AwlDBDialect.php

<?php
 
if ( !defined('E_USER_ERROR') ) define('E_USER_ERROR',256);

class AwlDBDialect {

  protected $dialect;

  protected $db;

  private $version;


  const HttpDateFormat = "'Dy, DD Mon IYYY HH24:MI:SS \"GMT\"'";

  const SqlDateFormat = "'YYYYMMDD\"T\"HH24MISS'";

  const SqlUTCFormat = "'YYYYMMDD\"T\"HH24MISS\"Z\"'";

  const SqlDurationFormat = "'\"PT\"HH24\"H\"MI\"M\"'";

  function __construct( $connection_string, $dbuser=null, $dbpass=null, $options=null ) {
    if ( preg_match( '/^(pgsql):/', $connection_string, $matches ) ) {
      $this->dialect = $matches[1];
    }
    else {
      error_log("Unable to connect to database: ". $e->getMessage() );
      trigger_error("Unsupported database connection '".$connection_string."'",E_USER_ERROR);
    }
    try {
      $this->db = new PDO( $connection_string, $dbuser, $dbpass, $options );
    } catch (PDOException $e) {
      error_log("Unable to connect to database: ". $e->getMessage() );
      if ( function_exists('trigger_error') )
        trigger_error("PDO connection error '".$connection_string."': ".$e->getMessage(),E_USER_ERROR);
      throw $e;
    }
  }
 
 

  function SetSearchPath( $search_path = null ) {
    if ( !isset($this->dialect) ) {
      trigger_error("Unsupported database dialect",E_USER_ERROR);
    }
 
    switch ( $this->dialect ) {
      case 'pgsql':
        if ( $search_path == null ) $search_path = 'public';
        $sql = "SET search_path TO " . $search_path;
        $sth = $this->db->query($sql);
        return $sql;
    }
  }
 

  function GetVersion( ) {
    if ( isset($this->version) ) return $this->version;
    if ( !isset($this->dialect) ) {
      trigger_error("Unsupported database dialect", E_USER_ERROR);
    }
 
    $version = $this->dialect.':';
 
    switch ( $this->dialect ) {
      case 'pgsql':
        $sql = "SELECT version()";
        if ( $sth = $this->db->query($sql) ) {
          $row = $sth->fetch(PDO::FETCH_NUM);
          $version .= preg_replace( '/^PostgreSQL (\d+\.\d+)\..*$/i', '$1', $row[0]);
        }
        break;
      default:
        return null;
    }
    $this->version = $version;
    return $version;
  }
 

  function GetFields( $tablename_string ) {
    if ( !isset($this->dialect) ) {
      trigger_error("Unsupported database dialect", E_USER_ERROR);
    }
 
    switch ( $this->dialect ) {
      case 'pgsql':
        $schema = null;
        $table = null;
        if ( strpos($tablename_string, '.') ) {
          list( $schema, $table ) = explode('.', $tablename_string, 2);
        } else {
          $table = $tablename_string;
        }
 
        $sql = 'SELECT f.attname AS fieldname, t.typname AS typename, f.atttypmod AS precision FROM pg_attribute f';
        $sql .= ' JOIN pg_class c ON ( f.attrelid = c.oid )';
        $sql .= ' JOIN pg_type t ON ( f.atttypid = t.oid )';
        $sql .= ' JOIN pg_namespace ns ON ( c.relnamespace = ns.oid )';
        $sql .= ' WHERE relname = '.$this->Quote($table,PDO::PARAM_STR).' AND attnum >= 0 ';
        if ( isset($schema) ) $sql .= ' AND ns.nspname = '.$this->Quote($schema,PDO::PARAM_STR);
        $sql .= ' ORDER BY f.attnum';
        dbg_error_log('AwlDBDialect', $sql);
        return $sql;
    }
  }
 

  function TranslateSQL( $sql_string ) {
    // Noop for the time being...
    return $sql_string;
  }
 
