今天来点基础的设计模式：
如何利用单例模式实现一个数据库中间层
class Db{
static private $_instance; //当前数据库连接实例
static public function getInstance($config){
if(!isset(self::$_instance)){
//new 创建实例
$class = "Think\\DB\\Driver\\".$config['type'];
self::$_instance = new $class($config);
}
return self::$_instance;
}
}
// +----------------------------------------------------------------------
namespace Think\Db;
use Think\Config;
use Think\Debug;
use Think\Log;
use PDO;
abstract class Driver {
// PDO操作实例
protected $PDOStatement = null;
// 当前操作所属的模型名
protected $model = '_think_';
// 当前SQL指令
protected $queryStr = '';
protected $modelSql = array();
// 最后插入ID
protected $lastInsID = null;
// 返回或者影响记录数
protected $numRows = 0;
// 事务指令数
protected $transTimes = 0;
// 错误信息
protected $error = '';
// 数据库连接ID 支持多个连接
protected $linkID = array();
// 当前连接ID
protected $_linkID = null;
// 数据库连接参数配置
protected $config = array(
'type' => '', // 数据库类型
'hostname' => '127.0.0.1', // 服务器地址
'database' => '', // 数据库名
'username' => '', // 用户名
'password' => '', // 密码
'hostport' => '', // 端口
'dsn' => '', //
'params' => array(), // 数据库连接参数
'charset' => 'utf8', // 数据库编码默认采用utf8
'prefix' => '', // 数据库表前缀
'debug' => false, // 数据库调试模式
'deploy' => 0, // 数据库部署方式:0 集中式(单一服务器),1 分布式(主从服务器)
'rw_separate' => false, // 数据库读写是否分离 主从式有效
'master_num' => 1, // 读写分离后 主服务器数量
'slave_no' => '', // 指定从服务器序号
'db_like_fields' => '',
);
// 数据库表达式
protected $exp = array('eq'=>'=','neq'=>'<>','gt'=>'>','egt'=>'>=','lt'=>'<','elt'=>'<=','notlike'=>'NOT LIKE','like'=>'LIKE','in'=>'IN','notin'=>'NOT IN','not in'=>'NOT IN','between'=>'BETWEEN','not between'=>'NOT BETWEEN','notbetween'=>'NOT BETWEEN');
// 查询表达式
protected $selectSql = 'SELECT%DISTINCT% %FIELD% FROM %TABLE%%FORCE%%JOIN%%WHERE%%GROUP%%HAVING%%ORDER%%LIMIT% %UNION%%LOCK%%COMMENT%';
// 查询次数
protected $queryTimes = 0;
// 执行次数
protected $executeTimes = 0;
// PDO连接参数
protected $options = array(
PDO::ATTR_CASE => PDO::CASE_LOWER,
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_ORACLE_NULLS => PDO::NULL_NATURAL,
PDO::ATTR_STRINGIFY_FETCHES => false,
);
protected $bind = array(); // 参数绑定
/**
* 架构函数 读取数据库配置信息
* @access public
* @param array $config 数据库配置数组
*/
public function __construct($config=''){
if(!empty($config)) {
$this->config = array_merge($this->config,$config);
if(is_array($this->config['params'])){
$this->options = $this->config['params'] + $this->options;
}
}
}
/**
* 连接数据库方法
* @access public
*/
public function connect($config='',$linkNum=0,$autoConnection=false) {
if ( !isset($this->linkID[$linkNum]) ) {
if(empty($config)) $config = $this->config;
try{
if(empty($config['dsn'])) {
$config['dsn'] = $this->parseDsn($config);
}
if(version_compare(PHP_VERSION,'5.3.6','<=')){
// 禁用模拟预处理语句
$this->options[PDO::ATTR_EMULATE_PREPARES] = false;
}
$this->linkID[$linkNum] = new PDO( $config['dsn'], $config['username'], $config['password'],$this->options);
}catch (\PDOException $e) {
if($autoConnection){
trace($e->getMessage(),'','ERR');
return $this->connect($autoConnection,$linkNum);
}elseif($config['debug']){
E($e->getMessage());
}
}
}
return $this->linkID[$linkNum];
}
/**
* 解析pdo连接的dsn信息
* @access public
* @param array $config 连接信息
* @return string
*/
protected function parseDsn($config){}
/**
* 释放查询结果
* @access public
*/
public function free() {
$this->PDOStatement = null;
}
/**
* 执行查询 返回数据集
* @access public
* @param string $str sql指令
* @param boolean $fetchSql 不执行只是获取SQL
* @return mixed
*/
public function query($str,$fetchSql=false) {
$this->initConnect(false);
