/includes/db_mysql.inc

<?php

/*

 * Session Management for PHP3

 *

 * Copyright (c) 1998-2000 NetUSE AG

 *                    Boris Erdmann, Kristian Koehntopp

 *

 * $Id: db_mysql.inc,v 1.11 2002/08/07 19:33:57 layne_weathers Exp $

 *

 */ 



class DB_Sql {

  

  /* public: connection parameters */

  var $Host     = "";

  var $Database = "";

  var $User     = "";

  var $Password = "";



  /* 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 $PConnect      = 0;     ## Set to 1 to use persistent database connections

  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;



  var $locked   = false;      ## set to true while we have a lock



  /* 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;

  }



  /* 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->PConnect) {

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

      } else {

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

      }

      if (!$this->Link_ID) {

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

        return 0;

      }



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

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

    $query = "lock tables ";

    if(is_array($table)) {

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

        // text keys are "read", "read local", "write", "low priority write"

        if(is_int($key)) $key = $mode;

        if(strpos($value, ",")) {

          $query .= str_replace(",", " $key, ", $value) . " $key, ";

        } else {

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

        }

      }

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

    } elseif(strpos($table, ",")) {

      $query .= str_replace(",", " $mode, ", $table) . " $mode";

    } else {

      $query .= "$table $mode";

    }

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

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

      return false;

    }

    $this->locked = true;

    return true;

  }

  

  function unlock() {



    // set before unlock to avoid potential loop

    $this->locked = false;



    if(!$this->query("unlock tables")) {

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

      return false;

    }

    return true;

  }



  /* 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) {

    if (isset($this->Record[$Name])) {

      return $this->Record[$Name];

    }

  }



  function p($Name) {

    if (isset($this->Record[$Name])) {

      print $this->Record[$Name];

    }

  }



  /* public: sequence numbers */

  function nextid($seq_name) {

    /* if no current lock, lock sequence table */

    if(!$this->locked) {

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

        $locked = true;

      } else {

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

        return 0;

      }

    }

    

    /* get sequence number and increment */

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

               $this->Seq_Table,

               $seq_name);

    if(!$this->query($q)) {

      $this->halt('query failed in nextid: '.$q);

      return 0;

    }

    

    /* No current value, make one */

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

      $currentid = 0;

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

                 $this->Seq_Table,

                 $seq_name,

                 $currentid);

      if(!$this->query($q)) {

        $this->halt('query failed in nextid: '.$q);

        return 0;

      }

    } else {

      $currentid = $this->f("nextid");

    }

    $nextid = $currentid + 1;

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

               $this->Seq_Table,

               $nextid,

               $seq_name);

    if(!$this->query($q)) {

      $this->halt('query failed in nextid: '.$q);

      return 0;

    }

    

    /* if nextid() locked the sequence table, unlock it */

    if($locked) {

      $this->unlock();

    }

    

    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"

     *   This last one could be 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.");

        return false;

      }

    } else {

      $id = $this->Query_ID; 

      if (!$id) {

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

        return false;

      }

    }

 

    $count = @mysql_num_fields($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;

  }



  /* public: find available table names */

  function table_names() {

    $this->connect();

    $h = @mysql_query("show tables", $this->Link_ID);

    $i = 0;

    while ($info = @mysql_fetch_row($h)) {

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

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

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

      $i++;

    }

    

    @mysql_free_result($h);

    return $return;

  }



  /* private: error handling */

  function halt($msg) {

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

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



    if ($this->locked) {

      $this->unlock();

    }



    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);

  }



}

?>