本文实例讲述了PHP的PDO常用类库。分享给大家供大家参考，具体如下：

1、Db.class.php 连接数据库

// 连接数据库

class Db {

static public function getDB() {

try {

$pdo = new PDO(DB_DSN, DB_USER, DB_PWD);

$pdo->setAttribute(PDO::ATTR_PERSISTENT, true); // 设置数据库连接为持久连接

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // 设置抛出错误

$pdo->setAttribute(PDO::ATTR_ORACLE_NULLS, true); // 设置当字符串为空转换为 SQL 的 NULL

$pdo->query('SET NAMES utf8'); // 设置数据库编码

} catch (PDOException $e) {

exit('数据库连接错误，错误信息：'. $e->getMessage());

}

return $pdo;

}

}

?>

2、Model.class.php 数据库操作类

/**

* 数据库操作类库

* author Lee.

* Last modify $Date: 2012-1-19 13:59；04 $

*/

class M {

private $_db; //数据库句柄

public $_sql; //SQL语句

/**

* 构造方法

*/

public function __construct() {

$this->_db = Db::getDB();

}

/**

* 数据库添加操作

* @param string $tName 表名

* @param array $field 字段数组

* @param array $val 值数组

* @param bool $is_lastInsertId 是否返回添加ID

* @return int 默认返回成功与否，$is_lastInsertId 为true，返回添加ID

*/

public function insert($tName, $fields, $vals, $is_lastInsertId=FALSE) {

try {

if (!is_array($fields) || !is_array($vals))

exit($this->getError(__FUNCTION__, __LINE__));

$fields = $this->formatArr($fields);

$vals = $this->formatArr($vals, false);

$tName = $this->formatTabName($tName);

$this->_sql = "INSERT INTO {$tName} ({$fields}) VALUES ({$vals})";

if (!$is_lastInsertId) {

$row = $this->_db->exec($this->_sql);

return $row;

} else {

$this->_db->exec($this->_sql);

$lastId = (int)$this->_db->lastInsertId();

return $lastId;

}

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 数据库修改操作

* @param string $tName 表名

* @param array $field 字段数组

* @param array $val 值数组

* @param string $condition 条件

* @return int 受影响的行数

*/

public function update($tName, $fieldVal, $condition) {

try {

if (!is_array($fieldVal) || !is_string($tName) || !is_string($condition))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$upStr = '';

foreach ($fieldVal as $k=>$v) {

$upStr .= '`'.$k . '`=' . '\'' . $v . '\'' . ',';

}

$upStr = rtrim($upStr, ',');

$this->_sql = "UPDATE {$tName} SET {$upStr} WHERE {$condition}";

$row = $this->_db->exec($this->_sql);

return $row;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 数据库删除操作（注：必须添加 where 条件）

* @param string $tName 表名

* @param string $condition 条件

* @return int 受影响的行数

*/

public function del($tName, $condition) {

try {

if (!is_string($tName) || !is_string($condition))

exit($this->getError(__FUNCTION__, __LINE__));

$tName= $this->formatTabName($tName);

$this->_sql = "DELETE FROM {$tName} WHERE {$condition}";

$row = $this->_db->exec($this->_sql);

return $row;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 返回表总个数

* @param string $tName 表名

* @param string $condition 条件

* @return int

*/

public function total($tName, $condition='') {

try {

if (!is_string($tName))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$this->_sql = "SELECT COUNT(*) AS total FROM {$tName}" .

($condition=='' ? '' : ' WHERE ' . $condition);

$re = $this->_db->query($this->_sql);

foreach ($re as $v) {

$total = $v['total'];

}

return (int)$total;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 数据库删除多条数据

* @param string $tName 表名

* @param string $field 依赖字段

* @param array $ids 删除数组

* @return int 受影响的行数

*/

public function delMulti($tName, $field, $ids) {

try {

if (!is_string($tName) || !is_array($ids))

exit($this->getError(__FUNCTION__, __LINE__));

$delStr = '';

$tName = $this->formatTabName($tName);

$field = $this->formatTabName($field);

foreach ($ids as $v) {

$delStr .= $v . ',';

}

$delStr = rtrim($delStr, ',');

$this->_sql = "DELETE FROM {$tName} WHERE {$field} IN ({$delStr})";

$row = $this->_db->exec($this->_sql);

return $row;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 获取表格的最后主键（注：针对 INT 类型）

* @param string $tName 表名

* @return int

*/

public function insertId($tName) {

try {

if (!is_string($tName))

exit($this->getError(__FUNCTION__, __LINE__));

$this->_sql = "SHOW TABLE STATUS LIKE '{$tName}'";

$result = $this->_db->query($this->_sql);

$insert_id = 0;

foreach ($result as $v) {

$insert_id = $v['Auto_increment'];

}

return (int)$insert_id;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 检查数据是否已经存在（依赖条件）

* @param string $tName 表名

* @param string $field 依赖的字段

* @return bool

*/

public function exists($tName, $condition) {

try {

if (!is_string($tName) || !is_string($condition))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$this->_sql = "SELECT COUNT(*) AS total FROM {$tName} WHERE {$condition}";

$result = $this->_db->query($this->_sql);

foreach ($result as $v) {

$b = $v['total'];

}

if ($b) {

return true;

} else {

return false;

