path: root/db_record.class

<?php
/*
**	$Id$
**
**	it_db_record.class - A database record based on it_db_table and it_db
**
**	ITools - the Internet Tools Library
**
**	Copyright (C) 1995-2003 by the ITools Authors.
**	This program is free software; you can redistribute it and/or
**	modify it under the terms of either the GNU General Public License
**	or the GNU Lesser General Public License, as published by the Free
**	Software Foundation. See http://www.gnu.org/licenses/ for details.
*/

/**
 * Functions to handle MySQL records
 * @see it_db, it_db_table
 */
class it_db_record
{
	var $table;		/* Table object */
	var $handle;		/* SQL handle for select() / fetch_next() */
	var $keyfieldname;	/* Name of primary key field */
	var $key;		/* Key of loaded record or empty if no record is loaded */
	var $data = array();	/* Data fields */


/**
 * Initialize internal data (table object and name of key field)
 * @param $table Underlying table object (class it_db_table)
 * @param $keyfieldname Optional name of primary key field, defaults to 'ID'
 */
function it_db_record(&$table, $keyfieldname='ID')
{
	$this->table = &$table;
	$this->keyfieldname = $keyfieldname;
}


/**
 * Change active key field
 * @param $keyfieldname Optional name of primary key field, defaults to 'ID'
 */
function set_key_field($keyfieldname='ID')
{
	$this->keyfieldname = $keyfieldname;
	$this->key = isset($this->data[$keyfieldname]) ? $this->data[$keyfieldname] : '';
}


/**
 * Select a set of records of this table according to an array of selection
 * and sorting criteria.
 * Use fetch_next() to iterate through the result set<br>
 * Example:<br>
 * $record->select(array('Type' => 'bar', 'Date >=' => '1999-01-01',
 *    '-Date <' => 'NOW()', 'User NI' => 'chris'), 'ORDER BY Date');
 *
 * @param $params optional array of fieldname => value tupels.
 * These are ANDed to form a WHERE clause.
 * fieldname can contain an operator (separated by space), the
 * default operator is '='. The special operator 'NI' specifies
 * that the argument must be contained in a comma-separated list.
 *
 * @param $sql Optional SQL addendum added after $params (ORDER BY etc.)
 * @param $fields Optional field list to select (defaults to '*')
 * @return Number of rows that matched this query
 * @see it_db_record::fetch_next, it_db_table::construct_sql_clause
 *
 */
function select($params='', $sql='', $fields='*')
{
	$this->handle = $this->table->safe_sql_select($this->table->construct_sql_clause($params, $sql), $fields);
	return $this->table->db->num_rows($this->handle);
}


/**
 * Post-process data after reading a record.
 * This is a stub-function that can be overloaded.
 */
function _read_post_process()
{
}


/**
 * Pre-process data before writing a record.
 * This is a stub-function that can be overloaded.
 * @param $tags Reference to update/create tags, can be modified as needed
 */
function _write_pre_process(&$tags)
{
}


/**
 * Fetch the next record of a select() query
 * @return true if a record was successfully fetched, false otherwise
 * @see it_db_record::select
 */
function fetch_next()
{
	return $this->fetch($this->handle);
}


/**
 * Fetch the next record from an SQL result into this object.
 * If no more records are pending, clear the object's data.
 * @param $sqlresult Result of table::sql_select() or similar
 * @return 1 if a record was successfully fetched, 0 otherwise
 */
function fetch(&$sqlresult)
{
	$result = 0;

	if ($this->data = $this->table->db->fetch_assoc($sqlresult))
	{
		$this->key = $this->data[$this->keyfieldname];
		$result = 1;
	}
	else
	{
		$this->key = "";	/* "No record is loaded" */
		$this->data = array();	/* Clear local record data */
	}

	$this->_read_post_process();

	return  $result;
}


/**
 * Read a record from table
 * @param $key key field value of the desired row
 * @return 1 on success, 0 otherwise
 */
function read($key)
{
	$result = 0;

	if ($key != "")
	{
		$result = $this->fetch($this->table->safe_sql_select("WHERE $this->keyfieldname='" . mysql_real_escape_string($key) . "'"));
	}
	else
	{
		$this->key = "";	/* "No record is loaded" */
		$this->data = array();	/* Clear local record data */
	}