if ( !$this->_linkID ) return false;
$this->queryStr = $str;
if(!empty($this->bind)){
$that = $this;
$this->queryStr = strtr($this->queryStr,array_map(function($val) use($that){ return '\''.$that->escapeString($val).'\''; },$this->bind));
}
if($fetchSql){
return $this->queryStr;
}
//释放前次的查询结果
if ( !empty($this->PDOStatement) ) $this->free();
$this->queryTimes++;
N('db_query',1); // 兼容代码
// 调试开始
$this->debug(true);
$this->PDOStatement = $this->_linkID->prepare($str);
if(false === $this->PDOStatement){
$this->error();
return false;
}
foreach ($this->bind as $key => $val) {
if(is_array($val)){
$this->PDOStatement->bindValue($key, $val[0], $val[1]);
}else{
$this->PDOStatement->bindValue($key, $val);
}
}
$this->bind = array();
try{
$result = $this->PDOStatement->execute();
// 调试结束
$this->debug(false);
if ( false === $result ) {
$this->error();
return false;
} else {
return $this->getResult();
}
}catch (\PDOException $e) {
$this->error();
return false;
}
}
/**
* 执行语句
* @access public
* @param string $str sql指令
* @param boolean $fetchSql 不执行只是获取SQL
* @return mixed
*/
public function execute($str,$fetchSql=false) {
$this->initConnect(true);
if ( !$this->_linkID ) return false;
$this->queryStr = $str;
if(!empty($this->bind)){
$that = $this;
$this->queryStr = strtr($this->queryStr,array_map(function($val) use($that){ return '\''.$that->escapeString($val).'\''; },$this->bind));
}
if($fetchSql){
return $this->queryStr;
}
//释放前次的查询结果
if ( !empty($this->PDOStatement) ) $this->free();
$this->executeTimes++;
N('db_write',1); // 兼容代码
// 记录开始执行时间
$this->debug(true);
$this->PDOStatement = $this->_linkID->prepare($str);
if(false === $this->PDOStatement) {
$this->error();
return false;
}
foreach ($this->bind as $key => $val) {
if(is_array($val)){
$this->PDOStatement->bindValue($key, $val[0], $val[1]);
}else{
$this->PDOStatement->bindValue($key, $val);
}
}
$this->bind = array();
try{
$result = $this->PDOStatement->execute();
// 调试结束
$this->debug(false);
if ( false === $result) {
$this->error();
return false;
} else {
$this->numRows = $this->PDOStatement->rowCount();
if(preg_match("/^\s*(INSERT\s+INTO|REPLACE\s+INTO)\s+/i", $str)) {
$this->lastInsID = $this->_linkID->lastInsertId();
}
return $this->numRows;
}
}catch (\PDOException $e) {
$this->error();
return false;
}
}
/**
* 启动事务
* @access public
* @return void
*/
public function startTrans() {
$this->initConnect(true);
if ( !$this->_linkID ) return false;
//数据rollback 支持
if ($this->transTimes == 0) {
$this->_linkID->beginTransaction();
}
$this->transTimes++;
return ;
}
/**
* 用于非自动提交状态下面的查询提交
* @access public
* @return boolean
*/
public function commit() {
if ($this->transTimes > 0) {
$result = $this->_linkID->commit();
$this->transTimes = 0;
if(!$result){
$this->error();
return false;
}
}
return true;
}
/**
* 事务回滚
* @access public
* @return boolean
*/
public function rollback() {
if ($this->transTimes > 0) {
$result = $this->_linkID->rollback();
$this->transTimes = 0;
if(!$result){
$this->error();
return false;
}
}
return true;
}
/**
* 获得所有的查询数据
* @access private
* @return array
*/
private function getResult() {
//返回数据集
$result = $this->PDOStatement->fetchAll(PDO::FETCH_ASSOC);
$this->numRows = count( $result );
return $result;
}
/**
* 获得查询次数
* @access public
* @param boolean $execute 是否包含所有查询
* @return integer
*/
public function getQueryTimes($execute=false){
return $execute?$this->queryTimes+$this->executeTimes:$this->queryTimes;
}
/**
* 获得执行次数
* @access public
* @return integer
*/