 

  function Quote( $value, $value_type = null ) {
    if ( isset($value_type) && $value_type == 'identifier' ) {
      if ( $this->dialect == 'mysql' ) {
        $rv = '`' . str_replace('`', '\\`', $value ) . '`';
      }
      else {
        $rv = '"' . str_replace('"', '\\"', $value ) . '"';
      }
      return $rv;
    }
 
    if ( !isset($value_type) ) {
      if ( !isset($value) )       $value_type = PDO::PARAM_NULL;
      elseif ( is_bool($value) )  $value_type = PDO::PARAM_BOOL;
      elseif ( is_float($value) ) $value_type = PDO::PARAM_INT;
      elseif ( is_numeric($value)) {
        if ( preg_match('{^(19|20)\d\d(0[1-9]|1[012])([012]\d|30|31)$}', $value) )
          $value_type = PDO::PARAM_STR; // YYYYMMDD
        elseif ( preg_match('{^0x}i', $value) )
          $value_type = PDO::PARAM_STR; // Any hex numbers will need to be explicitly cast in SQL
        elseif ( preg_match('{^[0-9+-]+e[0-9+-]+$}i', $value) )
          $value_type = PDO::PARAM_STR; // 72e57650 could easily be a string and will need an explicit cast also
        elseif ( preg_match('/^[01]{6,}$/i', $value) )
          $value_type = PDO::PARAM_STR; // Binary numbers will need to be explicitly cast in SQL
        else
          $value_type = PDO::PARAM_INT;
      }
      else
        $value_type = PDO::PARAM_STR;
    }
 
    if ( is_string($value_type) ) {
      switch( $value_type ) {
        case 'null':
          $value_type = PDO::PARAM_NULL;
          break;
        case 'integer':
        case 'double' :
          $value_type = PDO::PARAM_INT;
          break;
        case 'boolean':
          $value_type = PDO::PARAM_BOOL;
          break;
        case 'string':
          $value_type = PDO::PARAM_STR;
          break;
      }
    }
 
    switch ( $value_type ) {
      case PDO::PARAM_NULL:
        $rv = 'NULL';
        break;
      case PDO::PARAM_INT:
        $rv = $value;
        break;
      case PDO::PARAM_BOOL:
        $rv = ($value ? 'TRUE' : 'FALSE');
        break;
      case PDO::PARAM_STR:
      default:
        $rv = "'".str_replace("'", "''", str_replace(':', '\\x3a', str_replace('\\', '\\x5c', $value)))."'";
 
        if ( $this->dialect == 'pgsql' && strpos( $rv, '\\' ) !== false ) {
          $rv = 'E'.str_replace('?', '\\x3f', $rv);
        }
 
    }
 
    return $rv;
 
  }
 

  function ReplaceParameters() {
    $argc = func_num_args();
    $args = func_get_args();
 
    if ( is_array($args[0]) ) {
      $args = $args[0];
      $argc = count($args);
    }
    $qry = array_shift($args);
 
    if ( is_array($args[0]) ) {
      $args = $args[0];
      $argc = count($args);
    }
 
    if ( ! isset($args[0]) ) return $this->ReplaceNamedParameters($qry,$args);

    $parts = explode( '?', $qry, $argc + 1 );
    $querystring = $parts[0];
    $z = count($parts);
 
    for( $i = 0; $i < $argc; $i++ ) {
      $arg = $args[$i];
      $querystring .= $this->Quote($arg);  //parameter
      $z = $i+1;
      if ( isset($parts[$z]) ) $querystring .= $parts[$z];
    }
 
    return $querystring;
  }

  function ReplaceNamedParameters() {
    $argc = func_num_args();
    $args = func_get_args();
 
    if ( is_array($args[0]) ) {
      $args = $args[0];
      $argc = count($args);
    }
    $querystring = array_shift($args);
 
    if ( is_array($args[0]) ) {
      $args = $args[0];
      $argc = count($args);
    }
 
    foreach( $args AS $name => $value ) {
      if ( substr($name, 0, 1) != ':' ) {
        dbg_error_log( "ERROR", "AwlDBDialect: Named parameter '%s' does not begin with a colon.", $name);
      }
      $replacement = str_replace('$', '\\$', $this->Quote($value));  // No positional replacement in $replacement!
      $querystring = preg_replace( '{\Q'.$name.'\E\b}s', $replacement, $querystring );
    }
 
    return $querystring;
  }
 
}