Moved itools to live branch

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+<?php
+/*
+**	$Id$
+**
+**	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.
+**
+**	it_db.class - Generic Database class, currently using mysql.
+**
+**	This tries to be as efficient as possible by maintaining
+**	persistent database connections.
+*/
+
+
+/**
+ * Functions to handle SQL databases
+ * @see it_db_table, it_db_record
+ */
+class it_db
+{
+	/* public */
+	var	$host;			/* Database host */
+	var	$host_update='';	/* Optional database host for updates */
+	var	$name;			/* Name of database */
+	var	$numtables;		/* Number of tables in databasee or 0 if not known */
+	var	$tablenames = array();	/* Array(0..$numtables) of table names */
+
+	/* private */
+	var	$link;			/* MySQL Link Identifier */
+	var	$username;		/* MySQL username (if $updatehost) */
+	var	$password;		/* MySQL password (if $updatehost) */
+
+/**
+ * Constructor: connect to MySQL server and select database
+ * @param $databasename name of the database to select or empty for default
+ * @param $username username to connect with
+ * @param $password password to connect with
+ * @param $host Optional name of the host to connect to
+ * @param $host_update Optional name of the host for updates (writes)
+ */
+function it_db($databasename, $username, $password, $host='localhost', $host_update='')
+{
+	if (empty($databasename))
+		$databasename = strtr(ereg_replace('^www.', '', strtolower(ereg_replace(':.*$', '', getenv('HTTP_HOST')))), '.', '_');
+
+	if ($this->link = @mysql_connect($host, $username, $password, true))
+	{
+		if (mysql_select_db($databasename, $this->link))
+		{
+			$this->host = $host;
+			$this->name = $databasename;
+		}
+		else
+			internal_error("Can't select database \"$databasename\" on host \"$host\".");
+	}
+	else
+		internal_error("Can't connect to database server \"$host\" as user \"$username\".");
+
+	if ($host_update)
+	{
+		$this->host_update = $host_update;
+		$this->username = $username;
+		$this->password = $password;
+	}
+}
+
+
+/**
+ * Perform an SQL query.
+ * @see ::safe_sql_query, mysql_query
+ * @param $sql SQL query
+ * @return SQL handle or false in case of failure
+ */
+function sql_query($sql)
+{
+	debug("it_db::sql_query($sql) on {$this->host}", 5);
+
+	/*
+	** If we have a special update host, and an update operation is to be
+	** performed, we switch to this host. And we stay forever and ever and ever...
+	*/
+	if ($this->host_update && eregi('^(UPDATE|INSERT|REPLACE|DELETE|ALTER) ', $sql))
+	{
+		/*debug('it_db::sql_query(): switching to update host "'.$this->host_update.'"', 3); */
+		if ($this->link = @mysql_connect($this->host_update, $this->username, $this->password, true))
+		{
+			if (mysql_select_db($this->name, $this->link))
+				$this->host = $this->host_update;
+			else
+				internal_error('Error selecting update database "'.$this->name.'" on host "'.$this->host_update.'".');
+
+			$this->host_update='';
+		}
+		else
+			internal_error('Error connecting to update database server "'.$this->host_update.'" as user "'.$this->username.'".');
+	}
+	
+	return mysql_query($sql, $this->link);
+}
+
+
+/**
+ * Perform an SQL query. If the query fails, issue an error message
+ * and terminate program execution. No matching rows does not mean failure.
+ * @see ::sql_query, mysql_query
+ * @param $sql SQL query
+ * @return SQL handle
+ */
+function safe_sql_query($sql)
+{
+	/* debug("it_db::safe_sql_query($sql)", 4); */
+	if ($result = $this->sql_query($sql))
+		return $result;
+	else
+	{
+		if ($this->errno() == 1062)	/* Duplicate entry */
+			return 0;
+
+		fail('SQL-Query db "'.$this->name.'" host "'.$this->host."\" failed: \"$sql\":<br>".$this->error().' ('.$this->errno().')');
+	}
+}
+
+
+/**
+ * Free resources used by SQL handle
+ * @see mysql_free_result
+ * @param $handle SQL handle
+ * @return 
+ */
+function free($handle)
+{
+	return mysql_free_result($handle);
+}
+
+
+/**
+ * Fetch a row as an array
+ * @see mysql_fetch_array
+ * @param $handle SQL handle
+ * @return numeric & associative array with contents of table row
+ */
+function fetch_array($handle)
+{
+	return mysql_fetch_array($handle);
+}
+
+
+/**
+ * Fetch a row as an associative array
+ * @see mysql_fetch_array
+ * @param $handle SQL handle
+ * @return associative array with contents of table row
+ */
+function fetch_assoc($handle)
+{
+	return mysql_fetch_assoc($handle);
+}
+
+
+/**
+ * Return number of rows of a query
+ * @see mysql_num_rows
+ * @param $handle SQL handle
+ * @return number of rows the query returned
+ */
+function num_rows($handle)
+{
+	return mysql_num_rows($handle);
+}
+
+
+/**
+ * Return number of found rows of a limited query that had SQL_COUNT_FOUND_ROWS set
+ * @return number of rows the query would have returned without LIMIT
+ */
+function found_rows()
+{
+	list($count) = mysql_fetch_row($this->safe_sql_query('SELECT FOUND_ROWS()'));
+	return intval($count);
+}
+
+
+/* Internal: get information about tables */
+function _get_table_info()
+{
+	if ($this->numtables > 0) /* Already done! */
+		return;
+
+	if(($tables = mysql_list_tables($this->name,$this->link)) >= 0)
+	{
+		$this->numtables = mysql_numrows($tables);
+		for ($i=0; $i < $this->numtables; ++$i)
+		{
+			$name = mysql_tablename($tables, $i);
+			$this->tablenames[$i] = $name;
+		}
+	}
+	else internal_error("mysql_list_tables($this->name,$this->link) failed.");
+}
+
+
+/**
+ * Return a list of all table names of this database
+ * @return array with tablenames of this Database
+ */
+function table_names()
+{
+	$this->_get_table_info();
+	return $this->tablenames;
+}
+
+
+/**
+ * Return number of tables in this database
+ */
+function num_tables()
+{
+	$this->_get_table_info();
+	return $this->numtables;
+}
+
+
+/**
+ * Return last error number
+ * @see ::sql_query, ::safe_sql_query, mysql_errno
+ * @return last mySQL error number
+ */
+function errno()
+{
+	return mysql_errno($this->link);
+}
+
+
+/**
+ * Return last error string
+ * @see ::sql_query, ::safe_sql_query, mysql_error
+ * @return last mySQL error message
+ */
+function error()
+{
+	return mysql_error($this->link);
+}
+
+} /* End class it_db */
+?>