public function getExecuteTimes(){
return $this->executeTimes;
}
/**
* 关闭数据库
* @access public
*/
public function close() {
$this->_linkID = null;
}
/**
* 数据库错误信息
* 并显示当前的SQL语句
* @access public
* @return string
*/
public function error() {
if($this->PDOStatement) {
$error = $this->PDOStatement->errorInfo();
$this->error = $error[1].':'.$error[2];
}else{
$this->error = '';
}
if('' != $this->queryStr){
$this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
}
// 记录错误日志
trace($this->error,'','ERR');
if($this->config['debug']) {// 开启数据库调试模式
E($this->error);
}else{
return $this->error;
}
}
/**
* 设置锁机制
* @access protected
* @return string
*/
protected function parseLock($lock=false) {
return $lock? ' FOR UPDATE ' : '';
}
/**
* set分析
* @access protected
* @param array $data
* @return string
*/
protected function parseSet($data) {
foreach ($data as $key=>$val){
if(is_array($val) && 'exp' == $val[0]){
$set[] = $this->parseKey($key).'='.$val[1];
}elseif(is_null($val)){
$set[] = $this->parseKey($key).'=NULL';
}elseif(is_scalar($val)) {// 过滤非标量数据
if(0===strpos($val,':') && in_array($val,array_keys($this->bind)) ){
$set[] = $this->parseKey($key).'='.$this->escapeString($val);
}else{
$name = count($this->bind);
$set[] = $this->parseKey($key).'=:'.$name;
$this->bindParam($name,$val);
}
}
}
return ' SET '.implode(',',$set);
}
/**
* 参数绑定
* @access protected
* @param string $name 绑定参数名
* @param mixed $value 绑定值
* @return void
*/
protected function bindParam($name,$value){
$this->bind[':'.$name] = $value;
}
/**
* 字段名分析
* @access protected
* @param string $key
* @return string
*/
protected function parseKey(&$key) {
return $key;
}
/**
* value分析
* @access protected
* @param mixed $value
* @return string
*/
protected function parseValue($value) {
if(is_string($value)) {
$value = strpos($value,':') === 0 && in_array($value,array_keys($this->bind))? $this->escapeString($value) : '\''.$this->escapeString($value).'\'';
}elseif(isset($value[0]) && is_string($value[0]) && strtolower($value[0]) == 'exp'){
$value = $this->escapeString($value[1]);
}elseif(is_array($value)) {
$value = array_map(array($this, 'parseValue'),$value);
}elseif(is_bool($value)){
$value = $value ? '1' : '0';
}elseif(is_null($value)){
$value = 'null';
}
return $value;
}
/**
* field分析
* @access protected
* @param mixed $fields
* @return string
*/
protected function parseField($fields) {
if(is_string($fields) && '' !== $fields) {
$fields = explode(',',$fields);
}
if(is_array($fields)) {
// 完善数组方式传字段名的支持
// 支持 'field1'=>'field2' 这样的字段别名定义
$array = array();
foreach ($fields as $key=>$field){
if(!is_numeric($key))
$array[] = $this->parseKey($key).' AS '.$this->parseKey($field);
else
$array[] = $this->parseKey($field);
}
$fieldsStr = implode(',', $array);
}else{
$fieldsStr = '*';
}
//TODO 如果是查询全部字段，并且是join的方式，那么就把要查的表加个别名，以免字段被覆盖
return $fieldsStr;
}
/**
* table分析
* @access protected
* @param mixed $table
* @return string
*/
protected function parseTable($tables) {
if(is_array($tables)) {// 支持别名定义
$array = array();
foreach ($tables as $table=>$alias){
if(!is_numeric($table))
$array[] = $this->parseKey($table).' '.$this->parseKey($alias);
else
$array[] = $this->parseKey($alias);
}
$tables = $array;
}elseif(is_string($tables)){
$tables = explode(',',$tables);
array_walk($tables, array(&$this, 'parseKey'));
}
return implode(',',$tables);
}
/**
* where分析
* @access protected
* @param mixed $where
* @return string
*/
protected function parseWhere($where) {
$whereStr = '';
if(is_string($where)) {
// 直接使用字符串条件
