<?php

/**
 * mysql dao 工具类: 目的是提高写sql语句的效率,但是应该是涉及到sql开发的地方不会太多...
 * ver: 2017.05.25 由王刚导入并调试, 慢慢发展, 不着急推广.
 *      Ps.至于可用性和稳定性还差的远, 直接执行sql语句是最靠谱的方式.
 * 用法备注:
 * select 用法: 最后必须得有fetch/fetchall/fetchPairs/fetchGroup...
 *    $dao->select()->from('table')     // 必选
 *         ->where()->eq()/gt()/lt()    // 可选
 *         ->andwhere()->in()           // 可选
 *         ->orderby()                  // 可选
 *         ->limit()                    // 可选
 *         ->fetch*();                  // 必选
 * insert 用法: 最后必须得有exec()
 *    $dao->insert('table')     // 必选
 *        ->data(data)          // 必选 data 为['filed'=>value,...]或{'k':v,...}
 *        ->*check()            // 可选
 *        ->exec()              // 必选
 *  或 $dao->insert('table')
 *        ->set('filed')->eq(value)
 *        ->set()->eq()...
 *        ->exec()
 * update 用法: 必须得有data(),where()和exec()
 *     $dao->update('table')    // 必选
 *        ->data(change)        // 必选 change 为['filed'=>value,...]或{'k':v,...}
 *        ->*check()            // 可选
 *        ->where()->eq/lt/gt() // 必选
 *        ->andwhere()->eq/lt/gt()  // 可选
 *        ->exec()              // 必选
 *  或  *     $dao->update('table')  // 必选
 *        ->set('field')->eq(value)  // 必选
 *        ->set()->eq()...           // 可选
 *        ->*check()            // 可选
 *        ->where()->eq/lt/gt() // 必选
 *        ->andwhere()->eq/lt/gt()  // 可选
 *        ->exec()              // 必选
 * delete 用法: 必须得有exec
 *      $dao->delete()->from('table')         // 必选
 *          ->where('field')->eq/lt/gt(value) // 必选
 *          ->andwhere()->eq/gt/lt()...       // 可选
 *          ->exec()                          // 必选
 * 更多用法继续参考禅道项目中具体代码(本人(gwang)参考的7.0版本).
 * (http://dl.cnezsoft.com/zentao/7.0/ZenTaoPMS.7.0.stable.zip)
 *
 */
/**
 * The dao and sql class file of ZenTaoPHP framework.
 *
 * The author disclaims copyright to this source code.  In place of
 * a legal notice, here is a blessing:
 *
 *  May you do good and not evil.
 *  May you find forgiveness for yourself and forgive others.
 *  May you share freely, never taking more than you give.
 */

namespace loyalsoft;

use \PDO;
use \PDOException;

/**
 * DAO, data access object.
 *
 * @package framework
 */
class dao {
    /* Use these strang strings to avoid conflicting with these keywords in the sql body. */

    const WHERE = 'wHeRe';
    const GROUPBY = 'gRoUp bY';
    const HAVING = 'hAvInG';
    const ORDERBY = 'oRdEr bY';
    const LIMIT = 'lImiT';

    /**
     * The global dbh(database handler) object.
     *
     * @var object
     * @access protected
     */
    protected $dbh;

    /**
     * The global slaveDBH(database handler) object.
     * 从数据库, 主从架构, 主库写如, 从库查询
     * @var object
     * @access protected
     */
    protected $slaveDBH;

    /**
     * The sql object, used to creat the query sql.
     *
     * @var object
     * @access protected
     */
    public $sqlobj;

    /**
     * The table of current query.
     *
     * @var string
     * @access public
     */
    public $table;

    /**
     * The alias of $this->table.
     *
     * @var string
     * @access public
     */
    public $alias;

    /**
     * The fields will be returned.
     *
     * @var string
     * @access public
     */
    public $fields;

    /**
     * The query mode, raw or magic.
     *
     * This var is used to diff dao::from() with sql::from().
     *
     * @var string
     * @access public
     */
    public $mode;

    /**
     * The query method: insert, select, update, delete, replace.
     *
     * @var string
     * @access public
     */
    public $method;

    /**
     * The sql code of need repair table.
     *
     * @var string
     * @access public
     */
    public $repairCode = '|1034|1035|1194|1195|1459|';

    /**
     * The queries executed. Every query will be saved in this array.
     *
     * @var array
     * @access public
     */
    static public $querys = array();

    /**
     * The errors.
     *
     * @var array
     * @access public
     */
    static public $errors = array();

    /**
     * The construct method.
     *
     * @access public
     * @return void
     */
    public function __construct() {

    }

    /**
     * Connect to database.
     * @param assoc_array $config  配置
     * @access public
     * @return void
     */
    public function connectDB($config) {
        global $dbh, $slaveDBH;

        if (isset($config->paydb->host)) {
            $this->dbh = $dbh = $this->connectByPDO($config->paydb);
        }
        if (isset($config->slaveDB->host)) {
            $this->slaveDBH = $slaveDBH = $this->connectByPDO($config->slaveDB);
        }
    }

    /**
     * Connect database by PDO.
     *
     * @param  object    $params    the database params.
     * @access private
     * @return object|bool
     */
    private function connectByPDO($params) {
        if (!isset($params->driver)) {
            self::triggerError('no pdo driver defined, it should be mysql or sqlite', __FILE__, __LINE__, $exit = true);
        }
        if (!isset($params->user)) {
            return false;
        }
        if ($params->driver == 'mysql') {
            $dsn = "mysql:host={$params->host}; port={$params->port}; dbname={$params->name}";
        }
        try {
            $dbh = new \PDO($dsn, $params->user, $params->password, array(PDO::ATTR_PERSISTENT => $params->persistant));
            $dbh->exec("SET NAMES {$params->encoding}");

