php中pdo數據庫操作工具類

pdo中數據庫的CRUD操作

 基本能滿足一些小項目的要求

<?php


class PDOHelp
{
    private static $instance;
    public $dsn;
    public $sth;
    public $dbh;
    const DB_HOST = 'localhost';
    const DB_USER = 'root';
    const DB_PASS = '';

//    const DB_HOST = '192.168.1.250';
//    const DB_USER = 'root';
//    const DB_PASS = '123456';
    const DB_PORT = '9092';
    const DB_NAME = 'llsh';
    const DB_CHARSET = 'utf8';
    const PAGE_SIZE = 20;

    public function __construct()
    {
       // header("Content-Type:text/html; charset=utf-8");
        $this->dsn = 'mysql:host=' . self::DB_HOST . ';dbname=' . self::DB_NAME;
        $this->dbuser = self::DB_USER;
        $this->dbpass = self::DB_PASS;
        $this->connect();
        $this->dbh->query('SET NAMES ' . self::DB_CHARSET);
    }

    public static function getInstance()
    {
        if (self::$instance === null) {
            self::$instance = new PDOHelp();
        }
        return self::$instance;
    }

    //連接數據庫
    private function connect()
    {
        try {
            $this->dbh = new PDO($this->dsn, $this->dbuser, $this->dbpass);
        } catch (PDOException $e) {
            exit('連接失敗:' . $e->getMessage());
        }
    }

    //獲取數據表裏的字段
    public function getFields($table)
    {
        $this->sth = $this->dbh->query("DESCRIBE $table");
        $this->getPDOError();
        $this->sth->setFetchMode(PDO::FETCH_ASSOC);
        $result = $this->sth->fetchAll();
        $this->sth = null;
        return $result;
    }

    public function getAllTable()
    {
        $sql = "show tables";
        $rows = $this->doSql($sql);
        $tables = array();
        foreach ($rows as $row) {
            $items = array();
            $table = $row['Tables_in_' . self::DB_NAME];
            $sql = "show columns from  {$table}";
            $items = $this->doSql($sql);
            $columns = array();
            foreach ($items as $item) {
                $columns[] = $item['Field'];
            }
            $tables[$table] = $columns;
        }
        return $tables;
    }

    //獲取要操作的數據
    private function getCode($table, $args)
    {
        $allTables = $this->getAllTable();/*返回所有的表及其字段*/
        if (!is_array($allTables[$table])) {
            exit('表名錯誤或未更新緩存!');
        }
        $code = '';
        if (is_array($args)) {
            foreach ($args as $k => $v) {
                if ($v == '') {
                    continue;
                }
                $code .= "`$k`='$v',";
            }
        }
        $code = substr($code, 0, -1);
        return $code;
    }

    /**
     * @comment 插入數據
    
     */
    public function insert($table, $args, $debug = null)
    {
        $sql = "INSERT INTO `$table` SET ";
        $code = $this->getCode($table, $args);
        $sql .= $code;
        if ($debug) echo $sql;
        if ($this->dbh->exec($sql)) {
            $this->getPDOError();
            return $this->dbh->lastInsertId();
        }
        return false;
    }

    //查詢數據
    public function fetch($table, $condition = '', $sort = '', $page = '', $field = '*', $debug = false)
    {
        $sql = "SELECT {$field} FROM `{$table}`";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($sort != '') {
            $sql .= " ORDER BY $sort";
        }
        if ($page != '') {
            $page_size = self::page_size;
            $limit = ($page - 1) * $page_size;
            $sql .= " LIMIT $limit , $page_size";
        }
        if ($debug) echo $sql;
        $this->sth = $this->dbh->query($sql);
        $this->getPDOError();
        $this->sth->setFetchMode(PDO::FETCH_ASSOC);
        $result = $this->sth->fetchAll();
        $this->sth = null;
        return $result;
    }

    //查詢數據
    public function fetchOne($table, $condition = null, $field = '*', $debug = false)
    {
        $sql = "SELECT {$field} FROM `{$table}`";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($debug) echo $sql;
        $this->sth = $this->dbh->query($sql);
        $this->getPDOError();
        $this->sth->setFetchMode(PDO::FETCH_ASSOC);
        $result = $this->sth->fetch();
        $this->sth = null;
        return $result;
    }