	$this->_read_post_process();

	return $result;
}


/**
 * Create a new record in the table
 * @see it_db_record::record_create, it_db_record::safe_create
 * @param $tags array of Fieldname/Value pairs
 * @param $replace use REPLACE (1) instead of INSERT (otherwise)
 * @return MySQL result (0 means failure)
 */
function create($tags, $replace=0)
{
	/* Pre-processing, $tags is passed by reference and may be modified here */
	$this->_write_pre_process($tags);

	$sql = $replace ? "REPLACE" : "INSERT";
	$sql .= " INTO " . $this->table->name . " (";
	$sql2 = '';

	unset($this->data);
	for ($sep=""; $ti = each($tags); $sep=",")
	{
		/* If the field name starts with '-', the value is taken as raw, no escaping
		   is done and no quotes are put around it. */
		if (substr($ti[0], 0, 1) == '-')
		{
			$ti[0] = substr($ti[0], 1);	/* Strip that '-' sign */
			$val = $ti[1];
		}
		else
			$val = isset($ti[1]) ? "'".mysql_real_escape_string($ti[1])."'" : 'NULL';

		$this->data[$ti[0]] = $ti[1];	/* Store data for later use */

		$sql .= $sep . $ti[0];
		$sql2 .= "$sep$val";
	}

	$sql .= ") VALUES ($sql2)";

	if ($result = $this->table->db->sql_query($sql))
	{
		/* If the key element was not given, it means it's an AUTO_INCREMENT thingy. */
		if (($this->key = $this->data[$this->keyfieldname]) == "")
		{
			$result = $this->table->db->safe_sql_query("SELECT LAST_INSERT_ID()");
			$this->key = mysql_result($result, 0, 0);
		}

		/* We need all fields from record, not only those we initialised */
		$this->read($this->key);
	}

	return $result;
}


/**
 * Safe version of create (doesn't return in case of failure)
 * @see it_db_record::create, it_db_record::record_create
 * @param $tags array of Fieldname/Value pairs
 * @param $replace use REPLACE (1) instead of INSERT (otherwise)
 * @return MySQL result (0 means failure)
 */
function safe_create($tags, $replace=0)
{
	if ($result = $this->create($tags, $replace))
		return $result;
	else
		fail("it_db_record::safe_create() failed: " . $this->table->db->error());
}


/**
 * Update a record in the table
 * @param $tags array of Fieldname/Value pairs
 * @return MySQL result (0 means failure)
 */
function update($tags)
{
	/* Pre-processing, $tags is passed by reference and may be modified here */
	$this->_write_pre_process($tags);

	if ($this->key == "")
		it::fatal("it_db_record::update(): can't update undefined record");

	/* If we have nothing to do, return instead of performing an invalid SQL query */
	if (!count($tags))
		return true;

	$sql = "UPDATE " . $this->table->name . " SET ";

	for ($sep="", $raw=0; $ti = each($tags); $sep=",")
	{
		/* If the field name starts with '-', the value is taken as raw, no escaping
		   is done and no quotes are put around it. */
		if (substr($ti[0], 0, 1) == '-')
		{
			$ti[0] = substr($ti[0], 1);	/* Strip that '-' sign */
			$val = $ti[1];
			$raw++;
		}
		else
			$val = "'".mysql_real_escape_string($ti[1])."'";

		$sql .= $sep.$ti[0].'='.$val;

		if ($ti[0] == $this->key)
		{
			if ($this->data[$this->keyfieldname] != $ti[0])
				it::fatal("$sql: trying to change key from $this->key.");
		}

		$this->data[$ti[0]] = $ti[1];
	}

	$sql .= " WHERE " . $this->keyfieldname . "='" . mysql_real_escape_string($this->key) . "'";

	/* debug("it_db_record::update(): $sql"); */
	$ret = $this->table->db->safe_sql_query($sql);