            /* If run on linux, set emulatePrepare and bufferQuery to true. */
            if (!isset($params->emulatePrepare) and PHP_OS == 'Linux') {
                $params->emulatePrepare = true;
            }
            if (!isset($params->bufferQuery) and PHP_OS == 'Linux') {
                $params->bufferQuery = true;
            }

            $dbh->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
            $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            if (isset($params->strictMode) and $params->strictMode == false) {
                $dbh->exec("SET @@sql_mode= ''");
            }
            if (isset($params->emulatePrepare)) {
                $dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, $params->emulatePrepare);
            }
            if (isset($params->bufferQuery)) {
                $dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, $params->bufferQuery);
            }

            return $dbh;
        } catch (PDOException $exception) {
            self::triggerError($exception->getMessage(), __FILE__, __LINE__, $exit = true);
        }
    }

    /**
     * Set the $table property.
     *
     * @param  string $table
     * @access private
     * @return void
     */
    private function setTable($table) {
        $this->table = $table;
    }

    /**
     * Set the $alias property.
     *
     * @param  string $alias
     * @access private
     * @return void
     */
    private function setAlias($alias) {
        $this->alias = $alias;
    }

    /**
     * Set the $fields property.
     *
     * @param  string $fields
     * @access private
     * @return void
     */
    private function setFields($fields) {
        $this->fields = $fields;
    }

    /**
     * Reset the vars.
     *
     * @access private
     * @return void
     */
    private function reset() {
        $this->setFields('');
        $this->setTable('');
        $this->setAlias('');
        $this->setMode('');
        $this->setMethod('');
    }

//-------------------- According to the query method, call according method of sql class. --------------------//

    /**
     * Set the query mode. If the method if like findByxxx, the mode is magic. Else, the mode is raw.
     *
     * @param  string $mode     magic|raw
     * @access private
     * @return void
     */
    private function setMode($mode = '') {
        $this->mode = $mode;
    }

    /**
     * Set the query method: select|update|insert|delete|replace
     *
     * @param  string $method
     * @access private
     * @return void
     */
    private function setMethod($method = '') {
        $this->method = $method;
    }

    /**
     * The select method, call sql::select().
     *
     * @param  string $fields
     * @access public
     * @return object the dao object self.
     */
    public function select($fields = '*') {
        $this->setMode('raw');
        $this->setMethod('select');
        $this->sqlobj = sql::select($fields);
        return $this;
    }

    /**
     * The count method, call sql::select() and from().
     * use as $this->dao->select()->from(TABLE_BUG)->where()->count();
     *
     * @access public
     * @return void
     */
    public function count() {
        /* Get the SELECT, FROM position, thus get the fields, replace it by count(*). */
//        $this->fields
        $sql = $this->processSQL();
        $sql = str_replace('SELECT', 'SELECT SQL_CALC_FOUND_ROWS ', $sql);

        /* Remove the part after order and limit. */
        $subLength = strlen($sql);
        $orderPOS = strripos($sql, DAO::ORDERBY);
        $limitPOS = strripos($sql, DAO::LIMIT);
        if ($limitPOS) {
            $subLength = $limitPOS;
        }
        if ($orderPOS) {
            $subLength = $orderPOS;
        }
        $sql = substr($sql, 0, $subLength);
        self::$querys[] = $sql;

        /* Get the records count. */
        try {
            $row = $this->dbh->query($sql)->fetch(PDO::FETCH_OBJ);
        } catch (\PDOException $e) {
            $this->sqlError($e);
        }
//        CLogUtil_HP::paylog($sql);
//        var_dump($row);
        $sql = 'SELECT FOUND_ROWS() as recTotal;';
        $row = $this->dbh->query($sql)->fetch();

        return $row->recTotal;
    }

    /**
     * The select method, call sql::update().
     *
     * @param  string $table
     * @access public
     * @return object the dao object self.
     */
    public function update($table) {
        $this->setMode('raw');
        $this->setMethod('update');
        $this->sqlobj = sql::update($table);
        $this->setTable($table);
        return $this;
    }

    /**
     * The delete method, call sql::delete().
     *
     * @access public
     * @return object the dao object self.
     */
    public function delete() {
        $this->setMode('raw');
        $this->setMethod('delete');
        $this->sqlobj = sql::delete();
        return $this;
    }

    /**
     * The insert method, call sql::insert().
     *
     * @param  string $table
     * @access public
     * @return object the dao object self.
     */
    public function insert($table) {
        $this->setMode('raw');
        $this->setMethod('insert');
        $this->sqlobj = sql::insert($table);
        $this->setTable($table);
        return $this;
    }
    
    /**
     * The insert method, call sql::insert().
     *
     * @param  string $table
     * @access public
     * @return object the dao object self.
     */
    public function del($table) {
        $this->setMode('raw');
        $this->setMethod('DELETE');
        $this->sqlobj = sql::del($table);
        $this->setTable($table);
        return $this;
    }

    /**
     * The replace method, call sql::replace().
     *
     * @param  string $table
     * @access public
     * @return object the dao object self.
     */
    public function replace($table) {
        $this->setMode('raw');
        $this->setMethod('replace');
        $this->sqlobj = sql::replace($table);
        $this->setTable($table);
        return $this;
    }

    /**
     * Set the from table.
     *
     * @param  string $table
     * @access public
     * @return object the dao object self.
     */
    public function from($table) {
        $this->setTable($table);
        if ($this->mode == 'raw') {
            $this->sqlobj->from($table);
        }
        return $this;
    }

