php教程:mysql数据库操作的DB类

代码拷贝框

/*
*mysql数据库 DB类
*@packagedb
*@authoryytcpt(无影)
*@version2008-03-27
*@copyrigthhttp://www.d5s.cn/
*/
class db {
var $connection_id = "";
var $pconnect = 0;
var $shutdown_queries = array();
var $queries = array();
var $query_id = "";
var $query_count = 0;
var $record_row = array();
var $failed = 0;
var $halt = "";
var $query_log = array();
function connect($db_config){
if ($this->pconnect){
$this->connection_id = mysql_pconnect($db_config["hostname"], $db_config["username"], $db_config["password"]);
}else{
$this->connection_id = mysql_connect($db_config["hostname"], $db_config["username"], $db_config["password"]);
}
if ( ! $this->connection_id ){
$this->halt("Can not connect MySQL Server");
}
if ( ! @mysql_select_db($db_config["database"], $this->connection_id) ){
$this->halt("Can not connect MySQL Database");
}
if ($db_config["charset"]) {
@mysql_unbuffered_query("SET NAMES '".$db_config["charset"]."'");
}
return true;
}
//发送SQL 查询，并返回结果集
function query($query_id, $query_type='mysql_query'){
$this->query_id = $query_type($query_id, $this->connection_id);
$this->queries[] = $query_id;
if (! $this->query_id ) {
$this->halt("查询失败:\n$query_id");
}
$this->query_count++;
$this->query_log[] = $str;
return $this->query_id;
}
//发送SQL 查询，并不获取和缓存结果的行
function query_unbuffered($sql=""){
return $this->query($sql, 'mysql_unbuffered_query');
}
//从结果集中取得一行作为关联数组
function fetch_array($sql = ""){
if ($sql == "") $sql = $this->query_id;
$this->record_row = @mysql_fetch_array($sql, MYSQL_ASSOC);
return $this->record_row;
}
function shutdown_query($query_id = ""){
$this->shutdown_queries[] = $query_id;
}
//取得结果集中行的数目，仅对 INSERT，UPDATE 或者 DELETE
function affected_rows() {
return @mysql_affected_rows($this->connection_id);
}
//取得结果集中行的数目，仅对 SELECT 语句有效
function num_rows($query_id="") {
if ($query_id == "") $query_id = $this->query_id;
return @mysql_num_rows($query_id);
}
//返回上一个 MySQL 操作中的错误信息的数字编码
function get_errno(){
$this->errno = @mysql_errno($this->connection_id);
return $this->errno;
}
//取得上一步 INSERT 操作产生的 ID
function insert_id(){
return @mysql_insert_id($this->connection_id);
}
//得到查询次数
function query_count() {
return $this->query_count;
}
//释放结果内存
function free_result($query_id=""){
if ($query_id == "") $query_id = $this->query_id;
@mysql_free_result($query_id);
}
//关闭 MySQL 连接
function close_db(){
if ( $this->connection_id ) return @mysql_close( $this->connection_id );
}
//列出 MySQL 数据库中的表
function get_table_names(){
global $db_config;
$result = mysql_list_tables($db_config["database"]);
$num_tables = @mysql_numrows($result);
for ($i = 0; $i < $num_tables; $i++) {
$tables[] = mysql_tablename($result, $i);
}
mysql_free_result($result);
return $tables;
}
//从结果集中取得列信息并作为对象返回，取得所有字段
function get_result_fields($query_id=""){
if ($query_id == "") $query_id = $this->query_id;
while ($field = mysql_fetch_field($query_id)) {
$fields[] = $field;
}
return $fields;
}
//错误提示
function halt($the_error=""){
$message = $the_error."
\r\n";
$message.= $this->get_errno() . "
\r\n";
$sql = "INSERT INTO `db_error`(pagename, errstr, timer) VALUES('".$_SERVER["PHP_SELF"]."', '".addslashes($message)."', ".time().")";
@mysql_unbuffered_query($sql);
if (DEBUG==true){
echo "";
echo "\r\n";
echo "\r\n";
echo "

\r\n";
echo "" . htmlspecialchars($message) . "\r\n";
echo "

\r\n";
exit;
}
}
function __destruct(){
$this->shutdown_queries = array();
$this->close_db();
}
function sql_select($tbname, $where="", $limit=0, $fields="*", $orderby="id", $sort="DESC"){
$sql = "SELECT ".$fields." FROM `".$tbname."` ".($where?" WHERE ".$where:"")." ORDER BY ".$orderby." ".$sort.($limit ? " limit ".$limit:"");
return $sql;
}
function sql_insert($tbname, $row){
foreach ($row as $key=>$value) {
$sqlfield .= $key.",";
$sqlvalue .= "'".$value."',";
}
return "INSERT INTO `".$tbname."`(".substr($sqlfield, 0, -1).") VALUES (".substr($sqlvalue, 0, -1).")";
}
function sql_update($tbname, $row, $where){
foreach ($row as $key=>$value) {
$sqlud .= $key."= '".$value."',";
}
return "UPDATE `".$tbname."` SET ".substr($sqlud, 0, -1)." WHERE ".$where;
}
function sql_delete($tbname, $where){
return "DELETE FROM `".$tbname."` WHERE ".$where;
}
//新增加一条记录
function row_insert($tbname, $row){
$sql = $this->sql_insert($tbname, $row);
return $this->query_unbuffered($sql);
}
//更新指定记录
function row_update($tbname, $row, $where){
$sql = $this->sql_update($tbname, $row, $where);
return $this->query_unbuffered($sql);
}
//删除满足条件的记录
function row_delete($tbname, $where){
$sql = $this->sql_delete($tbname, $where);
return $this->query_unbuffered($sql);
}
/*根据条件查询，返回所有记录
*$tbname 表名, $where 查询条件, $limit 返回记录, $fields 返回字段
*/
function row_select($tbname, $where="", $limit=0, $fields="*", $orderby="id", $sort="DESC"){
$sql = $this->sql_select($tbname, $where, $limit, $fields, $orderby, $sort);
return $this->row_query($sql);
}
//详细显示一条记录
function row_select_one($tbname, $where, $fields="*", $orderby="id"){
$sql = $this->sql_select($tbname, $where, 1, $fields, $orderby);
return $this->row_query_one($sql);
}
function row_query($sql){
$rs = $this->query($sql);
$rs_num = $this->num_rows($rs);
$rows = array();
for($i=0; $i<$rs_num; $i++){
$rows[] = $this->fetch_array($rs);
}
$this->free_result($rs);
return $rows;
}
function row_query_one($sql){
$rs = $this->query($sql);
$row = $this->fetch_array($rs);
$this->free_result($rs);
return $row;
}
//计数统计
function row_count($tbname, $where=""){
$sql = "SELECT count(id) as row_sum FROM `".$tbname."` ".($where?" WHERE ".$where:"");
$row = $this->row_query_one($sql);
return $row["row_sum"];
}
}
?>

很久没有发帖了，把我常用的一些php类文件分享出来。
如果您加了新功能，或者是有改进，请与大家一起分享。

$db_config["hostname"] = "127.0.0.1"; //服务器地址
$db_config["username"] = "root"; //数据库用户名
$db_config["password"] = "root"; //数据库密码
$db_config["database"] = "wap_blueidea_com"; //数据库名称
$db_config["charset"] = "utf8";
include('db.php');
$db = new db();
$db->connect($db_config);
//例：查询表 table_name 中 cid=1的所有记录。
$row = $db->row_select('table_name', 'cid=1');
?>

更详细的使用方法，请参考 db类文件中的注释。