$whereStr = $where;
}else{ // 使用数组表达式
$operate = isset($where['_logic'])?strtoupper($where['_logic']):'';
if(in_array($operate,array('AND','OR','XOR'))){
// 定义逻辑运算规则 例如 OR XOR AND NOT
$operate = ' '.$operate.' ';
unset($where['_logic']);
}else{
// 默认进行 AND 运算
$operate = ' AND ';
}
foreach ($where as $key=>$val){
if(is_numeric($key)){
$key = '_complex';
}
if(0===strpos($key,'_')) {
// 解析特殊条件表达式
$whereStr .= $this->parseThinkWhere($key,$val);
}else{
// 查询字段的安全过滤
// if(!preg_match('/^[A-Z_\|\&\-.a-z0-9\(\)\,]+$/',trim($key))){
// E(L('_EXPRESS_ERROR_').':'.$key);
// }
// 多条件支持
$multi = is_array($val) && isset($val['_multi']);
$key = trim($key);
if(strpos($key,'|')) { // 支持 name|title|nickname 方式定义查询字段
$array = explode('|',$key);
$str = array();
foreach ($array as $m=>$k){
$v = $multi?$val[$m]:$val;
$str[] = $this->parseWhereItem($this->parseKey($k),$v);
}
$whereStr .= '( '.implode(' OR ',$str).' )';
}elseif(strpos($key,'&')){
$array = explode('&',$key);
$str = array();
foreach ($array as $m=>$k){
$v = $multi?$val[$m]:$val;
$str[] = '('.$this->parseWhereItem($this->parseKey($k),$v).')';
}
$whereStr .= '( '.implode(' AND ',$str).' )';
}else{
$whereStr .= $this->parseWhereItem($this->parseKey($key),$val);
}
}
$whereStr .= $operate;
}
$whereStr = substr($whereStr,0,-strlen($operate));
}
return empty($whereStr)?'':' WHERE '.$whereStr;
}
// where子单元分析
protected function parseWhereItem($key,$val) {
$whereStr = '';
if(is_array($val)) {
if(is_string($val[0])) {
$exp = strtolower($val[0]);
if(preg_match('/^(eq|neq|gt|egt|lt|elt)$/',$exp)) { // 比较运算
$whereStr .= $key.' '.$this->exp[$exp].' '.$this->parseValue($val[1]);
}elseif(preg_match('/^(notlike|like)$/',$exp)){// 模糊查找
if(is_array($val[1])) {
$likeLogic = isset($val[2])?strtoupper($val[2]):'OR';
if(in_array($likeLogic,array('AND','OR','XOR'))){
$like = array();
foreach ($val[1] as $item){
$like[] = $key.' '.$this->exp[$exp].' '.$this->parseValue($item);
}
$whereStr .= '('.implode(' '.$likeLogic.' ',$like).')';
}
}else{
$whereStr .= $key.' '.$this->exp[$exp].' '.$this->parseValue($val[1]);
}
}elseif('bind' == $exp ){ // 使用表达式
$whereStr .= $key.' = :'.$val[1];
}elseif('exp' == $exp ){ // 使用表达式
$whereStr .= $key.' '.$val[1];
}elseif(preg_match('/^(notin|not in|in)$/',$exp)){ // IN 运算
if(isset($val[2]) && 'exp'==$val[2]) {
$whereStr .= $key.' '.$this->exp[$exp].' '.$val[1];
}else{
if(is_string($val[1])) {
$val[1] = explode(',',$val[1]);
}
$zone = implode(',',$this->parseValue($val[1]));
$whereStr .= $key.' '.$this->exp[$exp].' ('.$zone.')';
}
}elseif(preg_match('/^(notbetween|not between|between)$/',$exp)){ // BETWEEN运算
$data = is_string($val[1])? explode(',',$val[1]):$val[1];
$whereStr .= $key.' '.$this->exp[$exp].' '.$this->parseValue($data[0]).' AND '.$this->parseValue($data[1]);
}else{
E(L('_EXPRESS_ERROR_').':'.$val[0]);
}
}else {
$count = count($val);
$rule = isset($val[$count-1]) ? (is_array($val[$count-1]) ? strtoupper($val[$count-1][0]) : strtoupper($val[$count-1]) ) : '' ;
if(in_array($rule,array('AND','OR','XOR'))) {
$count = $count -1;
}else{
$rule = 'AND';
}
for($i=0;$i<$count;$i++) {
$data = is_array($val[$i])?$val[$i][1]:$val[$i];
if('exp'==strtolower($val[$i][0])) {
$whereStr .= $key.' '.$data.' '.$rule.' ';
}else{
$whereStr .= $this->parseWhereItem($key,$val[$i]).' '.$rule.' ';
}
}
$whereStr = '( '.substr($whereStr,0,-4).' )';
}
}else {
//对字符串类型字段采用模糊匹配
$likeFields = $this->config['db_like_fields'];
if($likeFields && preg_match('/^('.$likeFields.')$/i',$key)) {