    /**
     * Set the fields.
     *
     * @param  string $fields
     * @access public
     * @return object the dao object self.
     */
    public function fields($fields) {
        $this->setFields($fields);
        return $this;
    }

    /**
     * Alias a table, equal the AS keyword. (Don't use AS, because it's a php keyword.)
     *
     * @param  string $alias
     * @access public
     * @return object the dao object self.
     */
    public function alias($alias) {
        if (empty($this->alias)) {
            $this->setAlias($alias);
        }
        $this->sqlobj->alias($alias);
        return $this;
    }

    /**
     * Set the data to update or insert.(注意: 只能支持单条数据的插入或者更新 -王刚)
     *
     * @param  object $data         the data object or array
     * @access public
     * @return object the dao object self.
     */
    public function data($data) {
        if (!is_object($data)) {
            $data = (object) $data;
        }
        $this->sqlobj->data($data);
        return $this;
    }

//-------------------- The sql related method. --------------------//

    /**
     * Get the sql string.
     *
     * @access public
     * @return string the sql string after process.
     */
    public function get() {
        return $this->processKeywords($this->processSQL());
    }

    /**
     * Print the sql string.
     *
     * @access public
     * @return void
     */
    public function printSQL() {
        echo $this->processSQL();
    }

    /**
     * Process the sql, replace the table, fields.
     *
     * @access private
     * @return string the sql string after process.
     */
    private function processSQL() {
        $sql = $this->sqlobj->get();

        /* If the mode is magic, process the $fields and $table. */
        if ($this->mode == 'magic') {
            if ($this->fields == '') {
                $this->fields = '*';
            }
            if ($this->table == '') {
                $this->triggerError('Must set the table name', __FILE__, __LINE__, $exit = true);
            }
            $sql = sprintf($this->sqlobj->get(), $this->fields, $this->table);
        }

        self::$querys[] = $this->processKeywords($sql);
        return $sql;
    }

    /**
     * Trriger an error.
     *
     * @param string    $message    error message
     * @param string    $file       the file error occers
     * @param int       $line       the line error occers
     * @param bool      $exit       exit the program or not
     * @access public
     * @return void
     */
    private function triggerError($message, $file, $line, $exit = false) {
        /* Set the error info. */
        $log = "ERROR: " . CommUtil::str2UTF8($message) . " in " . CommUtil::str2UTF8($file) . " on line $line";
        if (isset($_SERVER['SCRIPT_URI'])) {
            $log .= ", request: $_SERVER[SCRIPT_URI]";
        }
        $trace = debug_backtrace();
        extract($trace[0]);                        # function
        extract($trace[1]);                        # line
        $log .= ", last called by $file on line $line through function $function.\n";

        CLog::err($log, "dao");
        CLog::err($trace, "dao");
        /* Trigger it. */
        trigger_error($log, $exit ? E_USER_ERROR : E_USER_WARNING);
    }

    /**
     * Process the sql keywords, replace the constants to normal.
     *
     * @param  string $sql
     * @access private
     * @return string the sql string.
     */
    private function processKeywords($sql) {
        return str_replace(array(DAO::WHERE, DAO::GROUPBY, DAO::HAVING, DAO::ORDERBY, DAO::LIMIT), array('WHERE', 'GROUP BY', 'HAVING', 'ORDER BY', 'LIMIT'), $sql);
    }

//-------------------- Query related methods. --------------------//

    /**
     * Set the dbh.
     *
     * You can use like this: $this->dao->dbh($dbh), thus you can handle two database.
     *
     * @param  object $dbh
     * @access public
     * @return object the dao object self.
     */
    public function dbh($dbh) {
        $this->dbh = $dbh;
        return $this;
    }

    /**
     * Query the sql, return the statement object.
     *
     * @param  string $sql
     * @access public
     * @return object   the PDOStatement object.
     */
    public function query($sql = '') {
        if (!empty(dao::$errors)) {
            return new PDOStatement();   // If any error, return an empty statement object to make sure the remain method to execute.
        }

        if ($sql) {
            if (is_null($this->sqlobj)) {
                $this->sqlobj = sql::factory();
            }
            $this->sqlobj->sql = $sql;
        }
        $sql = $this->processSQL();

        try {
            $method = $this->method;
            $this->reset();
//            var_dump($sql);
            if ($this->slaveDBH and $method == 'select') {
                return $this->slaveDBH->query($sql);
            } else {
                return $this->dbh->query($sql);
            }
        } catch (\PDOException $e) {
            $this->sqlError($e);
        }
    }

    /**
     * Page the records, set the limit part auto.
     *
     * @param  object $pager
     * @access public
     * @return object the dao object self.
     */
    public function page($pager) {
        if (!is_object($pager)) {
            return $this;
        }

        /* If the record total is 0, compute it. */
        if ($pager->recTotal == 0) {
            /* Get the SELECT, FROM position, thus get the fields, replace it by count(*). */
            $sql = $this->get();
            $selectPOS = strpos($sql, 'SELECT') + strlen('SELECT');
            $fromPOS = strpos($sql, 'FROM');
            $fields = substr($sql, $selectPOS, $fromPOS - $selectPOS);
            $sql = str_replace($fields, ' COUNT(*) AS recTotal ', $sql);

            /* Remove the part after order and limit. */
            $subLength = strlen($sql);
            $orderPOS = strripos($sql, 'order ');
            $limitPOS = strripos($sql, 'limit');
            if ($limitPOS) {
                $subLength = $limitPOS;
            }
            if ($orderPOS) {
                $subLength = $orderPOS;
            }
            $sql = substr($sql, 0, $subLength);
            self::$querys[] = $sql;

