执行环境 WAMP
mysql_connect
数据库连接
test.php
<?php
header("Content-type:text/html;charset=utf-8");
if($con=mysql_connect('localhost','root','')){
echo '连接成功';
}else{
echo '连接失败';
}
?>
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数据库扩展
$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password');
mysqli扩展
$link = mysqli_connect('mysql_host', 'mysql_user', 'mysql_password');
PDO扩展
$dsn = 'mysql:dbname=testdb;host=127.0.0.1';
$user = 'dbuser';
$password = 'dbpass';
$dbh = new PDO($dsn, $user, $password);
mysql_close
if($con=mysql_connect('localhost','root','')){
echo '连接成功';
}else{
echo '连接失败';
}
echo mysql_close($con);//1
mysql_select_db
<?php
header("Content-type:text/html;charset=utf-8");
if($con=mysql_connect('localhost','root','')){
echo '连接成功'."<br/>";
}else{
echo '连接失败'."<br/>";
}
if(mysql_select_db('info')){
echo "选择数据库成功";
}else{
echo "选择数据库失败";
}
?>
连接成功
选择数据库成功
<?php
header("Content-type:text/html;charset=utf-8");
$host = '127.0.0.1';
$user = 'root';
$pass = '';
//在这里编写数据库连接代码
echo $link=mysql_connect($host,$user,$pass);//Resource id #3
echo mysql_select_db('info');//1
echo mysql_query("set names 'utf8'");//1 设置当前连接使用的字符编码
?>
mysql_query
<?php
header("Content-type:text/html;charset=utf-8");
if ($con = mysql_connect('localhost', 'root', '')) {
echo '连接成功' . "<br/>";
} else {
echo '连接失败' . "<br/>";
}
if (mysql_select_db('info')) {
echo "选择数据库成功"."<br/>";
} else {
echo "选择数据库失败"."<br/>";
}
if(mysql_query('insert into test(name) values("abc")')){
echo '插入成功';
}else{
echo "插入失败";
}
mysql_close($con);
?>
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连接成功
选择数据库成功
插入成功
$res = mysql_query('select * from user limit 1');
$row = mysql_fetch_array($res);
var_dump($row);
array
0 => string '1' (length=1)
'id' => string '1' (length=1)
1 => string 'abc' (length=3)
'name' => string 'abc' (length=3)
多个连接
$link1 = mysql_connect('127.0.0.1', 'code1', '');
$link2 = mysql_connect('127.0.0.1', 'code1', '', true); //开启一个新的连接
$res = mysql_query('select * from user limit 1', $link1); //从第一个连接中查询数据
在mysql中，执行插入语句以后，可以得到自增的主键id,通过PHP的mysql_insert_id函数可以获取该id。
$uid = mysql_insert_id();
这个id的作用非常大，通常可以用来判断是否插入成功，或者作为关联ID进行其他的数据操作。
smysql_error()
echo mysql_error();
$name = '李四';
$age = 18;
$class = '高三一班';
$sql = "insert into user(name, age, class) values('$name', '$age', '$class')";
mysql_query($sql); //执行插入语句
You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near 'insert2 into
test(name) values("abc")' at line 1插入失败
mysql_insert_id()
<?php
mysql_connect('127.0.0.1','root','');
mysql_select_db('info');
mysql_query("set names 'utf8'");
$name='李四';
$age=18;
$class='高三一班';
$sql="insert into test(name) values('$name')";
mysql_query($sql);
$uid=mysql_insert_id();
echo $uid;//返回插入的id
?>