$whereStr .= $key.' LIKE '.$this->parseValue('%'.$val.'%');
}else {
$whereStr .= $key.' = '.$this->parseValue($val);
}
}
return $whereStr;
}
/**
* 特殊条件分析
* @access protected
* @param string $key
* @param mixed $val
* @return string
*/
protected function parseThinkWhere($key,$val) {
$whereStr = '';
switch($key) {
case '_string':
// 字符串模式查询条件
$whereStr = $val;
break;
case '_complex':
// 复合查询条件
$whereStr = substr($this->parseWhere($val),6);
break;
case '_query':
// 字符串模式查询条件
parse_str($val,$where);
if(isset($where['_logic'])) {
$op = ' '.strtoupper($where['_logic']).' ';
unset($where['_logic']);
}else{
$op = ' AND ';
}
$array = array();
foreach ($where as $field=>$data)
$array[] = $this->parseKey($field).' = '.$this->parseValue($data);
$whereStr = implode($op,$array);
break;
}
return '( '.$whereStr.' )';
}
/**
* limit分析
* @access protected
* @param mixed $lmit
* @return string
*/
protected function parseLimit($limit) {
return !empty($limit)? ' LIMIT '.$limit.' ':'';
}
/**
* join分析
* @access protected
* @param mixed $join
* @return string
*/
protected function parseJoin($join) {
$joinStr = '';
if(!empty($join)) {
$joinStr = ' '.implode(' ',$join).' ';
}
return $joinStr;
}
/**
* order分析
* @access protected
* @param mixed $order
* @return string
*/
protected function parseOrder($order) {
if(is_array($order)) {
$array = array();
foreach ($order as $key=>$val){
if(is_numeric($key)) {
$array[] = $this->parseKey($val);
}else{
$array[] = $this->parseKey($key).' '.$val;
}
}
$order = implode(',',$array);
}
return !empty($order)? ' ORDER BY '.$order:'';
}
/**
* group分析
* @access protected
* @param mixed $group
* @return string
*/
protected function parseGroup($group) {
return !empty($group)? ' GROUP BY '.$group:'';
}
/**
* having分析
* @access protected
* @param string $having
* @return string
*/
protected function parseHaving($having) {
return !empty($having)? ' HAVING '.$having:'';
}
/**
* comment分析
* @access protected
* @param string $comment
* @return string
*/
protected function parseComment($comment) {
return !empty($comment)? ' /* '.$comment.' */':'';
}
/**
* distinct分析
* @access protected
* @param mixed $distinct
* @return string
*/
protected function parseDistinct($distinct) {
return !empty($distinct)? ' DISTINCT ' :'';
}
/**
* union分析
* @access protected
* @param mixed $union
* @return string
*/
protected function parseUnion($union) {
if(empty($union)) return '';
if(isset($union['_all'])) {
$str = 'UNION ALL ';
unset($union['_all']);
}else{
$str = 'UNION ';
}
foreach ($union as $u){
$sql[] = $str.(is_array($u)?$this->buildSelectSql($u):$u);
}
return implode(' ',$sql);
}
/**
* 参数绑定分析
* @access protected
* @param array $bind
* @return array
*/
protected function parseBind($bind){
$this->bind = array_merge($this->bind,$bind);
}
/**
* index分析，可在操作链中指定需要强制使用的索引
* @access protected
* @param mixed $index
* @return string
*/
protected function parseForce($index) {
if(empty($index)) return '';
if(is_array($index)) $index = join(",", $index);
return sprintf(" FORCE INDEX ( %s ) ", $index);
}
/**
* ON DUPLICATE KEY UPDATE 分析
* @access protected
* @param mixed $duplicate
* @return string
*/
protected function parseDuplicate($duplicate){
return '';
}
/**
* 插入记录
* @access public
* @param mixed $data 数据
* @param array $options 参数表达式
* @param boolean $replace 是否replace
* @return false | integer
*/
public function insert($data,$options=array(),$replace=false) {
$values = $fields = array();
$this->model = $options['model'];
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