            /* Get the records count. */
            try {
                $row = $this->dbh->query($sql)->fetch(PDO::FETCH_OBJ);
            } catch (\PDOException $e) {
                $this->sqlError($e);
            }

            $pager->setRecTotal($row->recTotal);
            $pager->setPageTotal();
        }
        $this->sqlobj->limit($pager->limit());
        return $this;
    }

    /**
     * 字符串引号处理
     * @param type $str
     * @param type $parameter_type
     * @return type
     */
    public function quote($str, $parameter_type = PDO::PARAM_STR) {
        return $this->dbh->quote($str, $parameter_type);
    }

    /**
     * Execute the sql. It's different with query(), which return the stmt object. But this not.
     *
     * @param  string $sql
     * @access public
     * @return int the modified or deleted records.
     */
    public function exec($sql = '') {
        if (!empty(dao::$errors)) {
            return new PDOStatement();   // If any error, return an empty statement object to make sure the remain method to execute.
        }
        if ($sql) {
            if (is_null($this->sqlobj)) {
                $this->sqlobj = sql::factory();
            }
            $this->sqlobj->sql = $sql;
        }
        $sql = $this->processSQL();

//        var_dump($sql);
        try {
            $this->reset();
            return $this->dbh->exec($sql);
        } catch (\PDOException $e) {
            $this->sqlError($e);
        }
    }

//-------------------- Fetch related methods. -------------------//

    /**
     * Fetch one record.
     *
     * @param  string $field        if the field is set, only return the value of this field, else return this record
     * @access public
     * @return object|mixed
     */
    public function fetch($field = '') {
        if (empty($field)) {
            return $this->query()->fetch();
        }
        $this->setFields($field);
        $result = $this->query()->fetch(PDO::FETCH_OBJ);
        if ($result) {
            return $result->$field;
        }
        return false;
    }

    /**
     * Fetch all records.
     *
     * @param  string $keyField     the key field, thus the return records is keyed by this field
     * @access public
     * @return array the records
     */
    public function fetchAll($keyField = '') {

        $stmt = $this->query();

        if (empty($keyField)) {
            return $stmt->fetchAll();
        }
        $rows = array();
        while ($row = $stmt->fetch()) {
            $rows[$row->$keyField] = $row;
        }
        return $rows;
    }

    /**
     * Fetch all records and group them by one field.
     *
     * @param  string $groupField   the field to group by
     * @param  string $keyField     the field of key
     * @access public
     * @return array the records.
     */
    public function fetchGroup($groupField, $keyField = '') {
        $stmt = $this->query();
        $rows = array();
        while ($row = $stmt->fetch()) {
            empty($keyField) ? $rows[$row->$groupField][] = $row : $rows[$row->$groupField][$row->$keyField] = $row;
        }
        return $rows;
    }

    /**
     * Fetch array like key=>value.
     *
     * If the keyFiled and valueField not set, use the first and last in the record.
     *
     * @param  string $keyField
     * @param  string $valueField
     * @access public
     * @return array
     */
    public function fetchPairs($keyField = '', $valueField = '') {
        $pairs = array();
        $ready = false;
        $stmt = $this->query();
        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
            if (!$ready) {
                if (empty($keyField)) {
                    $keyField = key($row);
                }
                if (empty($valueField)) {
                    end($row);
                    $valueField = key($row);
                }
                $ready = true;
            }

            $pairs[$row[$keyField]] = $row[$valueField];
        }
        return $pairs;
    }

    /**
     * Return the last insert ID.
     *
     * @access public
     * @return int
     */
    public function lastInsertID() {
        return $this->dbh->lastInsertID();
    }

//-------------------- Magic methods.--------------------//

    /**
     * Use it to do some convenient queries.
     *
     * @param  string $funcName  the function name to be called
     * @param  array  $funcArgs  the params
     * @access public
     * @return object the dao object self.
     */
    public function __call($funcName, $funcArgs) {
        $funcName = strtolower($funcName);

        /* findByxxx, xxx as will be in the where. */
        if (strpos($funcName, 'findby') !== false) {
            $this->setMode('magic');
            $field = str_replace('findby', '', $funcName);
            if (count($funcArgs) == 1) {
                $operator = '=';
                $value = $funcArgs[0];
            } else {
                $operator = $funcArgs[0];
                $value = $funcArgs[1];
            }
            $this->sqlobj = sql::select('%s')->from('%s')->where($field, $operator, $value);
            return $this;
        }
        /* Fetch10. */ elseif (strpos($funcName, 'fetch') !== false) {
            $max = str_replace('fetch', '', $funcName);
            $stmt = $this->query();

            $rows = array();
            $key = isset($funcArgs[0]) ? $funcArgs[0] : '';
            $i = 0;
            while ($row = $stmt->fetch()) {
                $key ? $rows[$row->$key] = $row : $rows[] = $row;
                $i++;
                if ($i == $max) {
                    break;
                }
            }
            return $rows;
        }
        /* Others, call the method in sql class. */ else {
            /* Create the max counts of sql class methods, and then create $arg0, $arg1... */
            for ($i = 0; $i < SQL::MAX_ARGS; $i++) {
                ${"arg$i"} = isset($funcArgs[$i]) ? $funcArgs[$i] : null;
            }
            $this->sqlobj->$funcName($arg0, $arg1, $arg2);
            return $this;
        }
    }