	/* Only re-read record if necessary (for performance), but always do post-processing. */
	if ($raw)
		$this->read($this->key);
	else
		$this->_read_post_process();

	return $ret;
}


/**
 * Delete the current record from the database
 * @param $key keyfield value of the record to be deleted. If this is missing, the current record is deleted. 
 * @return MySQL result (0 means failure)
 */
function delete($key="")
{
	if (!$key) $key = $this->key;

	if (($this->table->name == "") || ($this->keyfieldname == "") || ($key == ""))
		it::fatal("it_db_record::delete(): no record\n");

	$sql = "DELETE FROM " . $this->table->name . " WHERE ". $this->keyfieldname . "='" . mysql_real_escape_string($key) . "'";
	if ($result = $this->table->db->sql_query($sql))
	{
		$this->key = "";
		$this->data = array();
	}
	return $result;
}


/**
 * Return a field of a record.
 * @param $field field name
 * @return field value. If the field does not exists, issue an
 * error message and terminate program execution.
 */
function safe_get_field($field)
{
	if ($field)
	{
		if (isset($this->data[$field]))
			return $this->data[$field];
		else it::fatal("it_db_record::safe_get_field(): field \"$field\" not present in record.");
	}
	else it::fatal("it_db_record::safe_get_field(): empty field name");
}


/**
 * Output all fields of a record in (ugly) html format
 */
function dump_html()
{
	echo "<br>Dump of table " . $this->table->name . ", record " . $this->keyfieldname . " = \"" . $this->key . "\":<br><pre>\n";
	reset($this->data); next($this->data);
	while(list($key, $value) = each($this->data))
	{
		if ($key > 0) continue;	/* $$$ ugly */
		echo $key . " = \"" . htmlspecialchars($value) . "\"\n";
	}
	echo "</pre><br>\n";
}


/**
 * Edit a record of a table. Create a new record if necessary.<br>
 * Example:<br>
 * $record->edit($id, array('ID' => $id));
 *
 * @param $key key value of the row to edit
 * @param $fixfields Array of fields not editable (with fixed values)
 * @return 1=changed, 2=created, -1=deleted, 0=nothing changed
 */
function edit($key, $fixfields = array())
{
	$returnresult = 0;
	$numfields = $this->table->num_fields();

	if ($_REQUEST['_COMMAND'])
	{
		/*
		**  If the key field is changed, $key will carry a wrong value, so we
		**  take the correct one from $_RECORD_KEY_VALUE
		*/
		$key = $_REQUEST['_RECORD_KEY_VALUE'];

		switch($_REQUEST['_COMMAND'])
		{
		case "EDIT":
			$this->read($key);
			$newdata = array();
			$changes = 0;
			for ($i=0; $i < $numfields; ++$i)
			{
				$fieldname = $this->table->fieldnames[$i];

				/* Assumes field order is fixed */
				if (isset($fixfields[$fieldname]))
					$newvalue = $fixfields[$fieldname];
				else if (is_array($_REQUEST["_RECORD_$fieldname"]))
					$newvalue = join(',', $_REQUEST["_RECORD_$fieldname"]);
				else
					$newvalue = $_REQUEST["_RECORD_$fieldname"];
	
				if ($this->data[$fieldname] != $newvalue)
				{
					$newdata[$fieldname] = $newvalue;
					$changes = 1;
				}
			}

			if ($changes)
			{
				if ($this->update($newdata))
				{
					echo "<b>Änderung erfolgreich durchgef&uuml;hrt.</b><br>\n";
					$returnresult = 1;
				}
				else
					fail("Update failed.");
			}
			else echo "<b>Keine Änderungen.</b><br>\n";
			break;

		case "CREATE":
			$newdata = array();
			for ($i=0; $i < $numfields; ++$i)
			{
				$fieldname = $this->table->fieldnames[$i];
				
				if (isset($fixfields[$fieldname]))
					$newvalue = $fixfields[$fieldname];
				else if (is_array($_REQUEST["_RECORD_$fieldname"]))
					$newvalue = join(',', $_REQUEST["_RECORD_$fieldname"]);
				else
					$newvalue = $_REQUEST["_RECORD_$fieldname"];