foreach ($data as $key=>$val){
if(is_array($val) && 'exp' == $val[0]){
$fields[] = $this->parseKey($key);
$values[] = $val[1];
}elseif(is_null($val)){
$fields[] = $this->parseKey($key);
$values[] = 'NULL';
}elseif(is_scalar($val)) { // 过滤非标量数据
$fields[] = $this->parseKey($key);
if(0===strpos($val,':') && in_array($val,array_keys($this->bind))){
$values[] = $this->parseValue($val);
}else{
$name = count($this->bind);
$values[] = ':'.$name;
$this->bindParam($name,$val);
}
}
}
// 兼容数字传入方式
$replace= (is_numeric($replace) && $replace>0)?true:$replace;
$sql = (true===$replace?'REPLACE':'INSERT').' INTO '.$this->parseTable($options['table']).' ('.implode(',', $fields).') VALUES ('.implode(',', $values).')'.$this->parseDuplicate($replace);
$sql .= $this->parseComment(!empty($options['comment'])?$options['comment']:'');
return $this->execute($sql,!empty($options['fetch_sql']) ? true : false);
}
/**
* 批量插入记录
* @access public
* @param mixed $dataSet 数据集
* @param array $options 参数表达式
* @param boolean $replace 是否replace
* @return false | integer
*/
public function insertAll($dataSet,$options=array(),$replace=false) {
$values = array();
$this->model = $options['model'];
if(!is_array($dataSet[0])) return false;
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
$fields = array_map(array($this,'parseKey'),array_keys($dataSet[0]));
foreach ($dataSet as $data){
$value = array();
foreach ($data as $key=>$val){
if(is_array($val) && 'exp' == $val[0]){
$value[] = $val[1];
}elseif(is_null($val)){
$value[] = 'NULL';
}elseif(is_scalar($val)){
if(0===strpos($val,':') && in_array($val,array_keys($this->bind))){
$value[] = $this->parseValue($val);
}else{
$name = count($this->bind);
$value[] = ':'.$name;
$this->bindParam($name,$val);
}
}
}
$values[] = 'SELECT '.implode(',', $value);
}
$sql = 'INSERT INTO '.$this->parseTable($options['table']).' ('.implode(',', $fields).') '.implode(' UNION ALL ',$values);
$sql .= $this->parseComment(!empty($options['comment'])?$options['comment']:'');
return $this->execute($sql,!empty($options['fetch_sql']) ? true : false);
}
/**
* 通过Select方式插入记录
* @access public
* @param string $fields 要插入的数据表字段名
* @param string $table 要插入的数据表名
* @param array $option 查询数据参数
* @return false | integer
*/
public function selectInsert($fields,$table,$options=array()) {
$this->model = $options['model'];
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
if(is_string($fields)) $fields = explode(',',$fields);
array_walk($fields, array($this, 'parseKey'));
$sql = 'INSERT INTO '.$this->parseTable($table).' ('.implode(',', $fields).') ';
$sql .= $this->buildSelectSql($options);
return $this->execute($sql,!empty($options['fetch_sql']) ? true : false);
}
/**
* 更新记录
* @access public
* @param mixed $data 数据
* @param array $options 表达式
* @return false | integer
*/
public function update($data,$options) {
$this->model = $options['model'];
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
$table = $this->parseTable($options['table']);
$sql = 'UPDATE ' . $table . $this->parseSet($data);
if(strpos($table,',')){// 多表更新支持JOIN操作
$sql .= $this->parseJoin(!empty($options['join'])?$options['join']:'');
}
$sql .= $this->parseWhere(!empty($options['where'])?$options['where']:'');
if(!strpos($table,',')){
// 单表更新支持order和lmit
$sql .= $this->parseOrder(!empty($options['order'])?$options['order']:'')
.$this->parseLimit(!empty($options['limit'])?$options['limit']:'');
}
$sql .= $this->parseComment(!empty($options['comment'])?$options['comment']:'');