//-------------------- Checking.--------------------//

    /**
     * Check a filed is satisfied with the check rule.
     *
     * @param  string $fieldName    the field to check
     * @param  string $funcName     the check rule
     * @access public
     * @return object the dao object self.
     */
    public function check($fieldName, $funcName) {
        /* If no this field in the data, reuturn. */
        if (!isset($this->sqlobj->data->$fieldName)) {
            return $this;
        }
        /* Set the field label and value. */
        global $lang, $config, $app;
        $table = strtolower(str_replace(array($config->db->prefix, '`'), '', $this->table));
        $fieldLabel = isset($lang->$table->$fieldName) ? $lang->$table->$fieldName : $fieldName;
        $value = $this->sqlobj->data->$fieldName;

        /* Check unique. */
        if ($funcName == 'unique') {
            $args = func_get_args();
            $sql = "SELECT COUNT(*) AS count FROM $this->table WHERE `$fieldName` = " . $this->sqlobj->quote($value);
            if (isset($args[2])) {
                $sql .= ' AND ' . $args[2];
            }
            try {
                $row = $this->dbh->query($sql)->fetch();
                if ($row->count != 0) {
                    $this->logError($funcName, $fieldName, $fieldLabel, array($value));
                }
            } catch (PDOException $e) {
                $this->sqlError($e);
            }
        } else {
            /* Create the params. */
            $funcArgs = func_get_args();
            unset($funcArgs[0]);
            unset($funcArgs[1]);

            for ($i = 0; $i < VALIDATER::MAX_ARGS; $i++) {
                ${"arg$i"} = isset($funcArgs[$i + 2]) ? $funcArgs[$i + 2] : null;
            }
            $checkFunc = 'check' . $funcName;
            if (validater::$checkFunc($value, $arg0, $arg1, $arg2) === false) {
                $this->logError($funcName, $fieldName, $fieldLabel, $funcArgs);
            }
        }

        return $this;
    }

    /**
     * Check a field, if satisfied with the condition.
     *
     * @param  string $condition
     * @param  string $fieldName
     * @param  string $funcName
     * @access public
     * @return object the dao object self.
     */
    public function checkIF($condition, $fieldName, $funcName) {
        if (!$condition) {
            return $this;
        }
        $funcArgs = func_get_args();
        for ($i = 0; $i < VALIDATER::MAX_ARGS; $i++) {
            ${"arg$i"} = isset($funcArgs[$i + 3]) ? $funcArgs[$i + 3] : null;
        }
        $this->check($fieldName, $funcName, $arg0, $arg1, $arg2);
        return $this;
    }

    /**
     * Batch check some fileds.
     *
     * @param  string $fields       the fields to check, join with ,
     * @param  string $funcName
     * @access public
     * @return object the dao object self.
     */
    public function batchCheck($fields, $funcName) {
        $fields = explode(',', str_replace(' ', '', $fields));
        $funcArgs = func_get_args();
        for ($i = 0; $i < VALIDATER::MAX_ARGS; $i++) {
            ${"arg$i"} = isset($funcArgs[$i + 2]) ? $funcArgs[$i + 2] : null;
        }
        foreach ($fields as $fieldName) {
            $this->check($fieldName, $funcName, $arg0, $arg1, $arg2);
        }
        return $this;
    }

    /**
     * Batch check fields on the condition is true.
     *
     * @param  string $condition
     * @param  string $fields
     * @param  string $funcName
     * @access public
     * @return object the dao object self.
     */
    public function batchCheckIF($condition, $fields, $funcName) {
        if (!$condition) {
            return $this;
        }
        $fields = explode(',', str_replace(' ', '', $fields));
        $funcArgs = func_get_args();
        for ($i = 0; $i < VALIDATER::MAX_ARGS; $i++) {
            ${"arg$i"} = isset($funcArgs[$i + 2]) ? $funcArgs[$i + 2] : null;
        }
        foreach ($fields as $fieldName) {
            $this->check($fieldName, $funcName, $arg0, $arg1, $arg2);
        }
        return $this;
    }

    /**
     * Check the fields according the the database schema.
     *
     * @param  string $skipFields   fields to skip checking
     * @access public
     * @return object the dao object self.
     */
    public function autoCheck($skipFields = '') {
        $fields = $this->getFieldsType();
        $skipFields = ",$skipFields,";

        foreach ($fields as $fieldName => $validater) {
            if (strpos($skipFields, $fieldName) !== false) {
                continue; // skip it.
            }
            if (!isset($this->sqlobj->data->$fieldName)) {
                continue;
            }
            if ($validater['rule'] == 'skip') {
                continue;
            }
            $options = array();
            if (isset($validater['options'])) {
                $options = array_values($validater['options']);
            }
            for ($i = 0; $i < VALIDATER::MAX_ARGS; $i++) {
                ${"arg$i"} = isset($options[$i]) ? $options[$i] : null;
            }
            $this->check($fieldName, $validater['rule'], $arg0, $arg1, $arg2);
        }
        return $this;
    }

    /**
     * 检查表是否存在
     * @param type $tableName
     * @return type
     */
    public function tableExist($tableName) {
        $this->reset();
        $this->setMethod('select');
        $sql = "SELECT 1 FROM `$tableName` LIMIT 1";
        $ret = false;
        try {
            if ($this->slaveDBH and $this->method == 'select') {
                $ret = $this->slaveDBH->query($sql)->fetchAll();
            } else {
                $ret = $this->dbh->query($sql)->fetchAll();
            }
        } catch (\Exception $exc) {                                             # 表不存在的时候直接进异常处理逻辑.
            CLog::err($exc->getMessage());
            return false;
        }
        // Result is either boolean FALSE (no table found) or PDOStatement Object (table found)
        return $ret !== FALSE;                                                  # false代表表不存在
    }

    public function Ping() {
        try {
            $this->dbh->getAttribute(PDO::ATTR_SERVER_INFO);
        } catch (\PDOException $e) {
            if (strpos($e->getMessage(), 'MySQL server has gone away') !== false) {
                return false;
            }
        }
        return true;
    }

    /**
     * Log the error.
     *
     * For the error notice, see module/common/lang.
     *
     * @param  string $checkType    the check rule
     * @param  string $fieldName    the field name
     * @param  string $fieldLabel   the field label
     * @param  array  $funcArgs     the args
     * @access public
     * @return void
     */
    public function logError($checkType, $fieldName, $fieldLabel, $funcArgs = array()) {
        global $lang;
        $error = $lang->error->$checkType;
        $replaces = array_merge(array($fieldLabel), $funcArgs);     // the replace values.

