【CI PDO】CI框架下 Mysql PDO 使用方法小记

1、设置pdo链接配置信息

my_config.php

$config['mysql_host'] = 'mysql:dbname=test_db;host=127.0.0.1';
$config['mysql_username'] = 'root';
$config['mysql_passwd'] = '1234';
$config['mysql_db'] = 'test_db';
$config['dbdriver'] = 'pdo';

database.php

include(APPPATH."config/my_config.php");

......

$db['default']['hostname'] = $config['mysql_host'];
$db['default']['username'] = $config['mysql_username'];
$db['default']['password'] = $config['mysql_passwd'];
$db['default']['database'] = $config['mysql_db'];
$db['default']['dbdriver'] = $config['dbdriver'];

2、手动链接数据库

$this->load->database();

3、常见pdo数据库操作

3.1 查询

// 查询
$sql1 = "SELECT * FROM tbl_test1 WHERE condition1 = :condition1 and condition2 = :condition2";
$sql_data1 = Array(
	":condition1" => 1,
	":condition2" => "abc"
);
$sth1 = $this->db->conn_id->prepare($sql1);
$sth1->execute($sql_data1);
// 获取一条
$result1 = $sth1->fetch(PDO::FETCH_ASSOC);
// 获取所有
// $result1 = $sth1->fetchAll(PDO::FETCH_ASSOC);

// 判断是否成功
if($result1){
	// 查询成功
}else{
	// 查询失败
}

3.2 更新

// 更新
$sql2 = "UPDATE tbl_test1 SET `key1` = :val1, `key2` = :val2 WHERE  condition1 = :condition1 and condition2 = :condition2";
$sql_data2 = Array(
	":val1" => 1,
	":val2" => "hello",
	":condition1" => 1,
	":condition2" => "abc"
);
$sth2 = $this->db->conn_id->prepare($sql2);
$sth2->execute($sql_data2);

// 判断是否成功
if($sth2->rowCount() >0){
	// 更新成功
}else{
	// 更新失败
}

3.3 插入

// 插入
$sql3 = "INSERT INTO tbl_test1 (`key1`,`key2`,`key3`,`key4`,`key5`) VALUES ( :val1 , :val2 , :val3 , :val4 , :val5 )";
$sql_data3 = Array(
	"val1" => 1,
	"val2" => "hello",
	"val3" => 100.25,
	"val4" => "随便写写"
	"val5" => "2015-10-30"
);
$sth3 = $this->db->conn_id->prepare($sql3);
$result3 = $sth3->execute($sql_data3);

// 判断是否成功
if($result3){
	// 插入成功
	// 最新插入的数据的自增长id
	// $this->db->conn_id->lastInsertId();
}else{
	// 插入失败
	if($sth3->errorCode() == 23000){
		// 409，需要唯一的字段冲突重复了			
	}else{
		// 其它
	}
}

3.4 事务

// 事务
// 所有select语句都可以在事务开启前操作，即使查询不成功，也不会影响数据的完整性
// insert、update、delete相互关联，涉及数据完整性的操作，需要放在事务内部，一旦其中有一个操作失败，就进行事务回滚，以确保事务完整

try{

	// do select here
	
	// 关闭 PDO 的自动提交
	$this->db->conn_id->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
	
	// 开启异常处理
	$this->db->conn_id->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	
	// 开启一个事务
	$this->db->conn_id->beginTransaction();	
	
	// do insert、update、delete
	// insert、update、delete失败的时候抛出异常
	if($sth2->rowCount() <= 0){
		throw new PDOException('Update Failed');
	}

	// 手动提交
	$this->db->conn_id->commit();
}catch(PDOException $e){
	// 事务回滚，抛出异常
	$this->db->conn_id->rollBack();
	$return = Array(
		"code" => 500,
		"data" => $e->getMessage()
	);
	return $return;
}