PHP数据库操作

一、mysql链接数据库:(本扩展自 PHP 5.5.0 起已废弃,并在将来会被移除。应使用 MySQLiPDO_MySQL 扩展

$con=mysql_connect('localhost','root','123456');
if(!$con){

    die("could not connect to the database: " . mysql_error());//诊断连接错误

}
mysql_set_charset('utf8');

mysql_select_db('表名');

增:

$sql="INSERT INTO `表名`(`字段名`,`字段名`) VALUES('{变量}','{变量}')";
$re=mysql_query($sql);
$id=mysql_insert_id();

if($re){
  echo '添加成功'.'添加的数据库ID为'.$id;
}else{
  echo '添加失败';
}

删:

$sql="DELETE FROM `表名` WHERE id='{条件变量}'";//删除一定要书写条件,防止误删

$re=mysql_query($sql);

if($re){
  echo '删除成功';
}else{
  echo '删除失败';
}

改:

$sql="UPDATE `表名` SET `字段名`='{变量}' WHERE `id`='{条件变量}'";

$re=mysql_query($sql);

if($re){
  echo '修改成功';
}else{
  echo '修改失败';
}

查:

$sql="SELECT * FROM `表名` WHERE `id`='{条件变量}'";

//获取一条,一维数组

$result=mysql_query($sql);

$data=mysql_fetch_array($result,MYSQL_ASSOC);

//获取多条,二维数组

$result=mysql_query($sql);
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
  $data[]=$res;
}
return $data;

二、mysqli链接数据库:

1、面向过程

$con=mysqli_connect('localhost','root','123456','data');
if(!$con){
  die( "连接错误: " . mysqli_connect_error());
}
mysqli_set_charset($con,'utf8');

增:

$sql="INSERT INTO `表名`(`字段名`,`字段名`) VALUES('{变量}','{变量}')";
$re=mysqli_query($con,$sql);
$id=mysqli_insert_id($con);

if($re){
  echo '添加成功'.'添加的数据库ID为'.$id;
}else{
  echo '添加失败';
}

删:

$sql="DELETE FROM `表名` WHERE id='{条件变量}'";//删除一定要书写条件,防止误删

$re=mysqli_query($con,$sql);

if($re){
  echo '删除成功';
}else{
  echo '删除失败';
}

改:

$sql="UPDATE `表名` SET `字段名`='{变量}' WHERE `id`='{条件变量}'";

$re=mysqli_query($con,$sql);

if($re){
  echo '修改成功';
}else{
  echo '修改失败';
}

查:

$sql="SELECT * FROM `表名` WHERE `id`='{条件变量}'";

//获取一条,一维数组

$result=mysqli_query($con,$sql);

$data=mysqli_fetch_array($result,MYSQLI_ASSOC);

//获取多条,二维数组

$result=mysqli_query($con,$sql);
while($res=mysqli_fetch_array($result,MYSQLI_ASSOC)){
$data[]=$res;
}

2、面向对象

$mysqli = new mysqli("localhost", "root", "123456", "表名");

if($mysqli->connect_errno){//连接成功errno应该为0

  die('Connect Error:'.$mysqli->connect_error);

}

$mysqli->set_charset('utf8');

增:

$sql="INSERT INTO `表名`(`字段名`,`字段名`) VALUES('{变量}','{变量}')";

$res = $mysqli->query($sql);

//插入成功返回真,插入失败返回假

if($res){

//插入成功则输出自增主键的id和受影响行数

echo "AUTO_INCREMENT:".$mysqli->insert_id; echo "<hr/>"; echo "AFFECTED ROWS:".$mysqli->affected_rows;

}else{

//插入失败则输出错误编号和错误信息

echo "Error:"; echo $mysqli->errno.":".$mysqli->error;

}

删:

$sql="DELETE FROM `表名` WHERE id='{条件变量}'";//删除一定要书写条件,防止误删

$res = $mysqli->query($sql);

//删除成功返回真,删除失败返回假

if($re){
  echo '删除成功';
}else{
  echo '删除失败';
}

改:

$sql="UPDATE `表名` SET `字段名`='{变量}' WHERE `id`='{条件变量}'";

$res = $mysqli->query($sql);

//插入成功返回真,插入失败返回假

if($res){
  echo '修改成功';
}else{
  echo '修改失败';
}

查:

$sql="SELECT * FROM `表名` WHERE `id`='{条件变量}'";

//获取一条,一维数组

$mysqli_result = $mysqli->query($sql);//获取查询结果集

$data = $mysqli_result->fetch_array(MYSQLI_ASSOC); //关联数组

//获取多条,二维数组

$mysqli_result = $mysqli->query($query);

while($row = $mysqli_result->fetch_array(MYSQLI_ASSOC)){

  $data[] = $row;

};

 

 

三、PDO扩展链接数据库:

$mysql_conf = array(

'host' => '127.0.0.1:3306',

'db' => 'test',

'db_user' => 'root',

'db_pwd' => '123456',

);

$pdo = new PDO("mysql:host=" . $mysql_conf['host'] . ";dbname=" . $mysql_conf['db'], $mysql_conf['db_user'], $mysql_conf['db_pwd']);//创建一个pdo对象

$pdo->exec("set names 'utf8'");

$sql = "select * from user where name = '条件变量'";

$stmt = $pdo->prepare($sql);

$stmt->bindValue(1, 'joshua', PDO::PARAM_STR);

$rs = $stmt->execute();

if ($rs) {

// PDO::FETCH_ASSOC 关联数组形式 // PDO::FETCH_NUM 数字索引数组形式

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {

   var_dump($row);

} }

原文地址:https://www.cnblogs.com/baiyi-ying/p/8487357.html