        /* Just a string, cycle the $replaces. */
        if (!is_array($error)) {
            foreach ($replaces as $replace) {
                $pos = strpos($error, '%s');
                if ($pos === false) {
                    break;
                }
                $error = substr($error, 0, $pos) . $replace . substr($error, $pos + 2);
            }
        } else {/* If the error define is an array, select the one which %s counts match the $replaces.  */
            /* Remove the empty items. */
            foreach ($replaces as $key => $value) {
                if (is_null($value)) {
                    unset($replaces[$key]);
                }
            }
            $replacesCount = count($replaces);
            foreach ($error as $errorString) {
                if (substr_count($errorString, '%s') == $replacesCount) {
                    $error = vsprintf($errorString, $replaces);
                }
            }
        }
        dao::$errors[$fieldName][] = $error;
    }

    /**
     * Judge any error or not.
     *
     * @access public
     * @return bool
     */
    public static function isError() {
        return !empty(dao::$errors);
    }

    /**
     * Get the errors.
     *
     * @param  boolean $join
     * @access public
     * @return array
     */
    public static function getError($join = false) {
        $errors = dao::$errors;
        dao::$errors = array();                                                 # Must clear it.

        if (!$join) {
            return $errors;
        }
        if (is_array($errors)) {
            $message = '';
            foreach ($errors as $item) {
                is_array($item) ? $message .= join('\n', $item) . '\n' : $message .= $item . '\n';
            }
            return $message;
        }
    }

    /**
     * Get the defination of fields of the table.
     *
     * @access private
     * @return array
     */
    private function getFieldsType() {
        try {
            $this->dbh->setAttribute(PDO::ATTR_CASE, PDO::CASE_LOWER);
            $sql = "DESC $this->table";
            $rawFields = $this->dbh->query($sql)->fetchAll();
            $this->dbh->setAttribute(PDO::ATTR_CASE, PDO::CASE_NATURAL);
        } catch (\PDOException $e) {
            $this->sqlError($e);
        }

        foreach ($rawFields as $rawField) {
            $firstPOS = strpos($rawField->type, '(');
            $type = substr($rawField->type, 0, $firstPOS > 0 ? $firstPOS : strlen($rawField->type));
            $type = str_replace(array('big', 'small', 'medium', 'tiny', 'var'), '', $type);
            $field = array();

            if ($type == 'enum' or $type == 'set') {
                $rangeBegin = $firstPOS + 2;                       // Remove the first quote.
                $rangeEnd = strrpos($rawField->type, ')') - 1;   // Remove the last quote.
                $range = substr($rawField->type, $rangeBegin, $rangeEnd - $rangeBegin);
                $field['rule'] = 'reg';
                $field['options']['reg'] = '/' . str_replace("','", '|', $range) . '/';
            } elseif ($type == 'char') {
                $begin = $firstPOS + 1;
                $end = strpos($rawField->type, ')', $begin);
                $length = substr($rawField->type, $begin, $end - $begin);
                $field['rule'] = 'length';
                $field['options']['max'] = $length;
                $field['options']['min'] = 0;
            } elseif ($type == 'int') {
                $field['rule'] = 'int';
            } elseif ($type == 'float' or $type == 'double') {
                $field['rule'] = 'float';
            } elseif ($type == 'date') {
                $field['rule'] = 'date';
            } else {
                $field['rule'] = 'skip';
            }
            $fields[$rawField->field] = $field;
        }
        return $fields;
    }

    /**
     * Process SQL error by code.
     *
     * @param  object    $exception
     * @access public
     * @return void
     */
    public function sqlError($exception) {
        $errorInfo = $exception->errorInfo;
        $errorCode = $errorInfo[1];
        $errorMsg = $errorInfo[2];
        $message = $exception->getMessage();
        if (strpos($this->repairCode, "|$errorCode|") !== false  #
                or ( $errorCode == '1016' and strpos($errorMsg, 'errno: 145') !== false)) {
            $message .= ' repairTable';
        }
        $sql = $this->sqlobj->get();
        $this->triggerError($message . "<p>The sql is: $sql</p>", __FILE__, __LINE__, $exit = true);
    }

}

/**
 * The SQL class.
 *
 * @package framework
 */
class sql {

    /**
     * The max count of params of all methods.
     *
     */
    const MAX_ARGS = 3;

    /**
     * The sql string.
     *
     * @var string
     * @access public
     */
    public $sql = '';

    /**
     * The global $dbh.
     *
     *
     * @access protected
     */
    protected $dbh;

    /**
     * The data to update or insert.
     *
     * @var mix
     * @access protected
     */
    public $data;

    /**
     * Is the first time to  call set.
     *
     * @var bool
     * @access private;
     */
    private $isFirstSet = true;

    /**
     * If in the logic of judge condition or not.
     *
     * @var bool
     * @access private;
     */
    private $inCondition = false;

