demo1
//用预处理技术一次插入三个数据
//1.连接数据库
$mysqli=new mysqli('localhost','root','','test');
if($mysqli->connect_error){
die('连接失败'.$mysqli->connect_error);
}
$mysqli->query("set names utf8");
//2.转换成预处理对象prepare()
$sql="insert into user (username,password,age) values (?,?,?)";
$mysqli_stmt=$mysqli->prepare($sql) or die($mysqli->error);
//3.绑定变量
$username='李小龙';
$password='123456';
$age=33;
$mysqli_stmt->bind_param('ssi',$username,$password,$age);
//4.执行预处理语句
$res = $mysqli_stmt->execute();
//3.绑定变量
$username='成龙';
$password='123456';
$age=60;
$mysqli_stmt->bind_param('ssi',$username,$password,$age);
//4.执行预处理语句
$res = $mysqli_stmt->execute();
if($res){
echo '操作成功';
}else{
echo $mysqli_stmt->error;
}
//5.关闭连接
$mysqli_stmt->close();
$mysqli->close();
demo2
//用预处理技术查询id>5的数据,并显示到网页
//1.连接数据库
$mysqli=new mysqli('localhost','root','','test');
if($mysqli->connect_error){
die('连接失败'.$mysqli->connect_error);
}
$mysqli->query("set names utf8");
//2.转换成预处理对象
$sql="select username,age from user where id>?";
$mysqli_stmt=$mysqli->prepare($sql) or die($mysqli->error);
//3.绑定变量和结果集
$id=5;
$mysqli_stmt->bind_param('i',$id);
$mysqli_stmt->bind_result($username,$age);
//4.执行预处理语句
$mysqli_stmt->execute();
while($row=$mysqli_stmt->fetch()){
echo "<br />--$username--$age";
}
echo "<br />*******************************<br />";
$id=8;
$mysqli_stmt->bind_param('i',$id);
$mysqli_stmt->bind_result($username,$age);
//4.执行预处理语句
$mysqli_stmt->execute();
while($row=$mysqli_stmt->fetch()){
echo "<br />--$username--$age";
}
//5.释放资源,关闭预编译,关闭连接
$mysqli_stmt->free_result();
$mysqli_stmt->close();
$mysqli->close();
demo3
//传入一个表名,打印出表
function showTab($tab){
//1.连接数据库
$mysqli=new mysqli('localhost','root','','test');
if($mysqli->connect_error){
die('连接失败'.$mysqli->connect_error);
}
$mysqli->query("set names utf8");
//$sql="select * from $tab";
$sql = "desc $tab";
$res=$mysqli->query($sql);
//得到列和行
//$colum=$res->field_count;
//$row=$res->num_rows;
echo "<table border='1'>";
//打印表头
echo "<tr>";
while($finfo=$res->fetch_field()){
echo "<th>$finfo->name</th>";
}
echo "</tr>";
//打印表内容
while($row=$res->fetch_row()){
echo "<tr>";
foreach($row as $v){
echo "<td>$v</td>";
}
echo "<tr>";
}
echo "</table>";
}
showTab('user');