return $this->execute($sql,!empty($options['fetch_sql']) ? true : false);
}
/**
* 删除记录
* @access public
* @param array $options 表达式
* @return false | integer
*/
public function delete($options=array()) {
$this->model = $options['model'];
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
$table = $this->parseTable($options['table']);
$sql = 'DELETE FROM '.$table;
if(strpos($table,',')){// 多表删除支持USING和JOIN操作
if(!empty($options['using'])){
$sql .= ' USING '.$this->parseTable($options['using']).' ';
}
$sql .= $this->parseJoin(!empty($options['join'])?$options['join']:'');
}
$sql .= $this->parseWhere(!empty($options['where'])?$options['where']:'');
if(!strpos($table,',')){
// 单表删除支持order和limit
$sql .= $this->parseOrder(!empty($options['order'])?$options['order']:'')
.$this->parseLimit(!empty($options['limit'])?$options['limit']:'');
}
$sql .= $this->parseComment(!empty($options['comment'])?$options['comment']:'');
return $this->execute($sql,!empty($options['fetch_sql']) ? true : false);
}
/**
* 查找记录
* @access public
* @param array $options 表达式
* @return mixed
*/
public function select($options=array()) {
$this->model = $options['model'];
$this->parseBind(!empty($options['bind'])?$options['bind']:array());
$sql = $this->buildSelectSql($options);
$result = $this->query($sql,!empty($options['fetch_sql']) ? true : false);
return $result;
}
/**
* 生成查询SQL
* @access public
* @param array $options 表达式
* @return string
*/
public function buildSelectSql($options=array()) {
if(isset($options['page'])) {
// 根据页数计算limit
list($page,$listRows) = $options['page'];
$page = $page>0 ? $page : 1;
$listRows= $listRows>0 ? $listRows : (is_numeric($options['limit'])?$options['limit']:20);
$offset = $listRows*($page-1);
$options['limit'] = $offset.','.$listRows;
}
$sql = $this->parseSql($this->selectSql,$options);
return $sql;
}
/**
* 替换SQL语句中表达式
* @access public
* @param array $options 表达式
* @return string
*/
public function parseSql($sql,$options=array()){
$sql = str_replace(
array('%TABLE%','%DISTINCT%','%FIELD%','%JOIN%','%WHERE%','%GROUP%','%HAVING%','%ORDER%','%LIMIT%','%UNION%','%LOCK%','%COMMENT%','%FORCE%'),
array(
$this->parseTable($options['table']),
$this->parseDistinct(isset($options['distinct'])?$options['distinct']:false),
$this->parseField(!empty($options['field'])?$options['field']:'*'),
$this->parseJoin(!empty($options['join'])?$options['join']:''),
$this->parseWhere(!empty($options['where'])?$options['where']:''),
$this->parseGroup(!empty($options['group'])?$options['group']:''),
$this->parseHaving(!empty($options['having'])?$options['having']:''),
$this->parseOrder(!empty($options['order'])?$options['order']:''),
$this->parseLimit(!empty($options['limit'])?$options['limit']:''),
$this->parseUnion(!empty($options['union'])?$options['union']:''),
$this->parseLock(isset($options['lock'])?$options['lock']:false),
$this->parseComment(!empty($options['comment'])?$options['comment']:''),
$this->parseForce(!empty($options['force'])?$options['force']:'')
),$sql);
return $sql;
}
/**
* 获取最近一次查询的sql语句
* @param string $model 模型名
* @access public
* @return string
*/
public function getLastSql($model='') {
return $model?$this->modelSql[$model]:$this->queryStr;
}
/**
* 获取最近插入的ID
* @access public
* @return string
*/
public function getLastInsID() {
return $this->lastInsID;
}
/**
* 获取最近的错误信息
* @access public
* @return string
*/
public function getError() {
return $this->error;
}
/**
* SQL指令安全过滤
* @access public
* @param string $str SQL字符串
* @return string
*/
