mysql_field_table ($id, $i);


        $res[$i]["name"]  = @mysql_field_name  ($id, $i);


        $res[$i]["type"]  = @mysql_field_type  ($id, $i);


        $res[$i]["len"]   = @mysql_field_len   ($id, $i);


        $res[$i]["flags"] = @mysql_field_flags ($id, $i);


      }


    } else { // full


      $res["num_fields"]= $count;





      for ($i=0; $i<$count; $i++) {


        $res[$i]["table"] = @mysql_field_table ($id, $i);


        $res[$i]["name"]  = @mysql_field_name  ($id, $i);


        $res[$i]["type"]  = @mysql_field_type  ($id, $i);


        $res[$i]["len"]   = @mysql_field_len   ($id, $i);


        $res[$i]["flags"] = @mysql_field_flags ($id, $i);


        $res["meta"][$res[$i]["name"]] = $i;


      }


    }





    // free the result only if we were called on a table


    if ($table) @mysql_free_result($id);


    return $res;


  }





  /* private: error handling */


  function halt($msg) {


    $this->Error = @mysql_error($this->Link_ID);


    $this->Errno = @mysql_errno($this->Link_ID);


    if ($this->Halt_On_Error == "no")


      return;





    $this->haltmsg($msg);





    if ($this->Halt_On_Error != "report")


      die("Session halted.");


  }





  function haltmsg($msg) {


    printf("</td></tr></table><b>Database error:</b> %s<br>\n", $msg);


    printf("<b>MySQL Error</b>: %s (%s)<br>\n",


      $this->Errno,


      $this->Error);


  }





  function table_names() {


    $this->query("SHOW TABLES");


    $i=0;


    while ($info=mysql_fetch_row($this->Query_ID))


     {


      $return[$i]["table_name"]= $info[0];


      $return[$i]["tablespace_name"]=$this->Database;


      $return[$i]["database"]=$this->Database;


      $i++;


     }


   return $return;


  }


}





//End DB MySQL Class








?>