    /**
     * The condition is true or not.
     *
     * @var bool
     * @access private;
     */
    private $conditionIsTrue = false;

    /**
     * Magic quote or not.
     *
     * @var bool
     * @access public
     */
    public $magicQuote;

    /**
     * The construct function. user factory() to instance it.
     *
     * @param  string $table
     * @access private
     * @return void
     */
    private function __construct($table = '') {
        global $dbh;
        $this->dbh = $dbh;
        $this->magicQuote = false; // get_magic_quotes_gpc();
    }

    /**
     * The factory method.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public static function factory($table = '') {
        return new sql($table);
    }

    /**
     * The sql is select.
     *
     * @param  string $field
     * @access public
     * @return object the sql object.
     */
    public static function select($field = '*') {
        $sqlobj = self::factory();
        $sqlobj->sql = "SELECT $field ";
        return $sqlobj;
    }

    /**
     * The sql is update.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public static function update($table) {
        $sqlobj = self::factory();
        $sqlobj->sql = "UPDATE $table SET ";
        return $sqlobj;
    }

    /**
     * The sql is insert.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public static function insert($table) {
        $sqlobj = self::factory();
        $sqlobj->sql = "INSERT INTO $table SET ";
        return $sqlobj;
    }
    
    /**
     * The sql is insert.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public static function del($table) {
        $sqlobj = self::factory();     
        $sqlobj->sql = "DELETE FROM $table WHERE ";
        return $sqlobj;
    }

    /**
     * The sql is replace.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public static function replace($table) {
        $sqlobj = self::factory();
        $sqlobj->sql = "REPLACE $table SET ";
        return $sqlobj;
    }

    /**
     * The sql is delete.
     *
     * @access public
     * @return object the sql object.
     */
    public static function delete() {
        $sqlobj = self::factory();
        $sqlobj->sql = "DELETE ";
        return $sqlobj;
    }

    /**
     * Join the data items by key = value.
     *
     * @param  object $data
     * @access public
     * @return object the sql object.
     */
    public function data($data) {
        $data = (object) $data;

        foreach ($data as $field => $value) {
            if (!preg_match('|^\w+$|', $field)) {
                unset($data->$field);
                continue;
            }
            $this->sql .= "`$field` = " . $this->quote($value) . ',';
        }

        $this->data = $data;
        $this->sql = rtrim($this->sql, ',');    // Remove the last ','.
        return $this;
    }

    /**
     * Aadd an '(' at left.
     *
     * @param  int    $count
     * @access public
     * @return ojbect the sql object.
     */
    public function markLeft($count = 1) {
        $this->sql .= str_repeat('(', $count);
        return $this;
    }

    /**
     * Add an ')' ad right.
     *
     * @param  int    $count
     * @access public
     * @return object the sql object.
     */
    public function markRight($count = 1) {
        $this->sql .= str_repeat(')', $count);
        return $this;
    }

    /**
     * The set part.
     *
     * @param  string $set
     * @access public
     * @return object the sql object.
     */
    public function set($set) {
        if ($this->isFirstSet) {
            $this->sql .= " $set ";
            $this->isFirstSet = false;
        } else {
            $this->sql .= ", $set";
        }
        return $this;
    }

    /**
     * Create the from part.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public function from($table) {
        $this->sql .= "FROM $table";
        return $this;
    }

    /**
     * Create the Alias part.
     *
     * @param  string $alias
     * @access public
     * @return object the sql object.
     */
    public function alias($alias) {
        $this->sql .= " AS $alias ";
        return $this;
    }

    /**
     * Create the left join part.
     *
     * @param  string $table
     * @access public
     * @return object the sql object.
     */
    public function leftJoin($table) {
        $this->sql .= " LEFT JOIN $table";
        return $this;
    }

    /**
     * Create the on part.
     *
     * @param  string $condition
     * @access public
     * @return object the sql object.
     */
    public function on($condition) {
        $this->sql .= " ON $condition ";
        return $this;
    }

    /**
     * Begin condition judge.
     *
     * @param  bool $condition
     * @access public
     * @return object the sql object.
     */
    public function beginIF($condition) {
        $this->inCondition = true;
        $this->conditionIsTrue = $condition;
        return $this;
    }

    /**
     * End the condition judge.
     *
     * @access public
     * @return object the sql object.
     */
    public function fi() {
        $this->inCondition = false;
        $this->conditionIsTrue = false;
        return $this;
    }

    /**
     * Create the where part.
     *
     * @param  string $arg1     the field name
     * @param  string $arg2     the operator
     * @param  string $arg3     the value
     * @access public
     * @return object the sql object.
     */
    public function where($arg1, $arg2 = null, $arg3 = null) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        if ($arg3 !== null) {
            $value = $this->quote($arg3);
            $condition = "`$arg1` $arg2 " . $this->quote($arg3);
        } else {
            $condition = $arg1;
        }

        $this->sql .= ' ' . DAO::WHERE . " $condition ";
        return $this;
    }

    /**
     * Create the AND part.
     *
     * @param  string $condition
     * @access public
     * @return object the sql object.
     */
    public function andWhere($condition) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " AND $condition ";
        return $this;
    }

    /**
     * Create the OR part.
     *
     * @param  bool  $condition
     * @access public
     * @return object the sql object.
     */
    public function orWhere($condition) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " OR $condition ";
        return $this;
    }

    /**
     * Create the '='.
     *
     * @param  string $value
     * @access public
     * @return object the sql object.
     */
    public function eq($value) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " = " . $this->quote($value);
        return $this;
    }