public function escapeString($str) {
return addslashes($str);
}
/**
* 设置当前操作模型
* @access public
* @param string $model 模型名
* @return void
*/
public function setModel($model){
$this->model = $model;
}
/**
* 数据库调试 记录当前SQL
* @access protected
* @param boolean $start 调试开始标记 true 开始 false 结束
*/
protected function debug($start) {
if($this->config['debug']) {// 开启数据库调试模式
if($start) {
G('queryStartTime');
}else{
$this->modelSql[$this->model] = $this->queryStr;
//$this->model = '_think_';
// 记录操作结束时间
G('queryEndTime');
trace($this->queryStr.' [ RunTime:'.G('queryStartTime','queryEndTime').'s ]','','SQL');
}
}
}
/**
* 初始化数据库连接
* @access protected
* @param boolean $master 主服务器
* @return void
*/
protected function initConnect($master=true) {
if(!empty($this->config['deploy']))
// 采用分布式数据库
$this->_linkID = $this->multiConnect($master);
else
// 默认单数据库
if ( !$this->_linkID ) $this->_linkID = $this->connect();
}
/**
* 连接分布式服务器
* @access protected
* @param boolean $master 主服务器
* @return void
*/
protected function multiConnect($master=false) {
// 分布式数据库配置解析
$_config['username'] = explode(',',$this->config['username']);
$_config['password'] = explode(',',$this->config['password']);
$_config['hostname'] = explode(',',$this->config['hostname']);
$_config['hostport'] = explode(',',$this->config['hostport']);
$_config['database'] = explode(',',$this->config['database']);
$_config['dsn'] = explode(',',$this->config['dsn']);
$_config['charset'] = explode(',',$this->config['charset']);
$m = floor(mt_rand(0,$this->config['master_num']-1));
// 数据库读写是否分离
if($this->config['rw_separate']){
// 主从式采用读写分离
if($master)
// 主服务器写入
$r = $m;
else{
if(is_numeric($this->config['slave_no'])) {// 指定服务器读
$r = $this->config['slave_no'];
}else{
// 读操作连接从服务器
$r = floor(mt_rand($this->config['master_num'],count($_config['hostname'])-1)); // 每次随机连接的数据库
}
}
}else{
// 读写操作不区分服务器
$r = floor(mt_rand(0,count($_config['hostname'])-1)); // 每次随机连接的数据库
}
if($m != $r ){
$db_master = array(
'username' => isset($_config['username'][$m])?$_config['username'][$m]:$_config['username'][0],
'password' => isset($_config['password'][$m])?$_config['password'][$m]:$_config['password'][0],
'hostname' => isset($_config['hostname'][$m])?$_config['hostname'][$m]:$_config['hostname'][0],
'hostport' => isset($_config['hostport'][$m])?$_config['hostport'][$m]:$_config['hostport'][0],
'database' => isset($_config['database'][$m])?$_config['database'][$m]:$_config['database'][0],
'dsn' => isset($_config['dsn'][$m])?$_config['dsn'][$m]:$_config['dsn'][0],
'charset' => isset($_config['charset'][$m])?$_config['charset'][$m]:$_config['charset'][0],
);
}
$db_config = array(
'username' => isset($_config['username'][$r])?$_config['username'][$r]:$_config['username'][0],
'password' => isset($_config['password'][$r])?$_config['password'][$r]:$_config['password'][0],
'hostname' => isset($_config['hostname'][$r])?$_config['hostname'][$r]:$_config['hostname'][0],
'hostport' => isset($_config['hostport'][$r])?$_config['hostport'][$r]:$_config['hostport'][0],
'database' => isset($_config['database'][$r])?$_config['database'][$r]:$_config['database'][0],
'dsn' => isset($_config['dsn'][$r])?$_config['dsn'][$r]:$_config['dsn'][0],
'charset' => isset($_config['charset'][$r])?$_config['charset'][$r]:$_config['charset'][0],
);
return $this->connect($db_config,$r,$r == $m ? false : $db_master);
}
/**
* 析构方法
* @access public
*/
public function __destruct() {
// 释放查询
if ($this->PDOStatement){
$this->free();
}
// 关闭连接
$this->close();
}
}