}

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 检查数据是否已经存在（依赖 INT 主键）

* @param string $tName 表名

* @param string $primary 主键

* @param int $id 主键值

* @return bool

*/

public function existsByPK($tName, $primary, $id) {

try {

if (!is_string($tName) || !is_string($primary)

|| !is_int($id))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$this->_sql = "SELECT COUNT(*) AS total FROM {$tName} WHERE {$primary} = ". $id;

$result = $this->_db->query($this->_sql);

foreach ($result as $v) {

$b = $v['total'];

}

if ($b) {

return true;

} else {

return false;

}

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 预处理删除（注：针对主键为 INT 类型，推荐使用）

* @param string $tName 表名

* @param string $primary 主键字段

* @param int or array or string $ids 如果是删除一条为 INT，多条为 array，删除一个范围为 string

* @return int 返回受影响的行数

*/

public function delByPK($tName, $primary, $ids, $mult=FALSE) {

try {

if (!is_string($tName) || !is_string($primary)

|| (!is_int($ids) && !is_array($ids) && !is_string($ids))

|| !is_bool($mult)) exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$stmt = $this->_db->prepare("DELETE FROM {$tName} WHERE {$primary}=?");

if (!$mult) {

$stmt->bindParam(1, $ids);

$row = $stmt->execute();

} else {

if (is_array($ids)) {

$row = 0;

foreach ($ids as $v) {

$stmt->bindParam(1, $v);

if ($stmt->execute()) {

$row++;

}

}

} elseif (is_string($ids)) {

if (!strpos($ids, '-'))

exit($this->getError(__FUNCTION__, __LINE__));

$split = explode('-', $ids);

if (count($split)!=2 || $split[0]>$split[1])

exit($this->getError(__FUNCTION__, __LINE__));

$i = null;

$count = $split[1]-$split[0]+1;

for ($i=0; $i<$count; $i++) {

$idArr[$i] = $split[0]++;

}

$idStr = '';

foreach ($idArr as $id) {

$idStr .= $id . ',';

}

$idStr = rtrim($idStr, ',');

$this->_sql ="DELETE FROM {$tName} WHERE {$primary} in ({$idStr})";

$row = $this->_db->exec($this->_sql);

}

}

return $row;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 返回单个字段数据或单条记录

* @param string $tName 表名

* @param string $condition 条件

* @param string or array $fields 返回的字段，默认是*

* @return string || array

*/

public function getRow($tName, $condition='', $fields="*") {

try {

if (!is_string($tName) || !is_string($condition)

|| !is_string($fields) || empty($fields))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$this->_sql = "SELECT {$fields} FROM {$tName} ";

$this->_sql .= ($condition=='' ? '' : "WHERE {$condition}") . " LIMIT 1";

$sth = $this->_db->prepare($this->_sql);

$sth->execute();

$result = $sth->fetch(PDO::FETCH_ASSOC);

if ($fields === '*') {

return $result;

} else {

return $result[$fields];

}

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 返回多条数据

* @param string $tName 表名

* @param string $fields 返回字段，默认为*

* @param string $condition 条件

* @param string $order 排序

* @param string $limit 显示个数

* @return PDOStatement

*/

public function getAll($tName, $fields='*', $condition='', $order='', $limit='') {

try {

if (!is_string($tName) || !is_string($fields)

|| !is_string($condition) || !is_string($order)

|| !is_string($limit))

exit($this->getError(__FUNCTION__, __LINE__));

$tName = $this->formatTabName($tName);

$fields = ($fields=='*' || $fields=='') ? '*' : $fields;

$condition = $condition=='' ? '' : " WHERE ". $condition ;

$order = $order=='' ? '' : " ORDER BY ". $order;

$limit = $limit=='' ? '' : " LIMIT ". $limit;

$this->_sql = "SELECT {$fields} FROM {$tName} {$condition} {$order} {$limit}";

$sth = $this->_db->prepare($this->_sql);

$sth->execute();

$result = $sth->fetchAll(PDO::FETCH_ASSOC);

return $result;

} catch (PDOException $e) {

exit($e->getMessage());

}

}

/**

* 格式化数组（表结构和值）

* @param array $field

* @param bool $isField

* @return string

*/

private function formatArr($field, $isField=TRUE) {

if (!is_array($field)) exit($this->getError(__FUNCTION__, __LINE__));

$fields = '';

if ($isField) {

foreach ($field as $v) {

$fields .= '`'.$v.'`,';

}

} else {

foreach ($field as $v) {

$fields .= '\''.$v.'\''.',';

}

}

$fields = rtrim($fields, ',');

return $fields;

}

/**

* 格式化问号

* @param int $count 数量

* @return string 返回格式化后的字符串

*/

private function formatMark($count) {

$str = '';

if (!is_int($count)) exit($this->getError(__FUNCTION__, __LINE__));

if ($count==1) return '?';

for ($i=0; $i<$count; $i++) {

$str .= '?,';

}

return rtrim($str, ',');

}

/**

* 错误提示

* @param string $fun

* @return string

*/

private function getError($fun, $line) {

return __CLASS__ . '->' . $fun . '() line'. $line .' ERROR!';

}

/**

* 处理表名

* @param string $tName

* @return string

*/

private function formatTabName($tName) {

return '`' . trim($tName, '`') . '`';

}

/**

* 析构方法

*/

public function __destruct() {

$this->_db = null;

}

}

希望本文所述对大家PHP程序设计有所帮助。