				$newdata[$fieldname] = $newvalue;
			}

			if ($this->create($newdata))
			{
				$key = $this->key;
				echo "<b>Datensatz erzeugt.</b><br>\n";
				$returnresult = 2;
			}
			else
				fail("Datensatz konnte nicht erzeugt werden.");
			break;

		case "DELETE":
			if ($this->delete($key))
			{
				echo "<b>Datensatz gelöscht.</b><br>\n";
				$returnresult = -1;
			}
			else
				fail("Datensatz konnte nicht gelöscht werden.");
			break;

		default:
			fail("Unknown _COMMAND \"{$_REQUEST['_COMMAND']}\"");
			/* NOT REACHED */
		}
	}

	if ($key != "")
	{
		$this->read($key);
		$cmd = "EDIT";
		$buttontext = "Änderungen übernehmen";
	}
	else
	{
		$cmd = "CREATE";
		$buttontext = "Datensatz erzeugen";
	}

	echo "<form action=\"\" method=\"post\"><input type=\"hidden\" name=\"_COMMAND\" value=\"$cmd\"><input type=\"hidden\" name=\"_RECORD_KEY_NAME\" value=\"$this->keyfieldname\"><input type=\"hidden\" name=\"_RECORD_KEY_VALUE\" value=\"$this->key\">\n";
	echo "<table border=1 cellspacing=0 cellpadding=4>\n";
	for ($i=0; $i < $numfields; ++$i)
	{
		$fieldname = $this->table->fieldnames[$i];

		/* Do not display fix fields */
		if (isset($fixfields[$fieldname]))
			continue;

		$fieldflags = $this->table->fieldflags[$i];
		$fieldlen  = $this->table->fieldlengths[$i];
		$size = min($fieldlen, 65);

		if ($fieldname == $this->keyfieldname)
			echo "<tr><th align=right>$fieldname</th>";
		else
			echo "<tr><td align=right>$fieldname</td>";

		if (strstr($fieldflags, "blob"))
		{
			if (strlen($this->data["$fieldname"]) < 256)
				echo "<td><textarea name=\"_RECORD_$fieldname\" rows=4 cols=56 wrap=\"physical\">" . htmlspecialchars($this->data["$fieldname"]) . "</textarea></td></tr>\n";
			else
				echo "<td><textarea name=\"_RECORD_$fieldname\" rows=10 cols=75 wrap=\"physical\">" . htmlspecialchars($this->data["$fieldname"]) . "</textarea></td></tr>\n";
		}
		else if (strstr($fieldflags, "enum"))
		{
			$result = $this->table->db->safe_sql_query("SHOW columns FROM ". $this->table->name . " LIKE '$fieldname'");
			$options = split("'", mysql_result($result, 0, 1));

			$vals = explode(',', $this->data[$fieldname]);

			for ($j = 0; $j < count($vals); $j++)
				$values[$vals[$j]] = 1;

			if (strstr($options[0], 'set'))
				$attr = 'multiple';
			else
				$attr = 'set="1"';

			echo "<td><select name=\"_RECORD_${fieldname}[]\" $attr>";
			for ($j=1; $options[$j]; $j+=2)
			{
				$selected = $values[$options[$j]] ? " selected" : "";
				echo "<option$selected>", $options[$j], "</option>";
			}
			echo "</select></td></tr>\n";
		}
		else
			echo "<td><input type=\"text\" size=$size name=\"_RECORD_$fieldname\" maxlength=\"$fieldlen\" value=\"" . htmlspecialchars($this->data["$fieldname"]) . "\"></td></tr>\n";
	}
	echo "</table><br><input type=\"submit\" value=\"$buttontext\"></form>\n";

	if ($this->key != "")
		echo "<form action=\"\" method=\"post\"><input type=\"hidden\" name=\"_COMMAND\" value=\"DELETE\"><input type=\"hidden\" name=\"_RECORD_KEY_NAME\" value=\"$this->keyfieldname\"><input type=\"hidden\" name=\"_RECORD_KEY_VALUE\" value=\"$this->key\"><input type=\"submit\" value=\"Datensatz löschen\"></form>\n";

	return $returnresult;
}

} /* End class it_db_record */
?>