    /**
     * Create '!='.
     *
     * @param  string $value
     * @access public
     * @return void the sql object.
     */
    public function ne($value) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " != " . $this->quote($value);
        return $this;
    }

    /**
     * Create '>'.
     *
     * @param  string $value
     * @access public
     * @return object the sql object.
     */
    public function gt($value) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " > " . $this->quote($value);
        return $this;
    }

    /**
     * Create '>='.
     *
     * @param  string $value
     * @access public
     * @return object the sql object.
     */
    public function ge($value) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " >= " . $this->quote($value);
        return $this;
    }

    /**
     * Create '<'.
     *
     * @param  mixed  $value
     * @access public
     * @return object the sql object.
     */
    public function lt($value) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " < " . $this->quote($value);

        return $this;
    }

    /**
     * Create '<='.
     *
     * @param  mixed  $value
     * @access public
     * @return object the sql object.
     */
    public function le($value) {
        if ($this->inCondition && !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " <= " . $this->quote($value);
        return $this;
    }

    /**
     * Create "between and"
     *
     * @param  string $min
     * @param  string $max
     * @access public
     * @return object the sql object.
     */
    public function between($min, $max) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $min = $this->quote($min);
        $max = $this->quote($max);
        $this->sql .= " BETWEEN $min AND $max ";
        return $this;
    }

    /**
     * Create in part.
     *
     * @param  string|array $ids   list string by ',' or an array
     * @access public
     * @return object the sql object.
     */
    public function in($ids) {
//        var_dump($ids);
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= self::dbIN($ids);
        return $this;
    }

    /**
     * Create the in('a', 'b') string.
     *
     * @param   string|array $ids   the id lists, can be a array or a string with ids joined with comma.
     * @static
     * @access  public
     * @return  string  the string like IN('a', 'b').
     */
    private static function dbIN($ids) {
        if (is_array($ids)) {
            return "IN ('" . join("','", $ids) . "')";
        }
        return "IN ('" . str_replace(',', "','", str_replace(' ', '', $ids)) . "')";
    }

    /**
     * Create not in part.
     *
     * @param  string|array $ids   list string by ',' or an array
     * @access public
     * @return object the sql object.
     */
    public function notin($ids) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= ' NOT ' . self::dbIN($ids);
        return $this;
    }

    /**
     * Create the like by part.
     *
     * @param  string $string
     * @access public
     * @return object the sql object.
     */
    public function like($string) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= " LIKE " . $this->quote($string);
        return $this;
    }

    /**
     * Create the not like by part.
     *
     * @param  string $string
     * @access public
     * @return object the sql object.
     */
    public function notLike($string) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= "NOT LIKE " . $this->quote($string);
        return $this;
    }

    /**
     * Create the find_in_set by part.
     *
     * @param  int    $str
     * @param  int    $strList
     * @access public
     * @return object the sql object.
     */
    public function findInSet($str, $strList) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }
        $this->sql .= "FIND_IN_SET(" . $str . "," . $strList . ")";
    }

    /**
     * Create the order by part.
     *
     * @param  string $order
     * @access public
     * @return object the sql object.
     */
    public function orderBy($order) {
        if ($this->inCondition and !$this->conditionIsTrue) {
            return $this;
        }

        $order = str_replace(array('|', '', '_'), ' ', $order);

        /* Add "`" in order string. */
        /* When order has limit string. */
        $pos = stripos($order, 'limit');
        $orders = $pos ? substr($order, 0, $pos) : $order;
        $limit = $pos ? substr($order, $pos) : '';

        $orders = explode(',', $orders);
        foreach ($orders as $i => $order) {
            $orderParse = explode(' ', trim($order));
            foreach ($orderParse as $key => $value) {
                $value = trim($value);
                if (empty($value) #
                        or strtolower($value) == 'desc' #
                        or strtolower($value) == 'asc') {
                    continue;
                }
                $field = trim($value, '`');

                /* such as t1.id field. */
                if (strpos($value, '.') !== false) {
                    list($table, $field) = explode('.', $field);
                }
                $field = "`$field`";

                $orderParse[$key] = isset($table) ? $table . '.' . $field : $field;
                unset($table);
            }
            $orders[$i] = join(' ', $orderParse);
        }
        $order = join(',', $orders) . ' ' . $limit;

        $this->sql .= ' ' . DAO::ORDERBY . " $order";
        return $this;
    }

    /**
     * Create the limit part.
     *
     * @param  string $limit
     * @access public
     * @return object the sql object.
     */
    public function limit($limit) {
        if (empty($limit)) {
            return $this;
        }
        stripos($limit, 'limit') !== false ? $this->sql .= " $limit " : $this->sql .= ' ' . DAO::LIMIT . " $limit ";
        return $this;
    }

    /**
     * Create the groupby part.
     *
     * @param  string $groupBy
     * @access public
     * @return object the sql object.
     */
    public function groupBy($groupBy) {
        $this->sql .= ' ' . DAO::GROUPBY . " $groupBy";
        return $this;
    }

    /**
     * Create the having part.
     *
     * @param  string $having
     * @access public
     * @return object the sql object.
     */
    public function having($having) {
        $this->sql .= ' ' . DAO::HAVING . " $having";
        return $this;
    }

    /**
     * Get the sql string.
     *
     * @access public
     * @return string
     */
    public function get() {
        return $this->sql;
    }

    /**
     * Uuote a var.
     *
     * @param  mixed  $value
     * @access public
     * @return mixed
     */
    public function quote($value) {
        if ($this->magicQuote) {
            $value = stripslashes($value);
        }
        if (!is_string($value)) {
            $value = "$value";
        }
        return $this->dbh->quote($value);
    }

}