    /**
     * @comment查詢數據 返回id
    
     * @return
     */
    public function fetchId($table, $condition = null, $debug = false)
    {
        $sql = "SELECT id FROM `{$table}`";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($debug) echo $sql;
        $this->sth = $this->dbh->query($sql);
        $this->getPDOError();
        $this->sth->setFetchMode(PDO::FETCH_ASSOC);
        $result = $this->sth->fetch();
        $this->sth = null;
        return $result['id'];
    }

    //獲取查詢條件
    public function getCondition($condition = '')
    {
        if ($condition != '') {
            $con = ' WHERE';
            if (is_array($condition)) {
                $i = 0;
                foreach ($condition as $k => $v) {
                    if ($i != 0) {
                        $con .= " AND $k = '$v'";
                    } else {
                        $con .= " $k = '$v'";
                    }
                    $i++;
                }
            } elseif (is_string($condition)) {
                $con .= " $condition";
            } else {
                return false;
            }
            return $con;
        }
        return false;
    }

    //獲取記錄總數
    public function counts($table, $condition = '', $debug = false)
    {
        $sql = "SELECT COUNT(*) AS num FROM `$table`";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($debug) echo $sql;
        $count = $this->dbh->query($sql);
        $this->getPDOError();
        return $count->fetchColumn();
    }

    /** 返回單條數據
     * @param $sql
     * @param bool $debug
     */
    public function doSqlOne($sql,$debug = false){
        return $this->doSql($sql,'only',$debug);
    }


    /*** 返回多條數據
     * @param $sql
     * @param string $model
     * @param bool $debug
     * @return mixed
     */
    public function doSql($sql, $model = 'many', $debug = false)
    {
        if ($debug) echo $sql;
        $this->sth = $this->dbh->query($sql);
        $this->getPDOError();
        $this->sth->setFetchMode(PDO::FETCH_ASSOC);
        if ($model == 'many') {
            $result = $this->sth->fetchAll();
        } else {
            $result = $this->sth->fetch();
        }
        $this->sth = null;
        return $result;
    }

    //修改數據
    public function update($table, $args, $condition, $debug = null)
    {

        $code = $this->getCode($table, $args);
        $sql = "UPDATE `$table` SET ";
        $sql .= $code;
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($debug) echo $sql;
        if (($rows = $this->dbh->exec($sql)) > 0) {
            $this->getPDOError();
            return $rows;
        }
        return false;
    }

    //字段遞增
    public function increase($table, $condition, $field, $debug = false)
    {
        $sql = "UPDATE `$table` SET $field = $field + 1";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        }
        if ($debug) echo $sql;
        if (($rows = $this->dbh->exec($sql)) > 0) {
            $this->getPDOError();
            return $rows;
        }
        return false;
    }

    //刪除記錄
    public function del($table, $condition, $debug = false)
    {
        $sql = "DELETE FROM `$table`";
        if (false !== ($con = $this->getCondition($condition))) {
            $sql .= $con;
        } else {
            exit('條件錯誤!');
        }
        if ($debug) echo $sql;
        if (($rows = $this->dbh->exec($sql)) > 0) {
            $this->getPDOError();
            return $rows;
        } else {
            return false;
        }
    }


    /**
     * 執行無返回值的SQL查詢
     *
     */
    public function execute($sql)
    {
        $this->dbh->exec($sql);
        $id = $this->dbh->lastInsertId();
        $data = array();
        if ($id) {
            $data['info'] = '成功';
            $data['status'] = 'T';
            $data['id'] = $id;
        } else {
            $err_info = $this->dbh->errorInfo();
            $data['info'] = $err_info[2];
            $data['status'] = 'F';
        }
        return $data;
    }

    /**
     * 捕獲PDO錯誤信息
     */
    private function getPDOError()
    {
        $err_info = '';
        if ($this->dbh->errorCode() != '00000') {
            $error = $this->dbh->errorInfo();
            if (strstr($error[2], 'Duplicate entry')) {
                $err_info = '總登記號重複';
            } else {
                $err_info = $error[2];
            }
        }
        return $err_info;
    }

    //關閉數據連接
    public function __destruct()
    {
        $this->dbh = null;
    }
}